I have a configuration object that is managed by Spring. Let's call that object 'ConfigurationObject'. The configuration contained by that object I also want to make accessible, through delegation, in objects which I instantiate with the 'new' operator. Let's call these objects 'UserObject'.
Would it then be acceptable to pass the configurationObject as an argument to the constructor of the UserObject and then assign it to a regular private field that is not managed by Spring? So that I can then use the ConfigurationObject to return configuration form the UserObject. See below for the story in code.
#Configuration
public class ConfigurationObject {
private final String configItem;
public ConfigurationObject(#Value("${config.item}") final String configItem){
this.configItem = configItem;
}
public String getConfigItem() {
return configItem;
}
}
public final class UserObject {
private ConfigurationObject configurationObject;
/* other properties */
public UserObject(final ConfigurationObject configurationObject) {
this.configurationObject = configurationObject;
}
public String getConfigItem(){
return configurationObject.getConfigItem();
}
}
Best regards,
Henk
You can get Spring class using context from ApplicationInitializer:
ApplicationInitializer.getAppContext().getBean(ConfigurationObject.class);
Or create class to get Spring context using ApplicationContextAware:
#Component
public class SpringContext implements ApplicationContextAware {
private static ApplicationContext context;
public static UserService getUserService() {
return (UserService)context.getBean("userService");
}
#Override
public void setApplicationContext(ApplicationContext context) throws BeansException {
// store ApplicationContext reference to access required beans later on
SpringContext.context = context;
}
}
Yes. It is a very valid use-case. I often do it when I need to create an object which some of its properties are determined during the runtime which do not know upfront.
I would suggest creating a factory method on ConfigurationObject for creating an UserObject:
#Configuration
public class ConfigurationObject {
private final String configItem;
public ConfigurationObject(#Value("${config.item}") final String configItem){
this.configItem = configItem;
}
public String getConfigItem() {
return configItem;
}
public UserObject createUserObject(){
return new UserObject(this);
}
}
Related
I am working within an environment that changes credentials every several minutes. In order for beans that implement clients who depend on these credentials to work, the beans need to be refreshed. I decided that a good approach for that would be implementing a custom scope for it.
After looking around a bit on the documentation I found that the main method for a scope to be implemented is the get method:
public class CyberArkScope implements Scope {
private Map<String, Pair<LocalDateTime, Object>> scopedObjects = new ConcurrentHashMap<>();
private Map<String, Runnable> destructionCallbacks = new ConcurrentHashMap<>();
private Integer scopeRefresh;
public CyberArkScope(Integer scopeRefresh) {
this.scopeRefresh = scopeRefresh;
}
#Override
public Object get(String name, ObjectFactory<?> objectFactory) {
if (!scopedObjects.containsKey(name) || scopedObjects.get(name).getKey()
.isBefore(LocalDateTime.now().minusMinutes(scopeRefresh))) {
scopedObjects.put(name, Pair.of(LocalDateTime.now(), objectFactory.getObject()));
}
return scopedObjects.get(name).getValue();
}
#Override
public Object remove(String name) {
destructionCallbacks.remove(name);
return scopedObjects.remove(name);
}
#Override
public void registerDestructionCallback(String name, Runnable runnable) {
destructionCallbacks.put(name, runnable);
}
#Override
public Object resolveContextualObject(String name) {
return null;
}
#Override
public String getConversationId() {
return "CyberArk";
}
}
#Configuration
#Import(CyberArkScopeConfig.class)
public class TestConfig {
#Bean
#Scope(scopeName = "CyberArk")
public String dateString(){
return LocalDateTime.now().toString();
}
}
#RestController
public class HelloWorld {
#Autowired
private String dateString;
#RequestMapping("/")
public String index() {
return dateString;
}
}
When I debug this implemetation with a simple String scope autowired in a controller I see that the get method is only called once in the startup and never again. So this means that the bean is never again refreshed. Is there something wrong in this behaviour or is that how the get method is supposed to work?
It seems you need to also define the proxyMode which injects an AOP proxy instead of a static reference to a string. Note that the bean class cant be final. This solved it:
#Configuration
#Import(CyberArkScopeConfig.class)
public class TestConfig {
#Bean
#Scope(scopeName = "CyberArk", proxyMode=ScopedProxyMode.TARGET_CLASS)
public NonFinalString dateString(){
return new NonFinalString(LocalDateTime.now());
}
}
I am new using dependency injection. Can anyone tell me how to configure a servlet to inject a string URI pointing to a file? The method signature is the following:
#Inject
public void setCar(String value)
{
CarUri =value;
}
Thanks in advance!
You can try injecting #Named fields
// inside module
#Provides
#Named("CarURI")
public String carURI() {
return "URI";
}
#Inject
public void setCar(#Named("CarURI") String value) {
CarUri = value;
}
example:
https://www.tutorialspoint.com/guice/guice_field_injection.htm
https://www.tutorialspoint.com/guice/guice_method_injection.htm
I have a class annotated with #Component which is use to initialze application.yml config properties. Service classe is using configuration property. But sometime my Service class instance created before the Configuration class and I get null property value in service class, Its random not specific pattern.
Configuration Initializer class..
#Component
public class ConfigInitializer implements InitializingBean {
private static final Logger log = LoggerFactory.getLogger(ConfigInitializer.class);
#Autowired
ProxyConfig proxyConfig;
/*#PostConstruct
public void postConstruct(){
setProperties();
}
*/
#Override
public void afterPropertiesSet() {
setProperties();
}
private void setSystemProperties(){
log.debug("Setting properties...");
Properties props = new Properties();
props.put("PROXY_URL", proxyConfig.getProxyUrl());
props.put("PROXY_PORT", proxyConfig.getProxyPort());
System.getProperties().putAll(props);
}
}
#Component
#ConfigurationProperties(prefix = "proxy-config")
public static class ProxyConfig {
private String proxyUrl;
private String proxyPort;
public String getProxyUrl() {
return proxyUrl;
}
public void setProxyUrl(String proxyUrl) {
this.proxyUrl = proxyUrl;
}
public String getProxyPort() {
return proxyPort;
}
public void setProxyPort(String proxyPort) {
this.proxyPort = proxyPort;
}
}
Service Class..
#Service("receiverService")
public class ReceiverService {
private static final Logger logger = LoggerFactory.getLogger(ReceiverService.class);
private ExecutorService executorService = Executors.newSingleThreadExecutor();
#Autowired
public ReceiverService() {
initClient();
}
private void initClient() {
Future future = executorService.submit(new Callable(){
public Object call() throws Exception {
String value = System.getProperty("PROXY_URL"); **//Here I am getting null**
logger.info("Values : " + value);
}
});
System.out.println("future.get() = " + future.get());
}
}
Above Service class get null values String value = System.getProperty("PROXY_URL")
When I use #DependsOn annotation on Service class, it works fine.
In my little knowledge, I know Spring does not have specific order of bean creation.
I want to know If I use #Configuration instead of #Component on ConfigInitializer class like below, Will spring initialize ConfigInitializer
class before other beans ?.
#Configuration
public class ConfigInitializer implements InitializingBean {
//code here
}
I have set qualifier name from properties file as isomessage.qualifier=isoMessageMember1:
public class BankBancsConnectImpl implements BankBancsConnect{
#Autowired
#Resource(name="${isomessage.qualifier}")
private Iso8583Message iso8583Message;
public BancsConnectTransferComp getFundTransfer(IpsDcBatchDetail ipsDcBatchDetail) {
bancsxfr = iso8583Message.getFundTransfer(bancsxfr);
}
}
The value of ${isomessage.qualifier} is static as it is defined in the properties file. However i want it to be dynamic and get it's value from database based on certain condition. For instance i have multiple implementation of Iso8583Message (member wise) and has to call respective class of member id that is currently logged in. Please guide me to achieve this in the best and java spring way.
And my implementation class will look like this:
#Service("isoMessageMember1")
public class Iso8583MessageEBLImpl implements Iso8583Message{
public BancsConnectTransferComp getFundTransfer(BancsConnectTransferComp bancsxfr) throws Exception {
...
}
You can use Condition instead Qualifier if you are using Spring4+.
First, you need a ConfigDAO which read the qualifier name which you
need from database.
public class ConfigDAO {
public static String readFromDataSource() {
return " ";
}
}
Suppose there are two implemetions of Iso8583Message, you can
create two Condition objects.
IsoMessageMember1_Condition
public class IsoMessageMember1_Condition implements Condition {
#Override
public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
String qualifier = ConfigDAO.readFromDataSource();
if (qualifier.equals("IsoMessageMember1_Condition")) {
return true;
} else {
return false;
}
}
}
IsoMessageMember2_Condition
public class IsoMessageMember2_Condition implements Condition {
#Override
public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
String qualifier = ConfigDAO.readFromDataSource();
if (qualifier.equals("IsoMessageMember2_Condition")) {
return true;
} else {
return false;
}
}
}
Return different implemetion according to condition in config class.
#Configuration
public class MessageConfiguration {
#Bean(name = "iso8583Message")
#Conditional(IsoMessageMember1_Condition.class)
public Iso8583Message isoMessageMember1() {
return new Iso8583MessageEBLImpl();
}
#Bean(name = "iso8583Message")
#Conditional(IsoMessageMember2_Condition.class)
public Iso8583Message isoMessageMember2() {
return new OtherMessageEBLImpl();
}
}
Remove the #Qulifier and #Autowire annotations which you do not need anymore, you can retrieve the message from context every time you use it.
public class BankBancsConnectImpl implements BankBancsConnect{
private Iso8583Message iso8583Message;
public BancsConnectTransferComp getFundTransfer(IpsDcBatchDetail ipsDcBatchDetail) {
iso8583Message = (Iso8583Message)context.getBean("iso8583Message");
bancsxfr = iso8583Message.getFundTransfer(bancsxfr);
}
}
In spring it is possible to autowire the application context, and retrieve any bean based on its name.
For example, your interface signature similar to the below syntax
public interface Iso8583Message {
public String getFundDetails(String uniqueId);
}
and 2 different implementations follow below format
#Service("iso8583-message1")
public class Iso8583MessageImpl1 implements Iso8583Message {
#Override
public String getFundDetails(String uniqueId) {
return "Iso8583MessageImpl1 details ";
}
}
and
#Service("iso8583-message2")
public class Iso8583MessageImpl2 implements Iso8583Message {
#Override
public String getFundDetails(String uniqueId) {
return "Iso8583MessageImpl2 details ";
}
}
We can retrieve the beans as follows
public class BankBancsConnectImpl implements BankBancsConnect{
#Autowired
private ApplicationContext applicationContext;
public BancsConnectTransferComp getFundTransfer(IpsDcBatchDetail
ipsDcBatchDetail) {
//for retrieving 1st implementation
Iso8583Message iso8583Message=applicationContext.getBean("iso8583-message1", Iso8583Message.class);
//For retrieving 2nd implementation
Iso8583Message iso8583Message=applicationContext.getBean("iso8583-message2", Iso8583Message.class);
String result = iso8583Message.getFundTransfer(bancsxfr);
}
}
In this case, we can configure the bean names coming from the database instead of hard coded values("iso8583-message1","iso8583-message2").
I am not being able to make messageSource work in the Pojo classes,its throwing a nullpointerexception. However in all the other classes namely controller,service messageSource is working alright. Could someone please suggest what needs to be done ?
#Autowired
private MessageSource messageSource;
I have autowired the MessageSource using the above code snippet.
public class ProposalWiseSelectionForm implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
#Autowired
private MessageSource messageSource;
private String txtPageHierarchy="";
private String txtLineOfBusiness;
private String txtProduct;
private String btn;
private String clickedGo="N";
private List arrLineOfBusiness=new ArrayList();
private List arrProduct=new ArrayList();
#Valid
private ArrayList documentList=initiateDocumentList();
private String txtPageMode="I";
private String enableDiscardBtn="N";
private String enableInsertBtn="N";
private String isDivVisible="N";
private int numApplicationType=1;
public ProposalWiseSelectionForm() {
}
public String getTxtPageHierarchy() {
return txtPageHierarchy;
}
public void setTxtPageHierarchy(String txtPageHierarchy) {
this.txtPageHierarchy = txtPageHierarchy;
}
public String getTxtLineOfBusiness() {
return txtLineOfBusiness;
}
public void setTxtLineOfBusiness(String txtLineOfBusiness) {
this.txtLineOfBusiness = txtLineOfBusiness;
}
public String getTxtProduct() {
return txtProduct;
}
public void setTxtProduct(String txtProduct) {
this.txtProduct = txtProduct;
}
public String getBtn() {
return btn;
}
public void setBtn(String btn) {
this.btn = btn;
}
public String getClickedGo() {
return clickedGo;
}
public void setClickedGo(String clickedGo) {
this.clickedGo = clickedGo;
}
public List getArrLineOfBusiness() {
return arrLineOfBusiness;
}
public void setArrLineOfBusiness(List arrLineOfBusiness) {
this.arrLineOfBusiness = arrLineOfBusiness;
}
public List getArrProduct() {
return arrProduct;
}
public void setArrProduct(List arrProduct) {
this.arrProduct = arrProduct;
}
public void setArrProduct(ArrayList arrProduct) {
this.arrProduct = arrProduct;
}
public ArrayList getDocumentList() {
return documentList;
}
public void setDocumentList(ArrayList documentList) {
this.documentList = documentList;
}
public String getTxtPageMode() {
return txtPageMode;
}
public void setTxtPageMode(String txtPageMode) {
this.txtPageMode = txtPageMode;
}
public String getEnableDiscardBtn() {
return enableDiscardBtn;
}
public void setEnableDiscardBtn(String enableDiscardBtn) {
this.enableDiscardBtn = enableDiscardBtn;
}
public String getEnableInsertBtn() {
return enableInsertBtn;
}
public void setEnableInsertBtn(String enableInsertBtn) {
this.enableInsertBtn = enableInsertBtn;
}
public String getIsDivVisible() {
return isDivVisible;
}
public void setIsDivVisible(String isDivVisible) {
this.isDivVisible = isDivVisible;
}
public int getNumApplicationType() {
return numApplicationType;
}
public void setNumApplicationType(int numApplicationType) {
this.numApplicationType = numApplicationType;
}
}
In order to be able to use #Autowired in a class, that class has to be managed by Spring.
of
Your ProposalWiseSelectionForm class is obviously not managed by Spring and therefor messageSource is always null.
Using #Autowired MessageSource messageSource in your other classes works, because as you mention those classes are managed by Spring (as you have mentioned they are either controllers, services etc).
I am guessing that ProposalWiseSelectionForm is a DTO used to capture values from a form. The sort of class will not be a Spring bean and therefor you can't autowire stuff into it.
I suggest you either move the logic you need out of the DTO and into the controller (or some Spring managed utility) or in the extreme case that you absolutely need #Autowired in the DTO, take a look at #Configurable here and here
Try using #Component,you might be getting this issue because of the fact the Pojo class is not being recognized.
You have to make your class a Spring bean
Add #Component annotation to your class and add these 2 lines to your appContext.xml:
<context:component-scan base-package="com.<your-company-name>" />
<context:annotation-config />
Or just add the service in your beans section in the appContext.xml if you wish not to work with Spring component-scan feature.