Java entityClass的NullPointerException
我本来打算抛出这个问题，但我找到了一个解决方案，但我有一些错误，所以我提出了一个新问题，这是我的代码：Java entityClass的NullPointerException,java,spring,hibernate,jpa,spring-data,Java,Spring,Hibernate,Jpa,Spring Data,我本来打算抛出这个问题，但我找到了一个解决方案，但我有一些错误，所以我提出了一个新问题，这是我的代码： @Service public class GestionAOService { @Autowired private GenericDao<AoFollow, Integer> ao_follow_dao; @Transactional public void follow_ao(Integer idcontact , Integer idao
@Service
public class GestionAOService {
@Autowired
private GenericDao<AoFollow, Integer> ao_follow_dao;
@Transactional
public void follow_ao(Integer idcontact , Integer idao) {
ao_follow_dao.create(new AoFollow(new AppelOffre(idao) , new Contact(idcontact)));
ao_follow_dao.read(1);
}
.....
@Configuration@Repository
public class GenericDaoJpaImpl<T, PK extends Serializable>
implements GenericDao<T, PK> {
protected Class<T> entityClass;
@PersistenceContext
protected EntityManager entityManager;
public GenericDaoJpaImpl() {
}
public GenericDaoJpaImpl(Class<T> entityClass) {
this.entityClass = entityClass;
}
@Override
public T create(T t) {
this.entityManager.persist(t);
return t;
}
@Override
public T read(PK id) {
return this.entityManager.find(entityClass, id);
}
@Override
public T update(T t) {
return this.entityManager.merge(t);
}
@Override
public void delete(T t) {
t = this.entityManager.merge(t);
this.entityManager.remove(t);
}
@Override
public void delete(Set<T> ts) {
for( T t : ts){
t = this.entityManager.merge(t);
this.entityManager.remove(t);
}
}
}
@存储库
公共类GenericDaoJpaImpl
实现GenericDao{
保护类实体类；
@持久上下文
受保护的实体管理器实体管理器；
公共通用DAOJPAIMPL（）{
}
公共GenericDaoJpaImpl（类entityClass）{
this.entityClass=entityClass；
}
@凌驾
公共T创建（T）{
this.entityManager.persist（t）；
返回t；
}
@凌驾
公共T读（主键id）{
返回此.entityManager.find（entityClass，id）；
}
@凌驾
公共T更新（T）{
返回此.entityManager.merge（t）；
}
@凌驾
公共作废删除（T）{
t=this.entityManager.merge（t）；
此.entityManager.remove（t）；
}
@凌驾
公共作废删除（集合ts）{
for（T:ts）{
t=this.entityManager.merge（t）；
此.entityManager.remove（t）；
}
}
}
public interface GenericDao<T, PK extends Serializable> {
T create(T t);
T read(PK id);
T update(T t);
void delete(T t);
void delete(Set<T> ts);
}
公共接口GenericDao{
T创建（T）；
T读取（pkid）；
T更新（T）；
无效删除（T）；
作废删除（设置ts）；
}
<beans ... >
<context:property-placeholder location="persistence-mysql.properties" />
<jpa:repositories base-package="repository"/>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
...
</bean>
<bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="showSql" value="true" />
</bean>
<bean id="dataSource" class="org.apache.tomcat.dbcp.dbcp2.BasicDataSource">
...
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>
<context:component-scan base-package="service"/>
<context:component-scan base-package="dao"/>
<tx:annotation-driven transaction-manager="transactionManager" />
</beans>
...
...
java.lang.NullPointerException
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.<init>(SessionImpl.java:2508)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.<init>(SessionImpl.java:2495)
at org.hibernate.internal.SessionImpl.byId(SessionImpl.java:1043)
at org.hibernate.internal.SessionImpl.get(SessionImpl.java:955)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1110)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1068)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:262)
at com.sun.proxy.$Proxy42.find(Unknown Source)
at dao.GenericDaoJpaImpl.read(GenericDaoJpaImpl.java:46)
at service.GestionAOService.follow_ao(GestionAOService.java:88)
at service.GestionAOService$$FastClassBySpringCGLIB$$8fa00f17.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:708)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644)
at service.GestionAOService$$EnhancerBySpringCGLIB$$a32311b9.follow_ao(<generated>)
at controller.GestionAO.FollowAO(GestionAO.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
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.doGet(FrameworkServlet.java:852)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.logging.log4j.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:67)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:106)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.__invoke(StandardHostValve.java:142)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:534)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1081)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1566)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1523)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
java.lang.NullPointerException
位于org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl。（SessionImpl.java:2508）
位于org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl。（SessionImpl.java:2495）
位于org.hibernate.internal.SessionImpl.byId（SessionImpl.java:1043）
位于org.hibernate.internal.SessionImpl.get（SessionImpl.java:955）
位于org.hibernate.jpa.spi.AbstractEntityManagerImpl.find（AbstractEntityManagerImpl.java:1110）
位于org.hibernate.jpa.spi.AbstractEntityManagerImpl.find（AbstractEntityManagerImpl.java:1068）
在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）处
位于sun.reflect.NativeMethodAccessorImpl.invoke（未知源）
在sun.reflect.DelegatingMethodAccessorImpl.invoke处（未知源）
位于java.lang.reflect.Method.invoke（未知源）
位于org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke（SharedEntityManagerCreator.java:262）
位于com.sun.proxy.$Proxy42.find（未知源）
位于dao.GenericDaoJpaImpl.read（GenericDaoJpaImpl.java:46）
at service.GestionAOService.follow_ao（GestionAOService.java:88）
在service.GestionAOService$$FastClassBySpringCGLIB$$8fa00f17.invoke（）处
位于org.springframework.cglib.proxy.MethodProxy.invoke（MethodProxy.java:204）
位于org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint（CglibAopProxy.java:708）
在org.springframework.aop.framework.ReflectiveMethodInvocation.procedue（ReflectiveMethodInvocation.java:157）上
位于org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation（TransactionInterceptor.java:98）
位于org.springframework.transaction.interceptor.TransactionSpectSupport.invokeWithinTransaction（TransactionSpectSupport.java:262）
位于org.springframework.transaction.interceptor.TransactionInterceptor.invoke（TransactionInterceptor.java:95）
在org.springframework.aop.framework.ReflectiveMethodInvocation.procedue（ReflectiveMethodInvocation.java:179）上
位于org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept（CglibAopProxy.java:644）
在service.GestionAOService$$EnhancerBySpringCGLIB$$a32311b9.follow_ao（）
位于controller.GestionAO.FollowAO（GestionAO.java:64）
在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）处
位于sun.reflect.NativeMethodAccessorImpl.invoke（未知源）
在sun.reflect.DelegatingMethodAccessorImpl.invoke处（未知源）
位于java.lang.reflect.Method.invoke（未知源）
位于org.springframework.web.method.support.InvocableHandlerMethod.invoke（InvocableHandlerMethod.java:215）
位于org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest（InvocableHandlerMethod.java:132）
位于org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle（ServletInvocableHandlerMethod.java:104）
位于org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod（RequestMappingHandlerAdapter.java:749）
位于org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal（RequestMappingHandlerAdapter.java:689）
位于org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle（AbstractHandlerMethodAdapter.java:83）
位于org.springframework.web.servlet.DispatcherServlet.doDispatch（DispatcherServlet.java:938）
位于org.springframework.web.servlet.DispatcherServlet.doService（DispatcherServlet.java:870）
位于org.springframework.web.servlet.FrameworkServlet.processRequest（FrameworkServlet.java:961）
位于org.springframework.web.servlet.FrameworkServlet.doGet（FrameworkServlet.java:852）
位于javax.servlet.http.HttpServlet.service（HttpServlet.java:618）
位于org.springframework.web.servlet.FrameworkServlet.service（FrameworkServlet.java:837）
位于javax.servlet.http.HttpServlet.service（HttpServlet.java:725）
位于org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:291）
位于org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:206）
位于org.apache.tomcat.websocket.server.WsFilter.doFilter（WsFilter.java:52）
位于org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:239）
位于org.apache.catalina.core.ApplicationFilterChain
<beans ... >
<context:property-placeholder location="persistence-mysql.properties" />
<jpa:repositories base-package="repository"/>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
...
</bean>
<bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="showSql" value="true" />
</bean>
<bean id="dataSource" class="org.apache.tomcat.dbcp.dbcp2.BasicDataSource">
...
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>
<context:component-scan base-package="service"/>
<context:component-scan base-package="dao"/>
<tx:annotation-driven transaction-manager="transactionManager" />
</beans>
java.lang.NullPointerException
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.<init>(SessionImpl.java:2508)
at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.<init>(SessionImpl.java:2495)
at org.hibernate.internal.SessionImpl.byId(SessionImpl.java:1043)
at org.hibernate.internal.SessionImpl.get(SessionImpl.java:955)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1110)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:1068)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:262)
at com.sun.proxy.$Proxy42.find(Unknown Source)
at dao.GenericDaoJpaImpl.read(GenericDaoJpaImpl.java:46)
at service.GestionAOService.follow_ao(GestionAOService.java:88)
at service.GestionAOService$$FastClassBySpringCGLIB$$8fa00f17.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:708)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644)
at service.GestionAOService$$EnhancerBySpringCGLIB$$a32311b9.follow_ao(<generated>)
at controller.GestionAO.FollowAO(GestionAO.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
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.doGet(FrameworkServlet.java:852)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.logging.log4j.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:67)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:106)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.__invoke(StandardHostValve.java:142)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:534)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1081)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1566)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1523)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
@Service
@Transactional
public class GestionAOService {
...
}
<context:component-scan base-package="config"/>