我曾经在一个小项目中使用maven，Hibernate，spring和JPA存储库。我高兴地假设这里的信息
http://docs.spring.io/spring-data/jpa/docs/1.4.2.RELEASE/reference/html/jpa.repositories.html
足以创建至少一个简单的应用程序。不幸的是，事实并非如此。我已经设法从MySQL数据库中读取数据，但是现在无法插入任何数据。
这是一个简单的'用户'模型类。
@Entity
@Table(name = "ctuser")
public class User implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long uid;
@Column(name = "Gmail", nullable = false)
private String gmail;
public String getGmail() {
return gmail;
}
public void setGmail(String gmail) {
this.gmail = gmail;
}
@Override
public String toString() {
return getGmail();
}
}
我已经创建了一个合适的存储库界面......
package put.io.come_together.service.persistance.repository;
import org.springframework.data.jpa.repository.JpaRepository;
import put.io.come_together.model.User;
public interface UserRepository extends JpaRepository<User, Long> {
User findUserByUid(long uid);
User save (User obj);
}
......服务的界面......
public interface UserService {
User getUser(long uid);
User addUser(User obj);
List<User> getAll();
}
......以及界面的实现。
@Service
public class UserServiceImpl implements UserService {
private final UserRepository userRepository;
@Autowired
public UserServiceImpl(UserRepository userRepository) {
this.userRepository = userRepository;
}
@Override
public User getUser(long uid) {return userRepository.findUserByUid(uid);
}
@Transactional
@Override
public User addUser(User obj) {return this.userRepository.saveAndFlush(obj);}
@Override
public List<User> getAll() {
return userRepository.findAll();
}
最后，我试图将数据作为数据呈现，并在数据库中插入内容。
@Controller
public class HomePageController {
@Autowired
private UserService userService;
private static final String USER_MAP_KEY = "groups";
private static final String USER_LIST_TEMPLATE_NAME = "groupList";
@RequestMapping("/")
String hello(Map<String, Object> model) {
User osoba = new User();
osoba.setGmail("ADAMWEST");
userService.addUser(osoba);
List<User> userGroupsList = userService.getAll();
model.put(USER_MAP_KEY, userGroupsList);
return USER_LIST_TEMPLATE_NAME;
}
}
如果我遗漏“userService.addUser（osoba）;”线，一切正常。我可以看到从数据库中读取的数据整齐划出。但是当我尝试实际使用.addUser（）方法时，我的localhost会输出一个whitelabel错误页面。
Whitelabel错误页面
此应用程序没有/ error的显式映射，因此您将此视为回退。 Sun Apr 19 09:36:52 CEST 2015 出现意外错误（type = Internal Server Error，status = 500）。 无法执行声明;嵌套异常是org.hibernate.exception.GenericJDBCException：无法执行语句
请您告诉我，我做错了什么？我一直试图解决这个问题一段时间，并彻底失去了希望。
这是异常的堆栈跟踪。该错误涉及字段'UID'没有默认值，但我将其标记为@Id字段。我还会删除整个数据库并重新设置它，因为它帮助了有类似问题的人。
java.sql.SQLException: Field 'UID' doesn't have a default value
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:996)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3887)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3823)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2435)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2582)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2530)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1907)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2141)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2077)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2062)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:208)
at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:96)
at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:58)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3032)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3558)
at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:98)
at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:492)
at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:197)
at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:181)
at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:216)
at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:324)
at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:
288)
at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:194)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:125
)
at org.hibernate.jpa.event.internal.core.JpaPersistEventListener.saveWithGeneratedId(JpaPersistEventListener.jav
a:84)
at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:2
06)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:149)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:75)
at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:811)
at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:784)
at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:789)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:1181)
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.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(Extend
edEntityManagerCreator.java:344)
at com.sun.proxy.$Proxy78.persist(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEnti
tyManagerCreator.java:291)
at com.sun.proxy.$Proxy78.persist(Unknown Source)
at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:407)
at org.springframework.data.jpa.repository.support.SimpleJpaRepository.saveAndFlush(SimpleJpaRepository.java:421
)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.exec
uteMethodOn(RepositoryFactorySupport.java:416)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doIn
voke(RepositoryFactorySupport.java:401)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invo
ke(RepositoryFactorySupport.java:373)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$DefaultMethodInvokingMethodIntercep
tor.invoke(RepositoryFactorySupport.java:486)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterce
ptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspec
tSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTransla
tionInterceptor.java:136)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingM
ethodIntercceptor.invoke(CrudMethodMetadataPostProcessor.java:122)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
at com.sun.proxy.$Proxy80.saveAndFlush(Unknown Source)
at put.io.come_together.service.persistance.impl.UserServiceImpl.addUser(UserServiceImpl.java:26)
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.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:
190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterce
ptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspec
tSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
at com.sun.proxy.$Proxy83.addUser(Unknown Source)
at put.io.come_together.controller.HomePageController.hello(HomePageController.java:29)
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.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:13
7)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletIn
vocableHandlerMethod.java:110)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(Request
MappingHandlerAdapter.java:777)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMapp
ingHandlerAdapter.java:706)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.j
ava:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:943)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
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.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
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.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1086)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:659)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1558)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1515)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
答案 0 :(得分：2)
你说Hibernate使用策略AUTO自动生成ID。使用MySQL的这种策略包括让数据库使用自动增量列生成ID。因此，如果您没有将uid定义为自动增量，则无法正常工作。