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i have some problem with my constructor in one my controller. I try to call one service in a constructor. The Service is autowired in an AbstractController, but i got a nullpointer exception.
A component:
@Component
@RestController
@RequestMapping(value = "/test", ...)
public class AController extends AbstractController {
@Autowired
SomeService someService;
public AController(){
globalService.setClazz(Test.class);
}
....
here the AbstractController:
public abstract class AbstractController<T> {
@Autowired
GlobalService globalService;
...
here the exception. It is throwed in by globalService.setClazz(Test.class);
Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.x.server.controller.AController]: Constructor threw exception; nested exception is java.lang.NullPointerException -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:1.3.1.RELEASE:run (default-cli) on project eza: An exception occurred while running. null
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:216)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:862)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:286)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:197)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.MojoExecutionException: An exception occurred while running. null
at org.springframework.boot.maven.AbstractRunMojo$IsolatedThreadGroup.rethrowUncaughtException(AbstractRunMojo.java:438)
at org.springframework.boot.maven.RunMojo.runWithMavenJvm(RunMojo.java:61)
at org.springframework.boot.maven.AbstractRunMojo.run(AbstractRunMojo.java:215)
at org.springframework.boot.maven.AbstractRunMojo.execute(AbstractRunMojo.java:174)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
... 20 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:467)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'movieController' defined in file [...com/x/server/controller/AController.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.x.server.controller.AController]: Constructor threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1105)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1050)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:764)
at org.springframework.boot.SpringApplication.doRun(SpringApplication.java:357)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:305)
at org.springframework.boot.builder.SpringApplicationBuilder.run(SpringApplicationBuilder.java:134)
at com.x.server.Application.main(Application.java:36)
... 6 more
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.x.server.controller.AController]: Constructor threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:163)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1098)
... 22 more
Caused by: java.lang.NullPointerException
at com.x.server.controller.AController.<init>(AController.java:40)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:147)
... 24 more
Thanks for helping
432
public class BeanInstantiationException extends FatalBeanException. Exception thrown when instantiation of a bean failed. Carries the offending bean class.
To diagnose this type of issue, we'll first make sure the bean is declared: either in an XML configuration file using the <bean /> element. or in a Java @Configuration class via the @Bean annotation. or is annotated with @Component, @Repository, @Service, @Controller, and classpath scanning is active for that package.
The best solution is to properly isolate beans. The DispatcherServlet is responsible for routing and handling requests so all related beans should go into its context. The ContextLoaderListener , which loads the root context, should initialize any beans the rest of your application needs: services, repositories, etc.
Here, @Bean instantiates two beans with ids the same as the method names and registers them within the BeanFactory (Spring container) interface. Next, we can initialize the Spring container and request any of the beans from the Spring container. This strategy also makes it simple to achieve dependency injection.
You are using globalService field inside the constructor, but the constructor is called before any @Autowired fields are set, so globalService is null at that point.
You should probably use
@PostConstruct
public void init() {
globalService.setClazz(Test.class);
}
instead of the constructor. Or better, do this setup at the same place where GlobalService is created.
96
Put the @Component annotation in your super class as well. These annotations deal with the class they are applied to and does not affect their parent class. So the @Autowiredhas no effect in the parent class
36
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