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In Spring Boot which class would be initialize first #Component or #Configuration

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
}

Register BeanFactory in SpringBoot

First I'm not sure if it's a good idea to do all this.
Goal is to create some interfaces with annotations to hide legacy position based string access out of a configuration database, without implementing each interface.
Declarative configured Interface:
public interface LegacyConfigItem extends ConfigDbAccess{
#Subfield(length=3)
String BWHG();
#Subfield(start = 3, length=1)
int BNKST();
#Subfield(start = 4, length=1)
int BEINH();
:
}
Base interface for runtime identification
public interface ConfigDbAccess{
}
Dummy implementation without functionality, may change.
public class EmptyImpl {
}
Beanfactory and MethodInvocation interceptor, to handle the unimplemented methods.
#Component
public class InterfaceBeanFactory extends DefaultListableBeanFactory {
protected static final int TEXT_MAX = 400;
#Autowired
private EntityRepo entityRepo;
public <T> T getInstance(Class<T> legacyInterface, String key) {
ProxyFactory factory = new ProxyFactory(new EmptyImpl());
factory.setInterfaces(legacyInterface);
factory.setExposeProxy(true);
factory.addAdvice(new MethodInterceptor() {
#Override
public Object invoke(MethodInvocation invocation) throws Throwable {
KEY keyAnnotation = invocation.getThis().getClass().getAnnotation(Key.class);
String key= keyAnnotation.key().toUpperCase();
String ptart = invocation.getMethod().getDeclaringClass().getSimpleName();
Vpt result = entityRepo.getOne(new EntityId(ptart.toUpperCase(), schl.toUpperCase()));
Subfield sub = invocation.getMethod().getAnnotation(Subfield.class);
//TODO: Raise missing Subfield annotation
int start = sub.start();
int length = sub.length();
if (start + length > TEXT_MAX) {
//TODO: Raise invalid Subfield config
}
String value = result.getTextField().substring(start,start+length);
return value;
}
});
return (T) factory.getProxy();
}
#Override
protected Map<String, Object> findAutowireCandidates(String beanName, Class<?> requiredType, DependencyDescriptor descriptor) {
Map<String, Object> map = super.findAutowireCandidates(beanName, requiredType, descriptor);
if (ConfigDbAccess.class.isAssignableFrom(requiredType )) {
:
#SpringBootApplication
public class JpaDemoApplication {
#Autowired
private ApplicationContext context;
public static void main(String[] args) {
SpringApplication app = new SpringApplication(JpaDemoApplication.class);
// app.setApplicationContextClass(InterfaceInjectionContext .class);
app.run(args);
}
public class InterfaceInjectionContext extends AnnotationConfigApplicationContext {
public VptInjectionContext () {
super (new InterfaceBeanFactory ());
}
}
So far I got all this stuff working, except when I try to set the applications Context class to my DefaultListableBeanFactory, I'm killing the Spring boot starter web. The application starts, injects the the Autowired fields with my intercepted pseudo implementaition --- and ends.
I think I'm doing something wrong with registering the DefaultListableBeanFactory, but I've no idea how to do it right.

To get this answered:
M. Deinum pointed me to a much simpler solution:
Instead of creating a BeanFactory I installed a BeanPostProcessor with this functioniality.
#RestController
public class DemoRestController {
#Autowired
VptService vptService;
#ConfigItem(key="KS001")
private PrgmParm prgmKs001;
#ConfigItem(key="KS002")
private PrgmParm prgmKs002;
public DemoRestController() {
super();
}
Where the ConfigItem annotation defines the injection point.
Next I created a CustomBeanPostProcessor which scans all incoming beans for
fields having a ConfigItem annotation
#Component
public class CustomBeanPostProcessor implements BeanPostProcessor {
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
for (Field field : bean.getClass().getDeclaredFields()) {
SHL cfgDef = field.getAnnotation(ConfigItem.class);
if (cfgDef != null) {
Object instance = getlInstance(field.getType(), cfgDef.key());
boolean accessible = field.isAccessible();
field.setAccessible(true);
try {
field.set(bean, instance);
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
field.setAccessible(accessible);
}
}
return bean;
}
The getInstnce(field.getType(),cfgDef.key()) creates a proxy with the MethodInterceptor, which does the work.
There are a lot of things to finalize, but all in all it looks good to me.

How to mock object creation for a singleton factory?

The example I tried to follow:
#PrepareForTest(X.class)
public class XTest extends PowerMockTestCase {
#Test
public void test() {
whenNew(MyClass.class).withNoArguments().thenThrow(new IOException("error message"));
X x = new X();
x.y(); // y is the method doing "new MyClass()"
..
}
}
The factory class I am trying to unit test:
public final class LoadableBeanFactory implements ILoadableBeanFactory {
private static final class Loader {
private static final LoadableBeanFactory INSTANCE = new LoadableBeanFactory();
}
private LoadableBeanFactory() { }
public static #Nonnull LoadableBeanFactory getInstance() {
return Loader.INSTANCE;
}
public final #Nonnull <BeanT extends ILoadableBean> BeanT create(final Class<BeanT> beanClass) {
final BeanT optionBean;
try {
final Constructor<BeanT> ctor = beanClass.getConstructor();
optionBean = ctor.newInstance();
return beanClass.cast(optionBean);
} catch(Exception e) {
throw new IllegalArgumentException("Could not instantiate an instance of " + beanClass);
}
}
}
My test is below. The factory does not return the mock. I am thinking that this is because the factory is a singleton that is instantiated and loaded with a private static loader class. So, is there a way to mock this object creation scenario or should I just give up on making this into a true unit test?
#PrepareForTest(LoadableBeanFactory.class)
#Test(groups = {"FactoryTestGroup", "LoadableBeanFactoryTestGroup"})
public class LoadableBeanFactoryTest extends PowerMockTestCase {
#Mock LoadableBean mockBean;
public void setUp() {
MockitoAnnotations.initMocks(this);
}
#Test
public void shouldCreateBean() {
try {
PowerMockito.whenNew(LoadableBean.class).withNoArguments().thenReturn(mockBean);
LoadableBeanFactory.getInstance().create(LoadableBean.class);
assertEquals(LoadableBeanFactory.getInstance().create(LoadableBean.class), mockBean,
"LoadableBeanFactory should have return mocked bean, but did not: " + mockBean);
} catch(Exception e) {
fail("Failed to mock bean creation");
}
}
}

Why would you even want to do that?
If you wrap the factory in an abstraction (a separate class) then you can inject it via constructor and mock its create method.
public class BeanFactory {
public <BeanT extends ILoadableBean> BeanT create(final Class<BeanT> beanClass) {
return LoadableBeanFactory.getInstance().create(beanClass);
}
}
and now your class that you want to work with
public class SomeClass {
private final BeanFactory beanFactory;
public SomeClass(BeanFactory beanFactory) {
this.beanFactory= beanFactory;
}
public void doSth() {
beanFactory.create(...);
}
}
And then you don't need to have PowerMock at all and your design is really nice.

Could not inject Spring service into akka service

I have Spring service, which is actually actor, it is received info, but I cant pass it to another Spring service, because injection fails.
#Service("mailContainer")
#Scope("prototype")
#Component
public class MailContainer extends UntypedActor {
private final LoggingAdapter LOG = Logging.getLogger(getContext().system(), this);
private Mail value;
private List<Mail> mailList = new ArrayList<Mail>();
private Integer size;
#Autowired
#Qualifier("springService")
private SpringService springService;
//#Autowired
public void setSpringService(SpringService springService) {
this.springService = springService;
}
public MailContainer(Mail value) {
this.value = value;
}
#Override
public void onReceive(Object message) throws Exception {
// LOG.debug("+ MailContainer message: {} ", message);
if (message instanceof Mail) {
value = (Mail) message;
System.out.println("MailContainer get message with id " + value.getId());
System.out.println("With time " + value.getDateSend());
//getSender().tell(value, getSelf()); //heta uxarkum
//this.saveIt(value);
springService.add(value);
}
}
and second service
#Service("springService")
//#Component
#Scope("session")
public class SpringService {
private List<Mail> mailList = new ArrayList<Mail>();
public void add(Mail mail) {
System.out.println("Saving mail from Spring " +mail.getId());
mailList.add(mail);
}
public List<Mail> getMailList() {
return mailList;
}
}
Spring config, this is from akka spring example
#Configuration
//#EnableScheduling
//EnableAsync
#ComponentScan(basePackages = {"com"}, excludeFilters = {
#ComponentScan.Filter(Configuration.class)})
//#ImportResource("classpath:META-INF/spring/spring-data-context.xml")
//#EnableTransactionManagement
//#EnableMBeanExport
//#EnableWebMvc
public class CommonCoreConfig {
// the application context is needed to initialize the Akka Spring Extension
#Autowired
private ApplicationContext applicationContext;
/**
* Actor system singleton for this application.
*/
#Bean
public ActorSystem actorSystem() {
ActorSystem system = ActorSystem.create("AkkaJavaSpring");
// initialize the application context in the Akka Spring Extension
SpringExtProvider.get(system).initialize(applicationContext);
return system;
}
}
So, how I can inject just another Spring service?????????

Based on our discussions, I think it is due to the way you create the MailContainer actor. You aren't using the SpringExtProvider and instead are using Props.create directly. This means that Spring doesn't get the opportunity to perform dependency injection on your new actor.
Try changing this code:
#Override
public void preStart() throws Exception {
System.out.println("Mail collector preStart: {} ");
getContext().actorOf(Props.create(MailContainer.class, result), "one");
}
to use the the SpringExtProvider like this:
#Override
public void preStart() throws Exception {
System.out.println("Mail collector preStart: {} ");
getContext().actorOf(SpringExtProvider.get(getContext().system()).props("mailContainer"), "one");
}
This way you are asking the Spring extension to create the new actor and inject any required dependecnies.

Java - Execute a class method with a specify annotation

I have a android application, but it is not relevant.
I have a class called "Front controller" which will receive some message
through it's constructor. The message, for brievity, could be an integer.
I want somewhere else to create a new controller which will execute
a method based on the integer defined above
public class OtherController {
#MessageId("100")
public void doSomething(){
//execute this code
}
#MessageId("101")
public void doSomethingElse(){
//code
}
}
The front controller could be something like this:
public class FrontController {
private int id;
public FrontController(int id){
this.id=id;
executeProperControllerMethodBasedOnId();
}
public void executeProperControllerMethodBasedOnId(){
//code here
}
public int getId(){
return id;
}
}
So, if the Front Controller will receive the integer 100, it
will execute the method annotated with #MessageId(100). The
front controller don't know exactly the class where this method
is.
The problem which I found is that I need to register somehow
each controller class. I Spring I had #Component or #Controller
for autoloading. After each controllers are register, I need to
call the properly annotated method.
How to achieve this task? In Spring MVC, I had this system
implemented, used to match the HTTP routes. How could I implement
this in a plain java project?
Any suggestions?

Thanks to Google Reflections (hope you can integrate this in your android project.)
<dependency>
<groupId>org.reflections</groupId>
<artifactId>reflections-maven</artifactId>
<version>0.9.8</version>
</dependency>
For optimisation I've added the requirement to also annotate the class with MessageType annotation and the classes should be in the same package (org.conffusion in my example):
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.TYPE)
public #interface MessageType {
}
The OtherController looks like:
#MessageType
public class OtherController {
#MessageId(id=101)
public void method1()
{
System.out.println("executing method1");
}
#MessageId(id=102)
public void method2()
{
System.out.println("executing method2");
}
}
The implementation will look like:
public void executeProperControllerMethodBasedOnId() {
Set<Class<?>> classes = new org.reflections.Reflections("org.conffusion")
.getTypesAnnotatedWith(MessageType.class);
System.out.println("found classes " + classes.size());
for (Class<?> c : classes) {
for (Method m : c.getMethods()) {
try {
if (m.isAnnotationPresent(MessageId.class)) {
MessageId mid = m.getAnnotation(MessageId.class);
Object o = c.newInstance();
if (mid.id() == id)
m.invoke(o);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
Maybe you can optimise and build a static hashmap containing already scanned message ids.

You need to implement some of the work by yourself using reflection, I would recommend to prepare message handlers on initial phase in regards to performance. Also you possibly want to think about Singleton/Per Request controllers. Some of the ways to implement the solution:
interface MessageProcessor {
void execute() throws Exception;
}
/* Holds single instance and method to invoke */
class SingletonProcessor implements MessageProcessor {
private final Object instance;
private final Method method;
SingletonProcessor(Object instance, Method method) {
this.instance = instance;
this.method = method;
}
public void execute() throws Exception {
method.invoke(instance);
}
}
/* Create instance and invoke the method on execute */
class PerRequestProcessor implements MessageProcessor {
private final Class clazz;
private final Method method;
PerRequestProcessor(Class clazz, Method method) {
this.clazz = clazz;
this.method = method;
}
public void execute() throws Exception {
Object instance = clazz.newInstance();
method.invoke(instance);
}
}
/* Dummy controllers */
class PerRequestController {
#MessageId(1)
public void handleMessage1(){System.out.println(this + " - Message1");}
}
class SingletonController {
#MessageId(2)
public void handleMessage2(){System.out.println(this + " - Message2");}
}
class FrontController {
private static final Map<Integer, MessageProcessor> processors = new HashMap<Integer, MessageProcessor>();
static {
try {
// register your controllers
// also you can scan for annotated controllers as suggested by Conffusion
registerPerRequestController(PerRequestController.class);
registerSingletonController(SingletonController.class);
} catch (Exception e) {
throw new ExceptionInInitializerError();
}
}
private static void registerPerRequestController(Class aClass) {
for (Method m : aClass.getMethods()) {
if (m.isAnnotationPresent(MessageId.class)) {
MessageId mid = m.getAnnotation(MessageId.class);
processors.put(mid.value(), new PerRequestProcessor(aClass, m));
}
}
}
private static void registerSingletonController(Class aClass) throws Exception {
for (Method m : aClass.getMethods()) {
if (m.isAnnotationPresent(MessageId.class)) {
MessageId mid = m.getAnnotation(MessageId.class);
Object instance = aClass.newInstance();
processors.put(mid.value(), new SingletonProcessor(instance, m));
}
}
}
/* To process the message you just need to look up processor and execute */
public void processMessage(int id) throws Exception {
if (processors.containsKey(id)) {
processors.get(id).execute();
} else {
System.err.print("Processor not found for message " + id);
}
}
}