Question

问题定义：

USER_TABLE和USER_DETAIL_TABLE是使用userid字段映射的OneToOne。面对两个问题！

在保存UserDetailTable时遇到nullpointer异常。
- 首先设置UserTable，然后保存USerDetailTable。
userid值生成为0，但我使用nullable = false。 - 有时我看到USER_TABLE的userid值为1，USER_DETAIL_TABLE的userid值为0.特别是当我已经为＆＃39; admin＆＃39;在创建表时。
我想要默认＆＃39; admin＆＃39;在创建数据库时插入的userid。

我正在使用以下网站提供的布局 http://websystique.com/springmvc/spring-4-mvc-and-hibernate4-integration-example-using-annotations/

使用上面示例中的AppInitializer，AppConfig和Hibernate配置。

我更新AppConfig以包含tile和jsp页面，两个viewresolvers分别有一个和两个排序。

为了简短起见，提供代码片段

User.Class

         @Entity
    @Table(name="USER_TABLE")

    public class User{

        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        @Column(name="userid", nullable=false)
        private int userid;
   ... 
...
    }

UserDetail.Class

 @Entity @Table(name="USER_DETAIL_TABLE")
public class UserDetail {

    //@Id
    @Column(name="userid", nullable=false)
    @Id @GeneratedValue(generator = "genuserid")
    @GenericGenerator(name = "genuserid", strategy="foreign", parameters =  @Parameter(value="USER_TABLE", name = "property") )
    private int userid;


    private String firstname;
    private String lastname;


    //@PrimaryKeyJoinColumn
    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name="userid")
    private User user;


    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }

UserDetailDao Class

@Repository("UserDetailDao")
public class UserDetailDaoImpl extends AbstractDao implements UserDetailDao {


    @Override
    public void saveUserDetail( UserDetail userdetail, User user) {
            // some time  userdetail.userid is 0!!
            //  and user.userid is 1 !!

        // setting User table info
        userdetail.setUser(user);

        //persist(userdetail);

        //getSession().beginTransaction(
        getSession().save(userdetail);
        //getSession().getTransaction().commit();

    }

UserDetailService类

@Service("userdetailService")
@Transactional
public class UserDetailServiceImpl implements  UserDetailService{

    @Autowired
    private UserDetailDao userDetailDao;

    @Override
    public void saveUserDetail(UserDetail userdetail,User user) {

        userDetailDao.saveUserDetail(userdetail, user);
    }

控制器类

@Controller
public class WebMainController {


    @Autowired
    UserDetailService userDetailService;

 //For add and update person both
        @RequestMapping(value= "useradd", method = RequestMethod.POST)
        public String addPerson(
  @ModelAttribute("userdetail") UserDetail userdetail,BindingResult resultUser,
  @ModelAttribute("user") User user,BindingResult resultUserdetail
                                )
       {

                //UserDetail userdetail = new UserDetail();
                //userdetail.setUser(user);
                userDetailService.saveUserDetail(userdetail, user);

            return "redirect:/useradd";
        }

使用MySQL：SQL脚本

CREATE  TABLE user_table (
  userid INT(10) not null auto_increment, 
  loginname VARCHAR(16) NOT NULL ,
  password VARCHAR(32) NOT NULL ,

  PRIMARY KEY (userid)
  )ENGINE=InnoDB  DEFAULT CHARSET=utf8;

 CREATE  TABLE user_detail_table(
  userid INT(10) not null, 
  firstname VARCHAR(16)  ,
   PRIMARY KEY (userid),
   FOREIGN KEY (userid) REFERENCES user_table (userid) 
   ON UPDATE CASCADE 
   ON DELETE CASCADE

  )ENGINE=InnoDB DEFAULT CHARSET=utf8;


INSERT INTO user_table(userid, loginname,password) VALUES (1,'admin','admin');
INSERT INTO user_detail_table(userid, firstname) VALUES (1,'Administrator');

又一个问题

我可以在＆＃39;用户＆＃39;中手动插入一行。和＆＃39; user_detail＆＃39;表格有“管理员”＃39;领域？注释@GeneratedValue检查数据库，然后递增（生成）用户标识的值，对不对？

异常错误如下

message Request processing failed; nested exception is java.lang.NullPointerException

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:978)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause

java.lang.NullPointerException
    org.hibernate.tuple.entity.AbstractEntityTuplizer.getPropertyValue(AbstractEntityTuplizer.java:650)
    org.hibernate.persister.entity.AbstractEntityPersister.getPropertyValue(AbstractEntityPersister.java:4736)
    org.hibernate.id.ForeignGenerator.generate(ForeignGenerator.java:96)
    org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:117)
    org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:209)
    org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
    org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:194)
    org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
    org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
    org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:715)
    org.hibernate.internal.SessionImpl.save(SessionImpl.java:707)
    org.hibernate.internal.SessionImpl.save(SessionImpl.java:702)
    com.cms.sweb.dao.UserDetailDaoImpl.saveUserDetail(UserDetailDaoImpl.java:49)
    com.cms.sweb.service.UserDetailServiceImpl.saveUserDetail(UserDetailServiceImpl.java:23)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
    org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    com.sun.proxy.$Proxy40.saveUserDetail(Unknown Source)
    com.cms.sweb.controller.WebMainController.addPerson(WebMainController.java:87)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/8.0.20 logs.

如果我错过任何内容，请告诉我，我会添加它。提前谢谢！

Answer 1

错误发生在GenericGenerator Annotation中。

 @GenericGenerator(name = "genuserid", strategy="foreign", parameters =  @Parameter(value="USER_TABLE", name = "property") )

正确的一个如下

 @GenericGenerator(name = "genuserid", strategy="foreign", parameters =  @Parameter(value="user", name = "property") )

'value'应该是外键映射到的对象。

Spring MVC + Hibernate +一对一映射：session.save

1 个答案: