hibernate rest Web服务nullpointerexception

daolsyd0  于 2021-07-09  发布在  Java
关注(0)|答案(1)|浏览(309)

我的项目不断抛出nullpointerexceptions，我不知道为什么。
这是控制器类：

package Hello;
@Controller
public class eventController {
   @Autowired
   private EventRepository eventRepo;

   @RequestMapping(value = "/create")
   @ResponseBody
   public ResponseEntity<String> create(String name, String location, Double longitude, Double latitude, String dateS,
        String homepage, String sport, String start, String end, String tracking, String fee, String host,
        String eMail, String track, String info) {
        event = new Event(name, location, longitudeS, latitudeS, date, homepage, sport, start, end, tracking, fee,
                host, eMail, track, info);
        eventRepo.save(event);
        [...]
}

@RequestMapping(value = "/get-by-name")
@ResponseBody
public Event getByName(String name) {
    Date date;
    Event event;
    Iterable<Event> source;
    ArrayList<Event> eventList;
    System.out.println(name);
    try {
        source = eventRepo.findAll();
        eventList = new ArrayList<>();
        source.forEach(eventList::add);
    } catch (Exception ex) {
        ex.printStackTrace();
        return null;
    }
    return eventList.get(0);
}

}

第一个方法执行它必须执行的操作，并且不会引发异常。问题在于 getByName 方法。总是存在nullpointerexception。对应实体：

package Hello;
@Entity
@IdClass(PK.class)
@Table(name = "event")
public class Event implements Serializable {
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    @Id
    public String name;
    public String location;
    @Id
    public String longitude;
    @Id
    public String latitude;
    @Id
    @Temporal(TemporalType.DATE)
    public Date date;
    public String homepage;
    public String sport;
    public String start;
    public String end;
    public String tracking;
    public String fee;
    public String host;
    public String eMail;
    public String track;
    public String info;

    public Event() {
    }

    public Event(String name, String location, String longitude, String latitude, Date date, String homepage,
            String sport, String start, String end, String tracking, String fee, String host, String eMail,
            String track, String info) {
        super();
        this.name = name;
        this.location = location;
        this.longitude = longitude;
        this.latitude = latitude;
        this.date = date;
        this.homepage = homepage;
        this.sport = sport;
        this.start = start;
        this.end = end;
        this.tracking = tracking;
        this.fee = fee;
        this.host = host;
        this.eMail = eMail;
        this.track = track;
        this.info = info;
    }

    public Event(int id, String name, String location, String longitude, String latitude, Date date, String homepage,
            String sport, String start, String end, String tracking, String fee, String host, String eMail,
            String track, String info) {
        super();
        this.id = id;
        this.name = name;
        this.location = location;
        this.longitude = longitude;
        this.latitude = latitude;
        this.date = date;
        this.homepage = homepage;
        this.sport = sport;
        this.start = start;
        this.end = end;
        this.tracking = tracking;
        this.fee = fee;
        this.host = host;
        this.eMail = eMail;
        this.track = track;
        this.info = info;
    }

    //Setter and Getter for every field
}

这是相应的接口：

package Hello;

import javax.transaction.Transactional;

import org.springframework.data.repository.CrudRepository;

@Transactional
public interface EventRepository extends CrudRepository<Event, Long> {

    public Event findByName(String name);

}

这是控制台输出。我寻找这个问题，但没有找到解决办法。

java.lang.NullPointerException
    at org.hibernate.internal.util.StringHelper.root(StringHelper.java:374)
    at org.hibernate.persister.entity.AbstractEntityPersister.getSubclassPropertyTableNumber(AbstractEntityPersister.java:1832)
    at org.hibernate.persister.entity.BasicEntityPropertyMapping.toColumns(BasicEntityPropertyMapping.java:46)
    at org.hibernate.persister.entity.AbstractEntityPersister.toColumns(AbstractEntityPersister.java:1775)
    at org.hibernate.hql.internal.ast.tree.FromElement.getIdentityColumns(FromElement.java:352)
    at org.hibernate.hql.internal.ast.tree.IdentNode.resolveAsAlias(IdentNode.java:149)
    at org.hibernate.hql.internal.ast.tree.IdentNode.resolve(IdentNode.java:86)
    at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:109)
    at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:104)
    at org.hibernate.hql.internal.ast.HqlSqlWalker.resolve(HqlSqlWalker.java:942)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.propertyRef(HqlSqlBaseWalker.java:1162)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectExpr(HqlSqlBaseWalker.java:2284)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectExprList(HqlSqlBaseWalker.java:2225)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectClause(HqlSqlBaseWalker.java:1496)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:581)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:309)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:257)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:262)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:190)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:142)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:115)
    at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:76)
    at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:150)
    at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:302)
    at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:240)
    at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1894)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:531)
    at org.hibernate.jpa.criteria.CriteriaQueryImpl$1.buildCompiledQuery(CriteriaQueryImpl.java:316)
    at org.hibernate.jpa.criteria.compile.CriteriaCompiler.compile(CriteriaCompiler.java:130)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:699)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:347)
    at com.sun.proxy.$Proxy83.createQuery(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:298)
    at com.sun.proxy.$Proxy83.createQuery(Unknown Source)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.getQuery(SimpleJpaRepository.java:656)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.getQuery(SimpleJpaRepository.java:633)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.findAll(SimpleJpaRepository.java:329)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.findAll(SimpleJpaRepository.java:74)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:504)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:489)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:461)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:133)
    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.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:57)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
    at com.sun.proxy.$Proxy85.findAll(Unknown Source)
    at Hello.eventController.getByName(eventController.java:119)
    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.doInvoke(InvocableHandlerMethod.java:205)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)

谢谢你的帮助。如果你需要更多的信息，请告诉我。

JavaHibernaterestNullPointerExceptionweb-services

1条答案

按热度按时间
wwtsj6pe

wwtsj6pe1#

使用复合id和名为id的属性时出现问题：https://hibernate.atlassian.net/browse/hhh-1851.
将字段名id更改为其他名称，这样可以解决您的问题

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