MyBatis가있는 Java Mapper에서 NullPointerException이 발생했습니다.

Question

NullPointerException이 발생하며 실수가 어디인지 알 수 없습니다.

오류는 selectByExample 기능입니다. 코드는 다음과 같습니다

package com.service.test; 

@Service 
public class TestService { 
[...] 
@Autowired 
private TestMapper TestMapper; 
[...] 

public List<Short> test(){ 
    List<Short> lista = new ArrayList<Short>(); 

    testExample me = new testExample(); 
    me.or().andTestEqualTo(1); 
    List<test> listTest = TestMapper.selectByExample(me); //line 81 

    for(int i=0; i<listTest.size(); i++){ 
     lista.add(listTest.get(i).getNuovoDb()); 
    } 

    return lista; 
} 

Controller.java

TestService ms = new TestService(); 
    List<Short> listTest = ms.sediMigrate(); //line 46 

ApplicationContext를하는 후속 :

[11/07/14 11.19.33:848 CEST] 0000004f servlet E com.ibm.ws.webcontainer.servlet.ServletWrapper service SRVE0068E: Generata eccezione non rilevata in uno dei metodi di servizio del servlet dispatcher nell'applicazione TestEAR. Creata eccezione: org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:973) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863) at javax.servlet.http.HttpServlet.service(HttpServlet.java:738) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) at javax.servlet.http.HttpServlet.service(HttpServlet.java:831) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1657) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:939) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502) at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:181) at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:3935) at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:276) at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:931) at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1592) at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:186) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:452) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:511) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:305) at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:83) at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165) at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217) at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161) at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138) at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204) at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775) at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905) at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1613) Caused by: java.lang.NullPointerException at com.service.test.TestService.test(TestService.java:81) at com.test.controller.ReturnPage(controller.java:46) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:600) at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:175) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:446) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:434) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) ... 25 more

[11/07/14 11.19.33:856 CEST] 0000004f FfdcProvider W com.ibm.ws.ffdc.impl.FfdcProvider logIncident FFDC1003I: Emesso evento FFDC in C:\Program Files\IBM\WebSphere\AppServer\profiles\AppSrv01\logs\ffdc\server1_5e0b5e0b_14.07.11_11.19.33.8537970037945028520402.txt com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest() 309 [11/07/14 11.19.33:857 CEST] 0000004f webapp E com.ibm.ws.webcontainer.webapp.WebApp logServletError SRVE0293E: [Errore servlet]-[dispatcher]: java.lang.NullPointerException at com.service.test.TestService.test(TestService.java:81) at com.test.controller.ReturnPage(controller.java:46) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:600) at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:175) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:446) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:434) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863) at javax.servlet.http.HttpServlet.service(HttpServlet.java:738) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) at javax.servlet.http.HttpServlet.service(HttpServlet.java:831) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1657) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:939) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:502) at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:181) at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:3935) at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:276) at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:931) at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1592) at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:186) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:452) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:511) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:305) at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:83) at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165) at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217) at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161) at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138) at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204) at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775) at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905) at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1613)

Answer 1

사용으로 : 여기

 <!-- enable autowire --> 
    <context:annotation-config /> 
    <context:component-scan base-package="com.service.test"/> 
[...] 


    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> 
     <property name="basePackage" value="com.test.**"/> 
     <property name="sqlSessionFactoryBeanName" value="exSqlSessionFactory"/> 
    </bean> 

오류가 봄은 명시 적으로 피해야합니다. 귀하의 콩 만들기 (new 연산자 사용) - 프레임 워크가 당신을 위해 그것을해야합니다. 그리고 빈 인스턴스는 이미 Spring 컨텍스트에 있어야합니다. new으로 서비스 빈을 인스턴스화하면 아무 것도 자동으로 실행되지 않습니다. 왜 매퍼 인스턴스 대신 null이 될 것입니다. 컨트롤러에

Autowiring은 TestService이 문제를 해결할 수 있습니다

http://docs.spring.io/spring/docs/3.0.x/reference/beans.html#beans-factory-collaborators

업데이트 봄 애플리케이션에서 정보를 의존성 주입과 콩의 라이프 사이클에 대한 봄 설명서를보고하십시오.

@Controller 
public class Controller { 
    @Autowired private TestService testService; 
    ... 
    @RequestMapping 
    public String returnPage() { 
     ... 
     testService.sediMigrate(); 
     ... 
    } 
}