Why autowiring bean is null?

Question

I write test for my application:

public class CandidateServiceTest { @Autowired CandidateService candidateService; @BeforeClass public static void initialize() throws Exception{ ApplicationContext context = new ClassPathXmlApplicationContext( "test/BeanConfig.xml");//I think here I load context UtilMethods.createTestDb(); } @Test public void add(){ Candidate candidate = new Candidate(); candidate.setName("testUser"); candidateService.add(candidate);//NullPointerException here List<Candidate> candidates = candidateService.findByName(candidate.getName()); Assert.assertNotNull(candidates); } }

in row

candidateService.add(candidate);//Null entity here here

candidateService is null.

test/BeanConfig.xml:

 <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:lang="http://www.springframework.org/schema/lang" xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:util="http://www.springframework.org/schema/util" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd"> <!-- Включаем опцию использования конфигурационных аннотаций (@Annotation-based configuration)--> <context:annotation-config /> <context:component-scan base-package="com.epam.hhsystem.jpa" /> <context:component-scan base-package="package com.epam.hhsystem.services" /> <!-- Файл с настройками ресурсов для работы с данными (Data Access Resources) --> <import resource="data.xml" /> </beans>

data.xml - info about hibernate,

class of CandidateService:

package com.epam.hhsystem.services; ... @Transactional @Service("candidateService") public class CandidateService { @Autowired private CandidateDao candidateDao;//package com.epam.hhsystem.jpa @Autowired private VacancyDao vacancyDao;//package com.epam.hhsystem.jpa @Autowired private SkillDao skillDao;//package com.epam.hhsystem.jpa @Autowired private EventDao eventDao;//package com.epam.hhsystem.jpa @Autowired UtilService utilService;//package com.epam.hhsystem.services public void add(Candidate candidate) { Authentication auth = SecurityContextHolder.getContext().getAuthentication(); String login = auth.getName(); User user = utilService.getOrSaveUser(login); candidate.setAuthor(user); candidateDao.add(candidate); } .... }

Can you help me?

UPDATE

I rewrite code so:

@ContextConfiguration(locations = {"classpath:/test/BeanConfig.xml"}) public class CandidateServiceTest extends AbstractTransactionalJUnit4SpringContextTests{ @Autowired CandidateService candidateService; @BeforeClass public static void initialize() throws Exception{ UtilMethods.createTestDb(); } @Test public void add(){ Candidate candidate = new Candidate(); candidate.setName("testUser"); candidateService.add(candidate); List<Candidate> candidates = candidateService.findByName(candidate.getName()); Assert.assertNotNull(candidates); } }

And I have so trace:

java.lang.NullPointerException at com.epam.hhsystem.services.CandidateService.add(CandidateService.java:56) at com.epam.hhsystem.services.CandidateService$$FastClassByCGLIB$$3796612d.invoke(<generated>) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:698) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150) at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:96) at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:260) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:631) at com.epam.hhsystem.services.CandidateService$$EnhancerByCGLIB$$afe33393.add(<generated>) at com.epam.hhhsystem.services.CandidateServiceTest.add(CandidateServiceTest.java:40) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74) at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83) at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:88) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71) at org.junit.runners.ParentRunner.run(ParentRunner.java:309) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Did you tell your JUnit to use Spring test runner? What annotations do you have on CandidateServiceTest? — Piotr Kołaczkowski
– Piotr Kołaczkowski, Commented Sep 23, 2013 at 16:11
Small remark regarding your config <context:annotation-config /> is already implied by using a <context:component-scan ../>. And instead of multiple <context:component-scan ../> simply use a single one with a , seperated list of packages to scan. — M. Deinum
– M. Deinum, Commented Sep 23, 2013 at 16:17
Your service assumes that there is an Authentication object, but there isn't one. You need to set one before your test starts, either in your @Test or by using a @Before method. — M. Deinum
– M. Deinum, Commented Sep 23, 2013 at 16:37

M. Deinum · Accepted Answer · 2013-09-23 16:43:45Z

Your testcase is written wrong. Use the framework don't work around it. Use Springs Test Support classes to load and autowire your testcase, instead of trying to work your way around it.

@ContextConfiguration(locations = {"classpath:/test/BeanConfig.xml"}) public class CandidateServiceTest extends AbstractTransactionalJUnit4SpringContextTests { @Autowired CandidateService candidateService; @Test public void add(){ Candidate candidate = new Candidate(); candidate.setName("testUser"); candidateService.add(candidate);//NullPointerException here List<Candidate> candidates = candidateService.findByName(candidate.getName()); Assert.assertNotNull(candidates); } }

I strongly suggest a read of the Spring Reference Guide and in this case especially the section covering testing.

Next to not using the framework properly you aren't setting your initial state properly. You are writing a unit/integration test and your CandidateService implementation expects that a Spring Security Authentication object is available. You aren't setting one before your test is run so that will result in a NullPointerException.

Add a @Before method which will set it before your test method and an @After method which cleans up after that. (Or do it in your test method but remember to cleanup properly!).

@Before public void setup() { TestingAuthenticationToken testToken = new TestingAuthenticationToken("testUser", ""); SecurityContextHolder.getContext().setAuthentication(testToken); } @After public void cleanUp { SecurityContextHolder.clearContext(); }

AbstractTransactionalJUnit4SpringContextTest - can you write maven dependency ?
I would say there is a mistake here: <context:component-scan base-package="package com.epam.hhsystem.services" />. It should not have "package" in there.
Can you explain how Did you ubderstand problem with spring security?

Casper Ngo · Accepted Answer · 2013-09-23 16:54:17Z

I don't see the annotation for test class that you put here. Normally, to run test class in Spring context, you need to use following annotation:

@RunWith(SpringJUnit4ClassRunner.class) // This will run necessary job to load the context and inject bean into your test @ContextConfiguration("classpath:/test-bundle-context.xml") // This specify the configuration used, you can use the java-config style as well (but only for Spring 3.1) @TransactionConfiguration(transactionManager = "txManager", defaultRollback = true) // If you want to test the transaction, otherwise, this is not necessary @Transactional(propagation = Propagation.SUPPORTS) // depend on your test natural, you can set difference propagation.

Component scan doesn't help anything in your test.

Maven dependency:

<dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>3.1.0.RELEASE</version> <scope>test</scope> </dependency>

It should be the same as Deinum mentioned, see my answer edited above

Ernestas Kardzys · Accepted Answer · 2013-09-24 05:43:14Z

I guess your BeanConfig.xml is wrong, because it contains "package":

 <context:component-scan base-package="package com.epam.hhsystem.services" />

Change it to:

// package removed <context:component-scan base-package="com.epam.hhsystem.services" />

Does it help?

Alex R · Accepted Answer · 2016-10-16 17:47:49Z

I was having a similar problem and the cause turned out to be none of the answers above. Turns out my IDE had inserted import org.junit.Test instead of import org.testng.annotations.Test. Trivial but very hard to track down.

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