Related
Many in-house solutions come to mind. Like having the properties in a database and poll it every N secs. Then also check the timestamp modification for a .properties file and reload it.
But I was looking in Java EE standards and spring boot docs and I can't seem to find some best way of doing it.
I need my application to read a properties file(or env. variables or DB parameters), then be able to re-read them. What is the best practice being used in production?
A correct answer will at least solve one scenario (Spring Boot or Java EE) and provide a conceptual clue on how to make it work on the other
After further research, reloading properties must be carefully considered. In Spring, for example, we can reload the 'current' values of properties without much problem. But. Special care must be taken when resources were initialized at the context initialization time based on the values that were present in the application.properties file (e.g. Datasources, connection pools, queues, etc.).
NOTE:
The abstract classes used for Spring and Java EE are not the best example of clean code. But it is easy to use and it does address this basic initial requirements:
No usage of external libraries other than Java 8 Classes.
Only one file to solve the problem (~160 lines for the Java EE version).
Usage of standard Java Properties UTF-8 encoded file available in the File System.
Support encrypted properties.
For Spring Boot
This code helps with hot-reloading application.properties file without the usage of a Spring Cloud Config server (which may be overkill for some use cases)
This abstract class you may just copy & paste (SO goodies :D ) It's a code derived from this SO answer
// imports from java/spring/lombok
public abstract class ReloadableProperties {
#Autowired
protected StandardEnvironment environment;
private long lastModTime = 0L;
private Path configPath = null;
private PropertySource<?> appConfigPropertySource = null;
#PostConstruct
private void stopIfProblemsCreatingContext() {
System.out.println("reloading");
MutablePropertySources propertySources = environment.getPropertySources();
Optional<PropertySource<?>> appConfigPsOp =
StreamSupport.stream(propertySources.spliterator(), false)
.filter(ps -> ps.getName().matches("^.*applicationConfig.*file:.*$"))
.findFirst();
if (!appConfigPsOp.isPresent()) {
// this will stop context initialization
// (i.e. kill the spring boot program before it initializes)
throw new RuntimeException("Unable to find property Source as file");
}
appConfigPropertySource = appConfigPsOp.get();
String filename = appConfigPropertySource.getName();
filename = filename
.replace("applicationConfig: [file:", "")
.replaceAll("\\]$", "");
configPath = Paths.get(filename);
}
#Scheduled(fixedRate=2000)
private void reload() throws IOException {
System.out.println("reloading...");
long currentModTs = Files.getLastModifiedTime(configPath).toMillis();
if (currentModTs > lastModTime) {
lastModTime = currentModTs;
Properties properties = new Properties();
#Cleanup InputStream inputStream = Files.newInputStream(configPath);
properties.load(inputStream);
environment.getPropertySources()
.replace(
appConfigPropertySource.getName(),
new PropertiesPropertySource(
appConfigPropertySource.getName(),
properties
)
);
System.out.println("Reloaded.");
propertiesReloaded();
}
}
protected abstract void propertiesReloaded();
}
Then you make a bean class that allows retrieval of property values from applicatoin.properties that uses the abstract class
#Component
public class AppProperties extends ReloadableProperties {
public String dynamicProperty() {
return environment.getProperty("dynamic.prop");
}
public String anotherDynamicProperty() {
return environment.getProperty("another.dynamic.prop");
}
#Override
protected void propertiesReloaded() {
// do something after a change in property values was done
}
}
Make sure to add #EnableScheduling to your #SpringBootApplication
#SpringBootApplication
#EnableScheduling
public class MainApp {
public static void main(String[] args) {
SpringApplication.run(MainApp.class, args);
}
}
Now you can auto-wire the AppProperties Bean wherever you need it. Just make sure to always call the methods in it instead of saving it's value in a variable. And make sure to re-configure any resource or bean that was initialized with potentially different property values.
For now, I have only tested this with an external-and-default-found ./config/application.properties file.
For Java EE
I made a common Java SE abstract class to do the job.
You may copy & paste this:
// imports from java.* and javax.crypto.*
public abstract class ReloadableProperties {
private volatile Properties properties = null;
private volatile String propertiesPassword = null;
private volatile long lastModTimeOfFile = 0L;
private volatile long lastTimeChecked = 0L;
private volatile Path propertyFileAddress;
abstract protected void propertiesUpdated();
public class DynProp {
private final String propertyName;
public DynProp(String propertyName) {
this.propertyName = propertyName;
}
public String val() {
try {
return ReloadableProperties.this.getString(propertyName);
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
}
protected void init(Path path) {
this.propertyFileAddress = path;
initOrReloadIfNeeded();
}
private synchronized void initOrReloadIfNeeded() {
boolean firstTime = lastModTimeOfFile == 0L;
long currentTs = System.currentTimeMillis();
if ((lastTimeChecked + 3000) > currentTs)
return;
try {
File fa = propertyFileAddress.toFile();
long currModTime = fa.lastModified();
if (currModTime > lastModTimeOfFile) {
lastModTimeOfFile = currModTime;
InputStreamReader isr = new InputStreamReader(new FileInputStream(fa), StandardCharsets.UTF_8);
Properties prop = new Properties();
prop.load(isr);
properties = prop;
isr.close();
File passwordFiles = new File(fa.getAbsolutePath() + ".key");
if (passwordFiles.exists()) {
byte[] bytes = Files.readAllBytes(passwordFiles.toPath());
propertiesPassword = new String(bytes,StandardCharsets.US_ASCII);
propertiesPassword = propertiesPassword.trim();
propertiesPassword = propertiesPassword.replaceAll("(\\r|\\n)", "");
}
}
updateProperties();
if (!firstTime)
propertiesUpdated();
} catch (Exception e) {
e.printStackTrace();
}
}
private void updateProperties() {
List<DynProp> dynProps = Arrays.asList(this.getClass().getDeclaredFields())
.stream()
.filter(f -> f.getType().isAssignableFrom(DynProp.class))
.map(f-> fromField(f))
.collect(Collectors.toList());
for (DynProp dp :dynProps) {
if (!properties.containsKey(dp.propertyName)) {
System.out.println("propertyName: "+ dp.propertyName + " does not exist in property file");
}
}
for (Object key : properties.keySet()) {
if (!dynProps.stream().anyMatch(dp->dp.propertyName.equals(key.toString()))) {
System.out.println("property in file is not used in application: "+ key);
}
}
}
private DynProp fromField(Field f) {
try {
return (DynProp) f.get(this);
} catch (IllegalAccessException e) {
e.printStackTrace();
}
return null;
}
protected String getString(String param) throws Exception {
initOrReloadIfNeeded();
String value = properties.getProperty(param);
if (value.startsWith("ENC(")) {
String cipheredText = value
.replace("ENC(", "")
.replaceAll("\\)$", "");
value = decrypt(cipheredText, propertiesPassword);
}
return value;
}
public static String encrypt(String plainText, String key)
throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, InvalidKeySpecException {
SecureRandom secureRandom = new SecureRandom();
byte[] keyBytes = key.getBytes(StandardCharsets.US_ASCII);
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
KeySpec spec = new PBEKeySpec(key.toCharArray(), new byte[]{0,1,2,3,4,5,6,7}, 65536, 128);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secretKey = new SecretKeySpec(tmp.getEncoded(), "AES");
byte[] iv = new byte[12];
secureRandom.nextBytes(iv);
final Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
GCMParameterSpec parameterSpec = new GCMParameterSpec(128, iv); //128 bit auth tag length
cipher.init(Cipher.ENCRYPT_MODE, secretKey, parameterSpec);
byte[] cipherText = cipher.doFinal(plainText.getBytes(StandardCharsets.UTF_8));
ByteBuffer byteBuffer = ByteBuffer.allocate(4 + iv.length + cipherText.length);
byteBuffer.putInt(iv.length);
byteBuffer.put(iv);
byteBuffer.put(cipherText);
byte[] cipherMessage = byteBuffer.array();
String cyphertext = Base64.getEncoder().encodeToString(cipherMessage);
return cyphertext;
}
public static String decrypt(String cypherText, String key)
throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, InvalidKeySpecException {
byte[] cipherMessage = Base64.getDecoder().decode(cypherText);
ByteBuffer byteBuffer = ByteBuffer.wrap(cipherMessage);
int ivLength = byteBuffer.getInt();
if(ivLength < 12 || ivLength >= 16) { // check input parameter
throw new IllegalArgumentException("invalid iv length");
}
byte[] iv = new byte[ivLength];
byteBuffer.get(iv);
byte[] cipherText = new byte[byteBuffer.remaining()];
byteBuffer.get(cipherText);
byte[] keyBytes = key.getBytes(StandardCharsets.US_ASCII);
final Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
KeySpec spec = new PBEKeySpec(key.toCharArray(), new byte[]{0,1,2,3,4,5,6,7}, 65536, 128);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secretKey = new SecretKeySpec(tmp.getEncoded(), "AES");
cipher.init(Cipher.DECRYPT_MODE, secretKey, new GCMParameterSpec(128, iv));
byte[] plainText= cipher.doFinal(cipherText);
String plain = new String(plainText, StandardCharsets.UTF_8);
return plain;
}
}
Then you can use it this way:
public class AppProperties extends ReloadableProperties {
public static final AppProperties INSTANCE; static {
INSTANCE = new AppProperties();
INSTANCE.init(Paths.get("application.properties"));
}
#Override
protected void propertiesUpdated() {
// run code every time a property is updated
}
public final DynProp wsUrl = new DynProp("ws.url");
public final DynProp hiddenText = new DynProp("hidden.text");
}
In case you want to use encoded properties you may enclose it's value inside ENC() and a password for decryption will be searched for in the same path and name of the property file with an added .key extension. In this example it will look for the password in the application.properties.key file.
application.properties ->
ws.url=http://some webside
hidden.text=ENC(AAAADCzaasd9g61MI4l5sbCXrFNaQfQrgkxygNmFa3UuB9Y+YzRuBGYj+A==)
aplication.properties.key ->
password aca
For the encryption of property values for the Java EE solution I consulted Patrick Favre-Bulle excellent article on Symmetric Encryption with AES in Java and Android. Then checked the Cipher, block mode and padding in this SO question about AES/GCM/NoPadding. And finally I made the AES bits be derived from a password from #erickson excellent answer in SO about AES Password Based Encryption. Regarding encryption of value properties in Spring I think they are integrated with Java Simplified Encryption
Wether this qualify as a best practice or not may be out of scope. This answer shows how to have reloadable properties in Spring Boot and Java EE.
This functionality can be achieved by using a Spring Cloud Config Server and a refresh scope client.
Server
Server (Spring Boot app) serves the configuration stored, for example, in a Git repository:
#SpringBootApplication
#EnableConfigServer
public class ConfigServer {
public static void main(String[] args) {
SpringApplication.run(ConfigServer.class, args);
}
}
application.yml:
spring:
cloud:
config:
server:
git:
uri: git-repository-url-which-stores-configuration.git
configuration file configuration-client.properties (in a Git repository):
configuration.value=Old
Client
Client (Spring Boot app) reads configuration from the configuration server by using #RefreshScope annotation:
#Component
#RefreshScope
public class Foo {
#Value("${configuration.value}")
private String value;
....
}
bootstrap.yml:
spring:
application:
name: configuration-client
cloud:
config:
uri: configuration-server-url
When there is a configuration change in the Git repository:
configuration.value=New
reload the configuration variable by sending a POST request to the /refresh endpoint:
$ curl -X POST http://client-url/actuator/refresh
Now you have the new value New.
Additionally Foo class can serve the value to the rest of application via RESTful API if its changed to RestController and has a corresponding endpont.
I used #David Hofmann concept and made some changes because of not all was good.
First of all, in my case I no need auto-reload, I just call the REST controller for updating properties.
The second case #David Hofmann's approach not workable for me with outside files.
Now, this code can work with application.properties file from resources(inside the app) and from an outside place. The outside file I put near jar, and I use this --spring.config.location=app.properties argument when the application starts.
#Component
public class PropertyReloader {
private final Logger logger = LoggerFactory.getLogger(getClass());
#Autowired
private StandardEnvironment environment;
private long lastModTime = 0L;
private PropertySource<?> appConfigPropertySource = null;
private Path configPath;
private static final String PROPERTY_NAME = "app.properties";
#PostConstruct
private void createContext() {
MutablePropertySources propertySources = environment.getPropertySources();
// first of all we check if application started with external file
String property = "applicationConfig: [file:" + PROPERTY_NAME + "]";
PropertySource<?> appConfigPsOp = propertySources.get(property);
configPath = Paths.get(PROPERTY_NAME).toAbsolutePath();
if (appConfigPsOp == null) {
// if not we check properties file from resources folder
property = "class path resource [" + PROPERTY_NAME + "]";
configPath = Paths.get("src/main/resources/" + PROPERTY_NAME).toAbsolutePath();
}
appConfigPsOp = propertySources.get(property);
appConfigPropertySource = appConfigPsOp;
}
// this method I call into REST cintroller for reloading all properties after change
// app.properties file
public void reload() {
try {
long currentModTs = Files.getLastModifiedTime(configPath).toMillis();
if (currentModTs > lastModTime) {
lastModTime = currentModTs;
Properties properties = new Properties();
#Cleanup InputStream inputStream = Files.newInputStream(configPath);
properties.load(inputStream);
String property = appConfigPropertySource.getName();
PropertiesPropertySource updatedProperty = new PropertiesPropertySource(property, properties);
environment.getPropertySources().replace(property, updatedProperty);
logger.info("Configs {} were reloaded", property);
}
} catch (Exception e) {
logger.error("Can't reload config file " + e);
}
}
}
I hope that my approach will help somebody
As mentioned by #Boris, Spring Cloud Config is the way to go to avoid patchy solution. To keep the setup minimum, I will suggest the Embedding the Config Server Approach with native type (file type).
To support automatic config refresh without calling the actuator endpoint manually, I have created a directory listener to detect file changes and to dispatch refresh scope event.
Proof Of Concept repo (git)
For spring boot, there's a really good article on this topic here, but for multiple property files it doesn't work perfectly.
In my case I had 2 property files, one non sensitive and one containing the passwords. I proceeded with the following:
<dependency>
<groupId>commons-configuration</groupId>
<artifactId>commons-configuration</artifactId>
<version>1.10</version>
</dependency>
Extend the spring's PropertySource so that you can add the reloadable version to the environment.
public class ReloadablePropertySource extends PropertySource {
private final PropertiesConfiguration propertiesConfiguration;
public ReloadablePropertySource(String name, String path, ConfigurationListener listener) {
super(StringUtils.hasText(name) ? name : path);
try {
this.propertiesConfiguration = getConfiguration(path, listener);
} catch (Exception e) {
throw new MissingRequiredPropertiesException();
}
}
#Override
public Object getProperty(String s) {
return propertiesConfiguration.getProperty(s);
}
private PropertiesConfiguration getConfiguration(String path, ConfigurationListener listener) throws ConfigurationException {
PropertiesConfiguration configuration = new PropertiesConfiguration(path);
FileChangedReloadingStrategy reloadingStrategy = new FileChangedReloadingStrategy();
reloadingStrategy.setRefreshDelay(5000);
configuration.setReloadingStrategy(reloadingStrategy);
configuration.addConfigurationListener(listener);
return configuration;
}
}
Now add all of your properties files (now reloadable) inside the spring's env
#Configuration
public class ReloadablePropertySourceConfig {
private final ConfigurableEnvironment env;
#Value("${spring.config.location}")
private String appConfigPath;
#Value("${spring.config.additional-location}")
private String vaultConfigPath;
public ReloadablePropertySourceConfig(ConfigurableEnvironment env) {
this.env = env;
}
#Bean
#ConditionalOnProperty(name = "spring.config.location")
public ReloadablePropertySource getAppConfigReloadablePropertySource(){
ReloadablePropertySource rps = new ReloadablePropertySource("dynamicNonSensitive", appConfigPath, new PropertiesChangeListener());
MutablePropertySources sources = env.getPropertySources();
sources.addFirst(rps);
return rps;
}
#Bean
#ConditionalOnProperty(name = "spring.config.additional-location")
public ReloadablePropertySource getVaultReloadablePropertySource(){
ReloadablePropertySource rps = new ReloadablePropertySource("dynamicVault", vaultConfigPath, new PropertiesChangeListener());
MutablePropertySources sources = env.getPropertySources();
sources.addFirst(rps);
return rps;
}
private static class PropertiesChangeListener implements ConfigurationListener{
#Override
public void configurationChanged(ConfigurationEvent event) {
if (!event.isBeforeUpdate()){
System.out.println("config refreshed!");
}
}
}
}
From the article
We've added the new property source as the first item because we want it to override any existing property with the same key
In our case, we have 2 "reloadable" property sources and both will be looked up first.
Finally create one more class from which we can access the env's properties
#Component
public class ConfigProperties {
private final Environment environment;
public ConfigProperties(Environment environment) {
this.environment = environment;
}
public String getProperty(String name){
return environment.getProperty(name);
}
}
Now you can autowire ConfigProperties and always get the latest property in the files without requiring to restart the application.
#RestController
#Slf4j
public class TestController {
#Autowired
private ConfigProperties env;
#GetMapping("/refresh")
public String test2() {
log.info("hit");
String updatedProperty = env.getProperty("test.property");
String password = env.getProperty("db.password");
return updatedProperty + "\n" + password;
}
}
where test.property is coming from 1st file and db.password is coming from another.
If you want to change the properties at realtime and don't want to restart the server then follow the below steps:
1). Application.properties
app.name= xyz
management.endpoints.web.exposure.include=*
2). Add below dependencies in pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-rest</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-context</artifactId>
<version>2.1.1.RELEASE</version>
</dependency>
3).Place application.properties in /target/config folder. Create the jar in /target folder
4).add a classas below ApplcationProperties.java
#Component
#RefreshScope
#ConfigurationProperties(prefix = "app")
public class ApplicationProperties {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
5). Write Controller.java and inject ApplcationProperties
#RestController
public class TestController {
#Autowired
private ApplicationProperties applcationProperties;
#GetMapping("/test")
public String getString() {
return applcationProperties.getName();
}
}
6).Run the spring boot application
Call localhost:XXXX/test from your browser
Output : xyz
7). Change the value in application.properties from xyz to abc
8). Using postman send a POST request to localhost:XXXX/actuator/refresh
response: ["app.name"]
9). Call localhost:XXXX/find from your browser
Output : abc
Many in-house solutions come to mind. Like having the properties in a database and poll it every N secs. Then also check the timestamp modification for a .properties file and reload it.
But I was looking in Java EE standards and spring boot docs and I can't seem to find some best way of doing it.
I need my application to read a properties file(or env. variables or DB parameters), then be able to re-read them. What is the best practice being used in production?
A correct answer will at least solve one scenario (Spring Boot or Java EE) and provide a conceptual clue on how to make it work on the other
After further research, reloading properties must be carefully considered. In Spring, for example, we can reload the 'current' values of properties without much problem. But. Special care must be taken when resources were initialized at the context initialization time based on the values that were present in the application.properties file (e.g. Datasources, connection pools, queues, etc.).
NOTE:
The abstract classes used for Spring and Java EE are not the best example of clean code. But it is easy to use and it does address this basic initial requirements:
No usage of external libraries other than Java 8 Classes.
Only one file to solve the problem (~160 lines for the Java EE version).
Usage of standard Java Properties UTF-8 encoded file available in the File System.
Support encrypted properties.
For Spring Boot
This code helps with hot-reloading application.properties file without the usage of a Spring Cloud Config server (which may be overkill for some use cases)
This abstract class you may just copy & paste (SO goodies :D ) It's a code derived from this SO answer
// imports from java/spring/lombok
public abstract class ReloadableProperties {
#Autowired
protected StandardEnvironment environment;
private long lastModTime = 0L;
private Path configPath = null;
private PropertySource<?> appConfigPropertySource = null;
#PostConstruct
private void stopIfProblemsCreatingContext() {
System.out.println("reloading");
MutablePropertySources propertySources = environment.getPropertySources();
Optional<PropertySource<?>> appConfigPsOp =
StreamSupport.stream(propertySources.spliterator(), false)
.filter(ps -> ps.getName().matches("^.*applicationConfig.*file:.*$"))
.findFirst();
if (!appConfigPsOp.isPresent()) {
// this will stop context initialization
// (i.e. kill the spring boot program before it initializes)
throw new RuntimeException("Unable to find property Source as file");
}
appConfigPropertySource = appConfigPsOp.get();
String filename = appConfigPropertySource.getName();
filename = filename
.replace("applicationConfig: [file:", "")
.replaceAll("\\]$", "");
configPath = Paths.get(filename);
}
#Scheduled(fixedRate=2000)
private void reload() throws IOException {
System.out.println("reloading...");
long currentModTs = Files.getLastModifiedTime(configPath).toMillis();
if (currentModTs > lastModTime) {
lastModTime = currentModTs;
Properties properties = new Properties();
#Cleanup InputStream inputStream = Files.newInputStream(configPath);
properties.load(inputStream);
environment.getPropertySources()
.replace(
appConfigPropertySource.getName(),
new PropertiesPropertySource(
appConfigPropertySource.getName(),
properties
)
);
System.out.println("Reloaded.");
propertiesReloaded();
}
}
protected abstract void propertiesReloaded();
}
Then you make a bean class that allows retrieval of property values from applicatoin.properties that uses the abstract class
#Component
public class AppProperties extends ReloadableProperties {
public String dynamicProperty() {
return environment.getProperty("dynamic.prop");
}
public String anotherDynamicProperty() {
return environment.getProperty("another.dynamic.prop");
}
#Override
protected void propertiesReloaded() {
// do something after a change in property values was done
}
}
Make sure to add #EnableScheduling to your #SpringBootApplication
#SpringBootApplication
#EnableScheduling
public class MainApp {
public static void main(String[] args) {
SpringApplication.run(MainApp.class, args);
}
}
Now you can auto-wire the AppProperties Bean wherever you need it. Just make sure to always call the methods in it instead of saving it's value in a variable. And make sure to re-configure any resource or bean that was initialized with potentially different property values.
For now, I have only tested this with an external-and-default-found ./config/application.properties file.
For Java EE
I made a common Java SE abstract class to do the job.
You may copy & paste this:
// imports from java.* and javax.crypto.*
public abstract class ReloadableProperties {
private volatile Properties properties = null;
private volatile String propertiesPassword = null;
private volatile long lastModTimeOfFile = 0L;
private volatile long lastTimeChecked = 0L;
private volatile Path propertyFileAddress;
abstract protected void propertiesUpdated();
public class DynProp {
private final String propertyName;
public DynProp(String propertyName) {
this.propertyName = propertyName;
}
public String val() {
try {
return ReloadableProperties.this.getString(propertyName);
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
}
protected void init(Path path) {
this.propertyFileAddress = path;
initOrReloadIfNeeded();
}
private synchronized void initOrReloadIfNeeded() {
boolean firstTime = lastModTimeOfFile == 0L;
long currentTs = System.currentTimeMillis();
if ((lastTimeChecked + 3000) > currentTs)
return;
try {
File fa = propertyFileAddress.toFile();
long currModTime = fa.lastModified();
if (currModTime > lastModTimeOfFile) {
lastModTimeOfFile = currModTime;
InputStreamReader isr = new InputStreamReader(new FileInputStream(fa), StandardCharsets.UTF_8);
Properties prop = new Properties();
prop.load(isr);
properties = prop;
isr.close();
File passwordFiles = new File(fa.getAbsolutePath() + ".key");
if (passwordFiles.exists()) {
byte[] bytes = Files.readAllBytes(passwordFiles.toPath());
propertiesPassword = new String(bytes,StandardCharsets.US_ASCII);
propertiesPassword = propertiesPassword.trim();
propertiesPassword = propertiesPassword.replaceAll("(\\r|\\n)", "");
}
}
updateProperties();
if (!firstTime)
propertiesUpdated();
} catch (Exception e) {
e.printStackTrace();
}
}
private void updateProperties() {
List<DynProp> dynProps = Arrays.asList(this.getClass().getDeclaredFields())
.stream()
.filter(f -> f.getType().isAssignableFrom(DynProp.class))
.map(f-> fromField(f))
.collect(Collectors.toList());
for (DynProp dp :dynProps) {
if (!properties.containsKey(dp.propertyName)) {
System.out.println("propertyName: "+ dp.propertyName + " does not exist in property file");
}
}
for (Object key : properties.keySet()) {
if (!dynProps.stream().anyMatch(dp->dp.propertyName.equals(key.toString()))) {
System.out.println("property in file is not used in application: "+ key);
}
}
}
private DynProp fromField(Field f) {
try {
return (DynProp) f.get(this);
} catch (IllegalAccessException e) {
e.printStackTrace();
}
return null;
}
protected String getString(String param) throws Exception {
initOrReloadIfNeeded();
String value = properties.getProperty(param);
if (value.startsWith("ENC(")) {
String cipheredText = value
.replace("ENC(", "")
.replaceAll("\\)$", "");
value = decrypt(cipheredText, propertiesPassword);
}
return value;
}
public static String encrypt(String plainText, String key)
throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, InvalidKeySpecException {
SecureRandom secureRandom = new SecureRandom();
byte[] keyBytes = key.getBytes(StandardCharsets.US_ASCII);
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
KeySpec spec = new PBEKeySpec(key.toCharArray(), new byte[]{0,1,2,3,4,5,6,7}, 65536, 128);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secretKey = new SecretKeySpec(tmp.getEncoded(), "AES");
byte[] iv = new byte[12];
secureRandom.nextBytes(iv);
final Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
GCMParameterSpec parameterSpec = new GCMParameterSpec(128, iv); //128 bit auth tag length
cipher.init(Cipher.ENCRYPT_MODE, secretKey, parameterSpec);
byte[] cipherText = cipher.doFinal(plainText.getBytes(StandardCharsets.UTF_8));
ByteBuffer byteBuffer = ByteBuffer.allocate(4 + iv.length + cipherText.length);
byteBuffer.putInt(iv.length);
byteBuffer.put(iv);
byteBuffer.put(cipherText);
byte[] cipherMessage = byteBuffer.array();
String cyphertext = Base64.getEncoder().encodeToString(cipherMessage);
return cyphertext;
}
public static String decrypt(String cypherText, String key)
throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, InvalidKeySpecException {
byte[] cipherMessage = Base64.getDecoder().decode(cypherText);
ByteBuffer byteBuffer = ByteBuffer.wrap(cipherMessage);
int ivLength = byteBuffer.getInt();
if(ivLength < 12 || ivLength >= 16) { // check input parameter
throw new IllegalArgumentException("invalid iv length");
}
byte[] iv = new byte[ivLength];
byteBuffer.get(iv);
byte[] cipherText = new byte[byteBuffer.remaining()];
byteBuffer.get(cipherText);
byte[] keyBytes = key.getBytes(StandardCharsets.US_ASCII);
final Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
KeySpec spec = new PBEKeySpec(key.toCharArray(), new byte[]{0,1,2,3,4,5,6,7}, 65536, 128);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secretKey = new SecretKeySpec(tmp.getEncoded(), "AES");
cipher.init(Cipher.DECRYPT_MODE, secretKey, new GCMParameterSpec(128, iv));
byte[] plainText= cipher.doFinal(cipherText);
String plain = new String(plainText, StandardCharsets.UTF_8);
return plain;
}
}
Then you can use it this way:
public class AppProperties extends ReloadableProperties {
public static final AppProperties INSTANCE; static {
INSTANCE = new AppProperties();
INSTANCE.init(Paths.get("application.properties"));
}
#Override
protected void propertiesUpdated() {
// run code every time a property is updated
}
public final DynProp wsUrl = new DynProp("ws.url");
public final DynProp hiddenText = new DynProp("hidden.text");
}
In case you want to use encoded properties you may enclose it's value inside ENC() and a password for decryption will be searched for in the same path and name of the property file with an added .key extension. In this example it will look for the password in the application.properties.key file.
application.properties ->
ws.url=http://some webside
hidden.text=ENC(AAAADCzaasd9g61MI4l5sbCXrFNaQfQrgkxygNmFa3UuB9Y+YzRuBGYj+A==)
aplication.properties.key ->
password aca
For the encryption of property values for the Java EE solution I consulted Patrick Favre-Bulle excellent article on Symmetric Encryption with AES in Java and Android. Then checked the Cipher, block mode and padding in this SO question about AES/GCM/NoPadding. And finally I made the AES bits be derived from a password from #erickson excellent answer in SO about AES Password Based Encryption. Regarding encryption of value properties in Spring I think they are integrated with Java Simplified Encryption
Wether this qualify as a best practice or not may be out of scope. This answer shows how to have reloadable properties in Spring Boot and Java EE.
This functionality can be achieved by using a Spring Cloud Config Server and a refresh scope client.
Server
Server (Spring Boot app) serves the configuration stored, for example, in a Git repository:
#SpringBootApplication
#EnableConfigServer
public class ConfigServer {
public static void main(String[] args) {
SpringApplication.run(ConfigServer.class, args);
}
}
application.yml:
spring:
cloud:
config:
server:
git:
uri: git-repository-url-which-stores-configuration.git
configuration file configuration-client.properties (in a Git repository):
configuration.value=Old
Client
Client (Spring Boot app) reads configuration from the configuration server by using #RefreshScope annotation:
#Component
#RefreshScope
public class Foo {
#Value("${configuration.value}")
private String value;
....
}
bootstrap.yml:
spring:
application:
name: configuration-client
cloud:
config:
uri: configuration-server-url
When there is a configuration change in the Git repository:
configuration.value=New
reload the configuration variable by sending a POST request to the /refresh endpoint:
$ curl -X POST http://client-url/actuator/refresh
Now you have the new value New.
Additionally Foo class can serve the value to the rest of application via RESTful API if its changed to RestController and has a corresponding endpont.
I used #David Hofmann concept and made some changes because of not all was good.
First of all, in my case I no need auto-reload, I just call the REST controller for updating properties.
The second case #David Hofmann's approach not workable for me with outside files.
Now, this code can work with application.properties file from resources(inside the app) and from an outside place. The outside file I put near jar, and I use this --spring.config.location=app.properties argument when the application starts.
#Component
public class PropertyReloader {
private final Logger logger = LoggerFactory.getLogger(getClass());
#Autowired
private StandardEnvironment environment;
private long lastModTime = 0L;
private PropertySource<?> appConfigPropertySource = null;
private Path configPath;
private static final String PROPERTY_NAME = "app.properties";
#PostConstruct
private void createContext() {
MutablePropertySources propertySources = environment.getPropertySources();
// first of all we check if application started with external file
String property = "applicationConfig: [file:" + PROPERTY_NAME + "]";
PropertySource<?> appConfigPsOp = propertySources.get(property);
configPath = Paths.get(PROPERTY_NAME).toAbsolutePath();
if (appConfigPsOp == null) {
// if not we check properties file from resources folder
property = "class path resource [" + PROPERTY_NAME + "]";
configPath = Paths.get("src/main/resources/" + PROPERTY_NAME).toAbsolutePath();
}
appConfigPsOp = propertySources.get(property);
appConfigPropertySource = appConfigPsOp;
}
// this method I call into REST cintroller for reloading all properties after change
// app.properties file
public void reload() {
try {
long currentModTs = Files.getLastModifiedTime(configPath).toMillis();
if (currentModTs > lastModTime) {
lastModTime = currentModTs;
Properties properties = new Properties();
#Cleanup InputStream inputStream = Files.newInputStream(configPath);
properties.load(inputStream);
String property = appConfigPropertySource.getName();
PropertiesPropertySource updatedProperty = new PropertiesPropertySource(property, properties);
environment.getPropertySources().replace(property, updatedProperty);
logger.info("Configs {} were reloaded", property);
}
} catch (Exception e) {
logger.error("Can't reload config file " + e);
}
}
}
I hope that my approach will help somebody
As mentioned by #Boris, Spring Cloud Config is the way to go to avoid patchy solution. To keep the setup minimum, I will suggest the Embedding the Config Server Approach with native type (file type).
To support automatic config refresh without calling the actuator endpoint manually, I have created a directory listener to detect file changes and to dispatch refresh scope event.
Proof Of Concept repo (git)
For spring boot, there's a really good article on this topic here, but for multiple property files it doesn't work perfectly.
In my case I had 2 property files, one non sensitive and one containing the passwords. I proceeded with the following:
<dependency>
<groupId>commons-configuration</groupId>
<artifactId>commons-configuration</artifactId>
<version>1.10</version>
</dependency>
Extend the spring's PropertySource so that you can add the reloadable version to the environment.
public class ReloadablePropertySource extends PropertySource {
private final PropertiesConfiguration propertiesConfiguration;
public ReloadablePropertySource(String name, String path, ConfigurationListener listener) {
super(StringUtils.hasText(name) ? name : path);
try {
this.propertiesConfiguration = getConfiguration(path, listener);
} catch (Exception e) {
throw new MissingRequiredPropertiesException();
}
}
#Override
public Object getProperty(String s) {
return propertiesConfiguration.getProperty(s);
}
private PropertiesConfiguration getConfiguration(String path, ConfigurationListener listener) throws ConfigurationException {
PropertiesConfiguration configuration = new PropertiesConfiguration(path);
FileChangedReloadingStrategy reloadingStrategy = new FileChangedReloadingStrategy();
reloadingStrategy.setRefreshDelay(5000);
configuration.setReloadingStrategy(reloadingStrategy);
configuration.addConfigurationListener(listener);
return configuration;
}
}
Now add all of your properties files (now reloadable) inside the spring's env
#Configuration
public class ReloadablePropertySourceConfig {
private final ConfigurableEnvironment env;
#Value("${spring.config.location}")
private String appConfigPath;
#Value("${spring.config.additional-location}")
private String vaultConfigPath;
public ReloadablePropertySourceConfig(ConfigurableEnvironment env) {
this.env = env;
}
#Bean
#ConditionalOnProperty(name = "spring.config.location")
public ReloadablePropertySource getAppConfigReloadablePropertySource(){
ReloadablePropertySource rps = new ReloadablePropertySource("dynamicNonSensitive", appConfigPath, new PropertiesChangeListener());
MutablePropertySources sources = env.getPropertySources();
sources.addFirst(rps);
return rps;
}
#Bean
#ConditionalOnProperty(name = "spring.config.additional-location")
public ReloadablePropertySource getVaultReloadablePropertySource(){
ReloadablePropertySource rps = new ReloadablePropertySource("dynamicVault", vaultConfigPath, new PropertiesChangeListener());
MutablePropertySources sources = env.getPropertySources();
sources.addFirst(rps);
return rps;
}
private static class PropertiesChangeListener implements ConfigurationListener{
#Override
public void configurationChanged(ConfigurationEvent event) {
if (!event.isBeforeUpdate()){
System.out.println("config refreshed!");
}
}
}
}
From the article
We've added the new property source as the first item because we want it to override any existing property with the same key
In our case, we have 2 "reloadable" property sources and both will be looked up first.
Finally create one more class from which we can access the env's properties
#Component
public class ConfigProperties {
private final Environment environment;
public ConfigProperties(Environment environment) {
this.environment = environment;
}
public String getProperty(String name){
return environment.getProperty(name);
}
}
Now you can autowire ConfigProperties and always get the latest property in the files without requiring to restart the application.
#RestController
#Slf4j
public class TestController {
#Autowired
private ConfigProperties env;
#GetMapping("/refresh")
public String test2() {
log.info("hit");
String updatedProperty = env.getProperty("test.property");
String password = env.getProperty("db.password");
return updatedProperty + "\n" + password;
}
}
where test.property is coming from 1st file and db.password is coming from another.
If you want to change the properties at realtime and don't want to restart the server then follow the below steps:
1). Application.properties
app.name= xyz
management.endpoints.web.exposure.include=*
2). Add below dependencies in pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-rest</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-context</artifactId>
<version>2.1.1.RELEASE</version>
</dependency>
3).Place application.properties in /target/config folder. Create the jar in /target folder
4).add a classas below ApplcationProperties.java
#Component
#RefreshScope
#ConfigurationProperties(prefix = "app")
public class ApplicationProperties {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
5). Write Controller.java and inject ApplcationProperties
#RestController
public class TestController {
#Autowired
private ApplicationProperties applcationProperties;
#GetMapping("/test")
public String getString() {
return applcationProperties.getName();
}
}
6).Run the spring boot application
Call localhost:XXXX/test from your browser
Output : xyz
7). Change the value in application.properties from xyz to abc
8). Using postman send a POST request to localhost:XXXX/actuator/refresh
response: ["app.name"]
9). Call localhost:XXXX/find from your browser
Output : abc
Okay, so I have been given this challenge to implement a "Service" that loads in all the resources for all locales that we support. Then it should be possible to pick they resource from correct ResourceBundle based on the key and the current Locale. How can I achieve this?
So this is how I have made my solution, I have a Service called TranslationService
public class TranslationService {
private List<ResourceBundle> resourceBundles;
public TranslationService(final Locale locale) {
ResourceBundle messageTexts = ResourceBundle.getBundle("MessageTexts", locale, new Utf8Control());
ResourceBundle notificationTexts = ResourceBundle.getBundle("NotificationTexts", locale, new Utf8Control());
ResourceBundle generalTexts = ResourceBundle.getBundle("GeneralTexts", locale, new Utf8Control());
Collections.addAll(this.resourceBundles, messageTexts, notificationTexts, generalTexts);
}
public String getText(String key) {
String text = null;
for (ResourceBundle resourceBundle : resourceBundles) {
try {
text = resourceBundle.getString(key);
} catch (MissingResourceException e) {
// DO NOTHING: If the key is not found in first resource means not that it isn't in the next
// check all resources for the key.
}
}
if (text == null) {
log.error("Could not find key {} in any resource.", key);
}
return text;
}
}
So what I want to achieve is to be able to load in all the specified Bundles for all supported Locales so to say I want to load in on initialization ex the MessageTexts_en_GB.properties, MessageTexts_fr_FR.properties, MessageTexts_ja_JP.properties etc. And then based on what locale is used and what key I am sending in I should be able to tell which Bundle to look into for the key without looping through all my Bundles. So to say if I get the Locale for fr_FR and the key PUSH_NOTIFICATION_REMINDER, then I would know that I have to lookup for the text in NotificationTexts_fr_FR.properties without having to loop through all the resources as I am doing. So is it even possible to do it like this or do I have to loop through all my resources as I am doing now, and if loading resources for all Locales is possible how would I eventually need to handle property naming clashes so I do not get the wrong language property?
So I am working currently on a solution which looks like this:
public class MyResourceBundle {
private Map<Locale, Map<String, String>> localeResources;
public MyResourceBundle() {
localeResources = new HashMap<>();
for (LocaleConfig config : LocaleConfig.values()) {
Map<String, String> resources = new HashMap<>();
ResourceBundle systemTexts = ResourceBundle.getBundle("SystemTexts", config.getLocale());
ResourceBundle translationTexts = ResourceBundle.getBundle("TranslationTexts", config.getLocale());
Enumeration systemKeys = systemTexts.getKeys();
while (systemKeys.hasMoreElements()) {
String key = (String) systemKeys.nextElement();
resources.put(key, systemTexts.getString(key));
}
Enumeration translationKeys = translationTexts.getKeys();
while (translationKeys.hasMoreElements()) {
String key = (String) translationKeys.nextElement();
resources.put(key, translationTexts.getString(key));
}
localeResources.put(config.getLocale(), resources);
}
}
public String getText(Locale locale, String key) {
String text = null;
text = localeResources.get(locale).get(key);
if (text == null) {
String errorMessage = "Key: " + key + " does not exist for locale " + locale.toString();
throw new MissingResourceException(errorMessage, this.getClass().getName(), key);
}
return text;
}
}
LocaleConfig.java :
public enum LocaleConfig {
DANISH("da", "DK"),
ENGLISH("en", "GB")
;
private String language;
private String country;
LocaleConfig(String language, String country) {
this.language = language;
this.country = country;
}
public Locale getLocale() {
return new Locale(language, country);
}
}
SystemTexts_da_DK.properties:
PERSON_1=Hans Hansen
PERSON_2=Anders Andersen
PERSON_3=Ib Ibsen
REMINDER_MESSAGE=Husk at teste...
SystemTexts_en_GB.properties:
PERSON_1=Frank Testerson
PERSON_2=Julie Testerson
PERSON_3=Test Testerson
REMINDER_MESSAGE=Remember to test...
TranslationTexts_da_DK.properties:
NOTE_NEW=Ny
NOTE_SEEN=Set
TranslationTexts_en_GB.properties:
NOTE_NEW=New
NOTE_SEEN=Seen
Now I can just call:
public class MyResourceBundleExample {
public static void main(String[] args) {
Locale locale = new Locale("da", "DK");
MyResourceBundle myResourceBundle = new MyResourceBundle();
System.out.println(myResourceBundle.getText(locale, "PERSON_3"));
}
}
Initial tests on this solution show that this would work fine, but if anyone has a better solution or a more smooth way of doing this I am all ears :).
I am new to SAP JCo I have requirement to call multiple SAP System using SAP Jco. But I am unable to connect multiple sap system at the same time......
Here is code :
package com.sap.test;
import java.util.Properties;
import com.sap.conn.jco.JCoDestination;
import com.sap.conn.jco.JCoDestinationManager;
import com.sap.conn.jco.JCoException;
import com.sap.conn.jco.JCoRepository;
import com.sap.conn.jco.ext.DestinationDataProvider;
import com.sap.conn.jco.ext.Environment;
import com.sap.utils.MyDestinationDataProvider;
import com.sap.utils.SapSystem;
public class TestMultipleSAPConnection {
public static Properties properties;
public static JCoDestination dest = null;
public static JCoRepository repos = null;
public static SapSystem system = null;
String SAP_SERVER = "SAP_SERVER";
MyDestinationDataProvider myProvider = null;
public static void main(String[] args) throws JCoException {
getConnection_CRM();
getConnection_R3();
}
public static JCoDestination getConnection_R3() {
boolean connR3_flag = true;
JCoDestination dest = null;
JCoRepository repos = null;
String SAP_SERVER = "SAP_SERVER";
Properties properties = new Properties();
SapSystem system = new SapSystem();
system.setClient("100");
system.setHost("r3devsvr.myweb.com");
system.setLanguage("en");
system.setSystemNumber("00");
system.setUser("SAP-R3-USER");
system.setPassword("init1234");
properties.setProperty("jco.client.ashost", system.getHost());
properties.setProperty("jco.client.sysnr", system.getSystemNumber());
properties.setProperty("jco.client.client", system.getClient());
properties.setProperty("jco.client.user", system.getUser());
properties.setProperty("jco.client.passwd", system.getPassword());
properties.setProperty("jco.client.lang", system.getLanguage());
System.out.println("******* Connection Parameter Set *******");
MyDestinationDataProvider myProvider = new MyDestinationDataProvider();
System.out.println("******* Destination Provider Set *******");
myProvider.changePropertiesForABAP_AS(properties);
if (!Environment.isDestinationDataProviderRegistered()) {
System.out.println("Registering Destination Provider R3");
Environment.registerDestinationDataProvider((DestinationDataProvider) myProvider);
}else{
System.out.println("Destination Provider already set..R3");
connR3_flag = false;
}
try {
dest = JCoDestinationManager.getDestination((String) SAP_SERVER);
repos = dest.getRepository();
if (repos == null) {
System.out.println("Repos is null.....");
} else {
System.out.println("Repos is not null.....");
}
System.out.println("After getting repos...");
if(connR3_flag){
System.out.println("R3 Connection Successfull...");
}
} catch (Exception ex) {
System.out.println(ex);
}
return dest;
}
public static JCoDestination getConnection_CRM() {
boolean connCRM_flag = true;
JCoDestination dest = null;
JCoRepository repos = null;
String SAP_SERVER = "SAP_SERVER";
Properties properties = new Properties();
SapSystem system = new SapSystem();
system.setClient("200");
system.setHost("crmdevsvr.myweb.com");
system.setLanguage("en");
system.setSystemNumber("00");
system.setUser("SAP-CRM-USER");
system.setPassword("init1234");
properties.setProperty("jco.client.ashost", system.getHost());
properties.setProperty("jco.client.sysnr", system.getSystemNumber());
properties.setProperty("jco.client.client", system.getClient());
properties.setProperty("jco.client.user", system.getUser());
properties.setProperty("jco.client.passwd", system.getPassword());
properties.setProperty("jco.client.lang", system.getLanguage());
System.out.println("******* Connection Parameter Set *******");
MyDestinationDataProvider myProvider = new MyDestinationDataProvider();
System.out.println("******* Destination Provider Set *******");
myProvider.changePropertiesForABAP_AS(properties);
if (!Environment.isDestinationDataProviderRegistered()) {
System.out.println("Registering Destination Provider CRM");
Environment.registerDestinationDataProvider((DestinationDataProvider) myProvider);
}else{
System.out.println("Destination Provider already set..CRM");
connCRM_flag = false;
}
try {
dest = JCoDestinationManager.getDestination((String) SAP_SERVER);
repos = dest.getRepository();
if (repos == null) {
System.out.println("Repos is null.....");
} else {
System.out.println("Repos is not null.....");
}
System.out.println("After getting repos...");
if(connCRM_flag){
System.out.println("CRM Connection Successfull...");
}
} catch (Exception ex) {
System.out.println(ex);
}
return dest;
}
}
The JCo JavaDoc documentation says:
Only one implementation of DestinationDataProvider can be registered.
For registering another implementation the infrastructure has first to
unregister the implementation that is currently registered. It is not
recommended to permanently exchange DestinationDataProvider
registrations. The one registered instance should globally manage all
destination configurations for the whole infrastructure environment.
So you have to register ONE instance of the DestinationDataProvider, this is an instance of your class MyDestinationDataProvider.
This implementation needs to manage and store ALL the different logon configurations for all your SAP systems, accessible via a distinct destination name string. A simple HashMap<String, Properties> would be a sufficient storage form for this. Add the two Properties instances with distinct destination name strings to the HashMap and return the Properties instance associated to the passed destinationName from method MyDestinationDataProvider.getDestinationProperties(String destinationName).
So you can access the desired JCoDestination instance targeting any SAP system via its specific destination name. In your example you used "SAP_SERVER" for both destination configurations which won't work. For example, use the SAP System ID (SID) as the destination name (key) instead.
If using the names from your example, then JCoDestinationManager.getDestination("CRM") would return the JCoDestination instance for system "CRM" and JCoDestinationManager.getDestination("R3") the JCoDestination for system "R3". And both can be used independently and simultaneously. That's it.
Sharing with you a solution I recently came up with for this exact problem. I discovered two different ways to implement CustomDestinationDataProvider so that I could use multiple destinations.
Something that I did that helped out with both of my different solutions was change out the method in CustomDestinationDataProvider that instantiates the MyDestinationDataProvider inner class so that instead of returning ArrayList, it returns JCoDestination. I changed the name of this method from executeSAPCall to getDestination.
The first way that I discovered that allowed me to use multiple destinations, successfully changing out destinations, was to introduce a class variable for MyDestinationDataProvider so that I could keep my instantiated version. Please note that for this solution, the CustomDestinationDataProvider class is still embedded within my java application code.
I found that this solution only worked for one application. I was not able to use this mechanism in multiple applications on the same tomcat server, but at least I was finally able to successfully switch destinations. Here is the code for CustomDestinationDataProvider.java for this first solution:
public class CustomDestinationDataProvider {
private MyDestinationDataProvider gProvider; // class version of MyDestinationDataProvider
public class MyDestinationDataProvider implements DestinationDataProvider {
private DestinationDataEventListener eL;
private HashMap<String, Properties> secureDBStorage = new HashMap<String, Properties>();
public Properties getDestinationProperties(String destinationName) {
try {
Properties p = secureDBStorage.get(destinationName);
if(p!=null) {
if(p.isEmpty())
throw new DataProviderException(DataProviderException.Reason.INVALID_CONFIGURATION, "destination configuration is incorrect", null);
return p;
}
return null;
} catch(RuntimeException re) {
System.out.println("getDestinationProperties: Exception detected!!! message = " + re.getMessage());
throw new DataProviderException(DataProviderException.Reason.INTERNAL_ERROR, re);
}
}
public void setDestinationDataEventListener(DestinationDataEventListener eventListener) {
this.eL = eventListener;
}
public boolean supportsEvents() {
return true;
}
public void changeProperties(String destName, Properties properties) {
synchronized(secureDBStorage) {
if(properties==null) {
if(secureDBStorage.remove(destName)!=null) {
eL.deleted(destName);
}
} else {
secureDBStorage.put(destName, properties);
eL.updated(destName); // create or updated
}
}
}
}
public JCoDestination getDestination(String destName, Properties connectProperties) {
MyDestinationDataProvider myProvider = new MyDestinationDataProvider();
boolean destinationDataProviderRegistered = com.sap.conn.jco.ext.Environment.isDestinationDataProviderRegistered();
if (!destinationDataProviderRegistered) {
try {
com.sap.conn.jco.ext.Environment.registerDestinationDataProvider(myProvider);
gProvider = myProvider; // save our destination data provider in the class var
} catch(IllegalStateException providerAlreadyRegisteredException) {
throw new Error(providerAlreadyRegisteredException);
}
} else {
myProvider = gProvider; // get the destination data provider from the class var.
}
myProvider.changeProperties(destName, connectProperties);
JCoDestination dest = null;
try {
dest = JCoDestinationManager.getDestination(destName);
} catch(JCoException e) {
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
}
return dest;
}
}
This is the code in my servlet class that I use to instantiate and call CustomDestinationDataProvider within my application code:
CustomDestinationDataProvider cddp = new CustomDestinationDataProvider();
SAPDAO sapDAO = new SAPDAO();
Properties p1 = getProperties("SAPSystem01");
Properties p2 = getProperties("SAPSystem02");
try {
JCoDestination dest = cddp.getDestination("SAP_R3_USERID_01", p1); // establish the first destination
sapDAO.searchEmployees(dest, searchCriteria); // call the first BAPI
dest = cddp.getDestination("SAP_R3_USERID_02", p2); // establish the second destination
sapDAO.searchAvailability(dest); // call the second BAPI
} catch (Exception e) {
e.printStackTrace();
}
Again, this solution only works within one application. If you implement this code directly into more than one application, the first app that calls this code gets the resource and the other one will error out.
The second solution that I came up with allows multiple java applications to use the CustomDestinationDataProvider class at the same time. I broke the CustomDestinationDataProvider class out of my application code and created a separate java spring application for it (not a web application) for the purpose of creating a jar. I then transformed the MyDestinationDataProvider inner class into a singleton. Here's the code for the singleton version of CustomDestinationDataProvider:
public class CustomDestinationDataProvider {
public static class MyDestinationDataProvider implements DestinationDataProvider {
////////////////////////////////////////////////////////////////////
// The following lines convert MyDestinationDataProvider into a singleton. Notice
// that the MyDestinationDataProvider class has now been declared as static.
private static MyDestinationDataProvider myDestinationDataProvider = null;
private MyDestinationDataProvider() {
}
public static MyDestinationDataProvider getInstance() {
if (myDestinationDataProvider == null) {
myDestinationDataProvider = new MyDestinationDataProvider();
}
return myDestinationDataProvider;
}
////////////////////////////////////////////////////////////////////
private DestinationDataEventListener eL;
private HashMap<String, Properties> secureDBStorage = new HashMap<String, Properties>();
public Properties getDestinationProperties(String destinationName) {
try {
Properties p = secureDBStorage.get(destinationName);
if(p!=null) {
if(p.isEmpty())
throw new DataProviderException(DataProviderException.Reason.INVALID_CONFIGURATION, "destination configuration is incorrect", null);
return p;
}
return null;
} catch(RuntimeException re) {
throw new DataProviderException(DataProviderException.Reason.INTERNAL_ERROR, re);
}
}
public void setDestinationDataEventListener(DestinationDataEventListener eventListener) {
this.eL = eventListener;
}
public boolean supportsEvents() {
return true;
}
public void changeProperties(String destName, Properties properties) {
synchronized(secureDBStorage) {
if(properties==null) {
if(secureDBStorage.remove(destName)!=null) {
eL.deleted(destName);
}
} else {
secureDBStorage.put(destName, properties);
eL.updated(destName); // create or updated
}
}
}
}
public JCoDestination getDestination(String destName, Properties connectProperties) throws Exception {
MyDestinationDataProvider myProvider = MyDestinationDataProvider.getInstance();
boolean destinationDataProviderRegistered = com.sap.conn.jco.ext.Environment.isDestinationDataProviderRegistered();
if (!destinationDataProviderRegistered) {
try {
com.sap.conn.jco.ext.Environment.registerDestinationDataProvider(myProvider);
} catch(IllegalStateException providerAlreadyRegisteredException) {
throw new Error(providerAlreadyRegisteredException);
}
}
myProvider.changeProperties(destName, connectProperties);
JCoDestination dest = null;
try {
dest = JCoDestinationManager.getDestination(destName);
} catch(JCoException ex) {
ex.printStackTrace();
throw ex;
} catch (Exception ex) {
ex.printStackTrace();
throw ex;
}
return dest;
}
}
After putting this code into the jar file application and creating the jar file (I call it JCOConnector.jar), I put the jar file on the shared library classpath of my tomcat server and restarted the tomcat server. In my case, this was /opt/tomcat/shared/lib. Check your /opt/tomcat/conf/catalina.properties file for the shared.loader line for the location of your shared library classpath. Mine looks like this:
shared.loader=\
${catalina.home}/shared/lib\*.jar,${catalina.home}/shared/lib
I also put a copy of this jar file in the "C:\Users\userid\Documents\jars" folder on my workstation so that the test application code could see the code in the jar and compile. I then referenced this copy of the jar file in my pom.xml file in both of my test applications:
<dependency>
<groupId>com.mycompany</groupId>
<artifactId>jcoconnector</artifactId>
<version>1.0</version>
<scope>system</scope>
<systemPath>C:\Users\userid\Documents\jars\JCOConnector.jar</systemPath>
</dependency>
After adding this to the pom.xml file, I right clicked on each project, selected Maven -> Update Project..., and I then right clicked again on each project and selected 'Refresh'. Something very important that I learned was to not add a copy of JCOConnector.jar directly to either of my test projects. The reason for this is because I want the code from the jar file in /opt/tomcat/shared/lib/JCOConnector.jar to be used. I then built and deployed each of my test apps to the tomcat server.
The code that calls my JCOConnector.jar shared library in my first test application looks like this:
CustomDestinationDataProvider cddp = new CustomDestinationDataProvider();
JCoDestination dest = null;
SAPDAO sapDAO = new SAPDAO();
Properties p1 = getProperties("SAPSystem01");
try {
dest = cddp.getDestination("SAP_R3_USERID_01", p1);
sapDAO.searchEmployees(dest);
} catch (Exception ex) {
ex.printStackTrace();
}
The code in my second test application that calls my JCOConnector.jar shared library looks like this:
CustomDestinationDataProvider cddp = new CustomDestinationDataProvider();
JCoDestination dest = null;
SAPDAO sapDAO = new SAPDAO();
Properties p2 = getProperties("SAPSystem02");
try {
dest = cddp.getDestination("SAP_R3_USERID_02", p2);
sapDAO.searchAvailability(dest);
} catch (Exception ex) {
ex.printStackTrace();
}
I know that I've left out a lot of the steps involved in first getting the SAP JCO 3 library installed on your workstation and server. I do hope that this helps out at least one other person of getting over the hill of trying to get multiple spring mvc java spplications talking to SAP on the same server.
I have an app where I filter messages according to some rules(existing some keywords or regexps). These rules are to be stored in .properties file(as they must be persistent). I've figured out how to read data from this file. here is the part of the code:
public class Config {
private static final Config ourInstance = new Config();
private static final CompositeConfiguration prop = new CompositeConfiguration();
public static Config getInstance() {
return ourInstance;
}
public Config(){
}
public synchronized void load() {
try {
prop.addConfiguration(new SystemConfiguration());
System.out.println("Loading /rules.properties");
final PropertiesConfiguration p = new PropertiesConfiguration();
p.setPath("/home/mikhail/bzrrep/DLP/DLPServer/src/main/resources/rules.properties");
p.load();
prop.addConfiguration(p);
} catch (ConfigurationException e) {
e.printStackTrace();
}
final int processors = prop.getInt("server.processors", 1);
// If you don't see this line - likely config name is wrong
System.out.println("Using processors:" + processors);
}
public void setKeyword(String customerId, String keyword){
}
public void setRegexp(String customerId, String regexp)
{}
}
as you see I'm going to add values to some properties. Here is the .properties file itself:
users = admin, root, guest
users.admin.keywords = admin
users.admin.regexps = test-5, test-7
users.root.keywords = root
users.root.regexps = *
users.guest.keywords = guest
users.guest.regexps =
I have a GUI for user to add keywords and regexps to this config. so, how to implement methods setKeyword and setRegexp?
The easyest way I found is to read the current values of the property to the String[], add there a new value and set property.
props.setProperty(fieldName, values);