How do I make Autowired work inside a Configuration class? - java

I'm trying to autowire an attribute (myService) which is tagged as a #Service, inside a #Configuration class, but I get a NullPointer.
If instead, I autowire myService in non-configuration classes, I have no issues.
Here's the #Service I'm having issues autowiring:
package com.myapp.resources;
#Service
class MyService {
public List<String> getRoutingKeys() {
List<String> routingKeys;
//Do stuff
return routingKeys;
}
public String aMethod() {
return "hello";
}
}
Here's the #Configuration class where I can't autowire the Service
package com.myapp.messaging;
import com.myapp.resources;
import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.Queue;
import org.springframework.amqp.core.TopicExchange;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.util.List;
#Configuration
public class RabbitConfiguration {
private List<String> routingKeys = writeRoutingKeys();
#Autowired
private MyService myService;
private List<String> writeRoutingKeys() {
boolean test = myService == null;
System.out.println("is the service null? " + test); //output: true!!!
return myService.getRoutingKeys(); //here I get a NullPointer
}
//Methods with bean declarations for RabbitMQ
}
If it helps, here's my mainclass:
package com.myapp;
import com.myapp.resources;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
import java.util.List;
#SpringBootApplication
public class Application {
public static void main(String[] args) {
ConfigurableApplicationContext appContext = SpringApplication.run(Application.class, args);
MyService myService = (MyService) appContext.getBean(MyService.class);
boolean test = myService == null;
System.out.println("is the service null? " + test); //output: false
//Do stuff
}
}
If it helps, here's a different class (a #RestController) where I'm able to autowire the service
package com.myapp.resources;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
#RestController
public class MyController {
#Autowired
private MyService myService;
#GetMapping("/endpoint")
public String myRestMethod() {
boolean test = myService == null;
System.out.println("is the service null? " + test); //output: false
return myService.aMethod();
}
}
I've also tried adding the #ComponentScan in the Configuration class, but I still get a NullPointer
package com.myapp.messaging;
//list of imports...
#Configuration
#ComponentScan("com.myapp.demo")
public class RabbitConfiguration {
#Autowired
private MyService myService;
//...
}

Spring will only inject the dependencies after or when a bean is instantiated (Depending if constructor injection is used or not). However , you are now accessing the dependency MyService during the field initialisation which happens before initialising a bean .Hence , it cannot access MyService during field initialisation as it is not injected yet.
You can simply fix it by changing to use constructor injection and initialise routingKeys inside a constructor at the same time :
#Configuration
public class RabbitConfiguration {
private List<String> routingKeys ;
private MyService myService;
#Autowired
public RabbitConfiguration(MyService myService){
this.myService = myService
this.routingKeys = writeRoutingKeys();
}
private List<String> writeRoutingKeys() {
return myService.getRoutingKeys();
}
}
Or simply :
#Autowired
public RabbitConfiguration(MyService myService){
this.myService = myService
this.routingKeys = myService.getRoutingKeys();
}

I would suggest injecting the service through any #Bean creation method that needs it:
#Bean
public MyBean create(MyService myService)
and then pass the service into the writeRoutingKeys(MyService myService) method to process it accordingly.
Per documentation:
#Configuration classes are processed quite early during the
initialization of the context and forcing a dependency to be injected
this way may lead to unexpected early initialization. Whenever
possible, resort to parameter-based injection as in the example above.

Related

Loading a random class using reflection and have it register as a component in springboot

I have a random class in a random package that is loaded through reflection after the app launches, is there a way for it to be registered as a component under springboot and have annotations such as #Autowired and #Value etc work for that class.
It works when it is in the same package at launch time, but if introduce it thorough another jar at runtime (same package or not) it doesn't work.
Below are samples that don't work even if it is in the same jar. I can't change the app's configuration - it would defeat the "random package/random class" objective.
Code in Spring boot application package
package sample.app
#SpringBootApplication
public class Application {
public static void main(String[] args) {
// Code that starts app
//
//
try {
Thread.sleep(7000);
Class test = Class.forName("test.Test", true, Application.class.getClassLoader());
System.out.println(test.getMethod("getName").invoke(null)); //NPE
System.out.println(test.getMethod("getProfiles").invoke(null)); //NPE
} catch (Throwable t) {
t.printStackTrace();
}
}
}
Test.java
package test;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.DependsOn;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Map;
#DependsOn("blaaaaaaaah")
#ComponentScan
public class Test {
#DependsOn("blaaaaaaaah")
public static String getName() {
return SpringGetter.instance.getApplicationName();
}
#DependsOn("blaaaaaaaah")
public static String[] getProfiles() {
String[] profiles = SpringGetter.instance.getEnv().getActiveProfiles();
if (profiles == null || profiles.length == 0) {
profiles = SpringGetter.instance.getEnv().getDefaultProfiles();
}
return profiles;
}
}
SpringGetter.java
package test;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
#Component("blaaaaaaaah")
public class SpringGetter implements InitializingBean {
public static SpringGetter instance;
#Value("${spring.application.name}")
private String applicationName;
#Autowired
private Environment env;
public SpringGetter() {
System.out.println("consASFJEFWEFJWDNFWJVNJSBVJWNCJWBVJNVJNVJSNJSNCSDJVNSVJtruct");
}
public String getApplicationName() {
return applicationName;
}
public void setApplicationName(String applicationName) {
this.applicationName = applicationName;
}
public Environment getEnv() {
return env;
}
public void setEnv(Environment env) {
this.env = env;
}
#PostConstruct
public void setInstance() {
instance = this;
}
#Override
public void afterPropertiesSet() throws Exception {
instance = this;
}
}
EDIT:
I managed to dynamically create the SpringGetter class as part of the same package as the Application class(the one with the #SpringBootApplication). I got Test.java to point to that dynamic class and yet no luck.
To simply inject fields into a POJO as if it were a Spring-managed bean, you can use something like the following:
#Component
public class BeanInitializer implements ApplicationContextAware {
private AutowireCapableBeanFactory beanFactory;
#Override
public void setApplicationContext(final ApplicationContext applicationContext) {
beanFactory = applicationContext.getAutowireCapableBeanFactory();
}
public void initializeObject(Object pojo) {
beanFactory.autowireBean(pojo);
}
}
Note, however, that this only injects fields marked as #Autowired or #Injected. It does not create proxies that honor method interception strategies based on e.g. #Transactional, #Async, etc.
If you're using Spring 5, have a look at the registerBean() method from GenericApplicationContext. You can find an example here: https://www.baeldung.com/spring-5-functional-beans
The issue in your Test class may also be that you're not loading the Spring Boot context from the main class. You can use the SpringBootTest annotation for this.

Create #MockBean with qualifier by annotating class?

In my Spring Boot test I'm using 2 mock beans with different qualifiers:
#RunWith(SpringRunner.class)
#SpringBootTest
class HohoTest {
#MockBean #Qualifier("haha") IHaha ahaha;
#MockBean #Qualifier("hoho") IHaha ohoho;
}
Since I'm not using these beans explicitly, I would rather move them away from the class body, as the #MockBean annotation is now repeatable:
#RunWith(SpringRunner.class)
#SpringBootTest
#MockBean(IHaha.class)
#MockBean(IHaha.class)
class HohoTest {}
However, I need to pass in a qualifier as well, since they have the same type. Any idea on how I can achieve that?
Because using annotation #Qualifier means choose bean by name, so you can set up a name for a mock with code like this:
#ExtendWith(SpringExtension.class)
#ContextConfiguration(classes = {JsonMapperConfig.class})
public class IntegrationFlowTest {
#MockBean(name = "s3MessageRepository")
private S3Repository s3MessageRepository;
// etc
If it is okay to move the mock definition completely out of the test class, you could also create the mocks in a separate #Configuration class:
#Configuration
public class MockConfiguration
{
#Bean #Qualifier("haha")
public IHaha ahaha() {
return Mockito.mock(IHaha.class);
}
#Bean #Qualifier("hoho")
public IHaha ohoho() {
return Mockito.mock(IHaha.class);
}
}
When declaring #MockBean at the class level, there is currently no support for providing a qualifier.
If you would like to have such support, I suggest you request it in the Spring Boot issue tracker.
Otherwise, you will need to continue declaring #MockBean on fields alongside #Qualifier.
I had a similar requirement of injecting mocked service beans with #Order annotation. I also needed to verify the invocation count of service functions. Below is my implementation. It might help someone.
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;
import org.springframework.test.context.junit4.SpringRunner;
#RunWith(SpringRunner.class)
#SpringBootTest
public class ServiceNameTest {
#Autowired private ServiceName serviceName;
// Important: Used to reset interaction count of our static
// bean objects before every test.
#Before
public void reset_mockito_interactions() {
Mockito.clearInvocations(MockServicesConfig.bean1);
Mockito.clearInvocations(MockServicesConfig.bean2);
}
#Configuration
public static class MockServicesConfig {
public static InterfaceName bean1;
public static InterfaceName bean2;
#Bean
#Order(1)
public InterfaceName bean1() {
bean1 = Mockito.mock(InterfaceName.class);
// Common when() stubbing
return bean1;
}
#Bean
#Order(2)
public InterfaceName vmpAdapter() {
bean2 = Mockito.mock(InterfaceName.class);
// Common when() stubbing
return bean2;
}
}
#Test
public void test_functionName_mock_invocation1() {
// Arrange --> Act --> Assert
// nullify other functions custom when() stub.
// updating this functions custom when() stub.
verify(MockServicesConfig.bean1, times(1)).functionName("");
}
#Test
public void test_functionName_mock_invocation2() {
// Arrange --> Act --> Assert
// nullify other functions custom when() stub.
// updating this functions custom when() stub.
verify(MockServicesConfig.bean1, times(1)).functionName("");
}
}
This should now work
#SpringBootTest(
classes = Some.class
)
#MockBean(name = BEAN_NAME, classes = TheBeanClass.class)
#MockBean(name = BEAN_NAME_2, classes = TheBeanClass.class)
class SomeTest {
private final Some some;
#Autowired
SomeTest(Some some) {
this.some = some;
}
}
Please note, if you need to use any of the mocked beans, you will have to put the #Qualifier in the constructor, for example
private final TheBeanClass theBeanclass;
private final Some some;
#Autowired
SomeTest(Some some, #Qualifier(BEAN_NAME) TheBeanClass theBeanClass) {
this.some = some;
this.theBeanClass = theBeanClass;
}

Spring test service class mocking utility class- Junit and Mockito

I want to write test cases for service layer of spring framework using Junit + Mockito.
How to call the actual service layer method using my ServiceTest class, If i mock the ServiceTest class then it's object wont execute the actual service method code because it wont get the object to call it's methods and if I try with the Spy still it was not working, I tried this example
still I not able to execute the test cases.
MyService.java
#Service
public class MyService{
#Autowired
Utility utility;
public String showResult(){
String result = utility.getName();
return result;
}
}
MyServiceTest.java
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(loader=AnnotationConfigWebContextLoader.class)
#WebAppConfiguration
public class MyServiceTest {
#Autowired
MyService myService;
#Autowired
Utility utility;
#Test
public void testShowResult() throws Exception {
assertEquals("Test",myService.showResult());
}
#Configuration
static class MykServiceTestContextConfiguration {
#Bean
public MyService myService() {
return new MyService();
}
#Bean
public Utility utility() {
return Mockito.mock(Utility.class);
}
}
}
You have to first mock the Utility class and then have to invoke it before calling your #Test using MockitoAnnotations.initMocks(this) as follows:
MyServiceTest.java
import static org.mockito.Mockito.when;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.AnnotationConfigWebContextLoader;
import org.springframework.test.context.web.WebAppConfiguration;
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(loader = AnnotationConfigWebContextLoader.class)
#WebAppConfiguration
public class MyServiceTest {
#InjectMocks
private MyService myService;
#Mock
private Utility utility;
#Before
public void setupMock() {
MockitoAnnotations.initMocks(this);
}
#Test
public void testShowResult() throws Exception {
when(utility.getName()).thenReturn("Test");
Assert.assertEquals("Test", myService.showResult());
}
#Configuration
static class MykServiceTestContextConfiguration {
#Bean
public MyService myService() {
return new MyService();
}
#Bean
public Utility utility() {
return new Utility();
}
}
}
MyService.java
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
#Service
public class MyService {
#Autowired
private Utility utility;
public String showResult() {
String result = utility.getName();
return result;
}
}
Utility.java
import org.springframework.stereotype.Component;
#Component
public class Utility {
public String getName() {
return "hello";
}
}
Make use of #Spy
When spy is called, then actual method of real object is called.
https://www.tutorialspoint.com/mockito/mockito_spying.htm
please go through the tutorial
This worked for me
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration
#WebAppConfiguration
public class MyServiceTest {
#Spy
MyService myService;
#Test
public void testShowResult() throws Exception {
assertEquals("Test",myService.showResult());
}
#Service
public class MyService{
public String showResult(){
return "Test";
}
}
}
still having issues share the spring version you are using
How about using #MockBean? It suits Spring + JUnit and, probably you need to implement mock behavior.
I guess that Utility.getName() return "Test" in the test case.
The following is the test code I tried.
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(loader = AnnotationConfigWebContextLoader.class)
#WebAppConfiguration
public class MyServiceTest {
#Autowired
MyService myService;
#MockBean
Utility utility;
#Test
public void testShowResult() throws Exception {
Mockito.when(utility.getName()).thenReturn("Test");
assertEquals("Test", myService.showResult());
}
#Configuration
static class MykServiceTestContextConfiguration {
#Bean
public MyService myService() {
return new MyService();
}
}
}

Nullpointer when using #Autowire

I want to create a DAO object by dependency injection (#Autowire) but unfortunately, this DAO object is never created and hence a Nullpointer exception is thrown.
This is my DAO implementation:
package com.sample.dao.service;
#Component
public class OrderServiceImpl implements OrderService {
private final OrderRepository orderRepository;
#Autowired
OrderServiceImpl(OrderRepository orderRepository) {
this.orderRepository = orderRepository;
}
#Override
public void save(Order order) {
return orderRepository.save(order);
}
The class where the Nullpointer exception is caused:
package com.sample.dispatcher;
#Component
public class OrderDispatcher {
private final OrderServiceImpl orderServiceImpl;
#Autowired
public OrderDispatcher(OrderServiceImpl orderServiceImpl) {
this.orderServiceImpl = orderServiceImpl;
}
public void createOrder(Order order) {
orderServiceImpl.save(order)); // --> Nullpointer
My entry class:
package com.sample;
#SpringBootApplication
#ComponentScan(basePackages = { "com.sample" , "com.webservice"})
#EnableJpaRepositories(basePackages = "com.sample.dao.repository")
public class Application {
public static void main(final String[] args) {
SpringApplication.run(Application.class, args);
I think you should change your constructor to have an argument type of interface rather than a concrete implementation. So something like this -
#Component
public class OrderDispatcher {
private final OrderService orderServiceImpl;
#Autowired
public OrderDispatcher(OrderService orderServiceImpl) {
this.orderServiceImpl = orderServiceImpl;
}
When you add the #component notation on OrderServiceImpl, Spring creates proxy for that class and it can be autowired by interface.
Maybe you forgot the #annotation configuration. Try adding this class and also you scan your entities: EntityScan
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
#Configuration
#EntityScan("com.sample.model") // Your model package
#ComponentScan(basePackages = { "com.sample" , "com.webservice"})
#EnableJpaRepositories(basePackages = "com.sample.dao.repository")
public class RepositoryConfig {
}

Autowire in An Nonbean Class using AspectJ

AppConfig contains Java Configuration.
package com.wh;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableLoadTimeWeaving;
import org.springframework.context.annotation.EnableLoadTimeWeaving.AspectJWeaving;
import org.springframework.context.annotation.Lazy;
import org.springframework.context.annotation.aspectj.EnableSpringConfigured;
#Configuration
#EnableSpringConfigured
#EnableLoadTimeWeaving(aspectjWeaving=AspectJWeaving.ENABLED)
public class AppConfig {
#Bean
#Lazy
public EchoService echoService(){
return new EchoService();
}
#Bean
public InstrumentationLoadTimeWeaver loadTimeWeaver() throws Throwable {
InstrumentationLoadTimeWeaver loadTimeWeaver = new InstrumentationLoadTimeWeaver();
return loadTimeWeaver;
}
}
Service Class
package com.wh;
import org.springframework.stereotype.Service;
#Service
public class EchoService {
public void echo( String s ) {
System.out.println( s );
}
}
EchoDelegateService is the Non Bean class in which we have Autowired The required Bean.
We expect that the EchoService should get autowired.
Problem : EchoService not getting autowired. Gives an Null Pointer exception.
package com.wh;
import org.springframework.beans.factory.annotation.Autowire;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Configurable;
#Configurable( preConstruction = true, autowire = Autowire.BY_TYPE, dependencyCheck = false )
public class EchoDelegateService {
#Autowired
private EchoService echoService;
public void echo( String s ) {
echoService.echo( s );
}
}
Main Class where we are calling method of NonBean Class.
package com.wh;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class MainApp {
public static void main(String[] args) {
ApplicationContext ctx =
new AnnotationConfigApplicationContext(AppConfig.class);
new EchoDelegateService().echo("hihi, it works...");
}
}
Your question already includes the answer: "... in a non-bean class". This simply does not work. All the autowiring, aspect resolving and whatever is to that, only works for beans. Thus, you definitely need to construct your EchoDelegateService via the spring factory:
EchoDelegateService myService = ctx.getBean(EchoDelegateService.class);
myService.echo("this should really work now");

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