java - Spring 4.3.0.RELEASE + Hibernate 5.2.0.Final -Error..根本原因是org.hibernate.PersistentObjectException

Question

更新: 错误已通过评论中的解决方案修复

尝试向“电子商务”表添加新行时出现此错误: 当我调用“this.ecommerceService.add(ecommerceEntity);”时会发生这种情况在主 Controller 中。

错误日志:

SEVERE: Servlet.service() for servlet [searcher] in context with path [/Searcher] threw exception [Request processing failed; nested exception is javax.persistence.PersistenceException: org.hibernate.PersistentObjectException: detached entity passed to persist: com.searcher.entity.EcommerceEntity] with root cause
org.hibernate.PersistentObjectException: detached entity passed to persist: com.searcher.entity.EcommerceEntity
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:124)
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:58)
    at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:756)
    at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:736)
    at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:741)
    at com.searcher.dao.EcommerceImp.add(EcommerceImp.java:29)
    at com.searcher.service.EcommerceServiceImp.add(EcommerceServiceImp.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:498)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333)
    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$1.proceedWithInvocation(TransactionInterceptor.java:99)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
    at com.sun.proxy.$Proxy33.add(Unknown Source)
    at com.searcher.controller.MainSearcherController.helloWorld(MainSearcherController.java:46)
    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:498)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
    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:622)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$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)

电子商务实体:

package com.searcher.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="ecommerce")
public class EcommerceEntity {

    @Id
    @Column(name="Id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int Id;

    @Column
    private String Name;

    @Column
    private String Path;

    public int getId() {
        return Id;
    }

    public void setId(int id) {
        this.Id = id;
    }

    public String getName() {
        return Name;
    }

    public void setName(String name) {
        this.Name = name;
    }

    public String getPath() {
        return Path;
    }

    public void setPath(String path) {
        this.Path = path;
    }

    @Override
    public String toString(){
        return "Id = " + Id + ", Name = " + Name + ", Path = " + Path;
    }

}

EcommerceDAO:

package com.searcher.dao;

import java.util.List;

import org.springframework.stereotype.Repository;

import com.searcher.entity.EcommerceEntity;

@Repository
public interface EcommerceDAO {

    public void add(EcommerceEntity eCommerce);
    public void edit(EcommerceEntity eCommerce);
    public void deleteById(int id);
    public EcommerceEntity getEcommerceById(int id);
    public List<EcommerceEntity> getAllEcommerce();
}

电子商务Imp:

package com.searcher.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.searcher.entity.EcommerceEntity;

@Repository
public class EcommerceImp implements EcommerceDAO{

    private static final Logger logger = LoggerFactory.getLogger(UserDAO.class);

    @Autowired
    private SessionFactory sessionFactory;

    public void setSessionFactory(SessionFactory sf){
        this.sessionFactory = sf;
    }

    @Override
    public void add(EcommerceEntity eCommerce) {
        Session ss = this.sessionFactory.getCurrentSession();
        ss.persist(eCommerce);
        logger.info("EcommerceEntity deleted successfully, EcommerceEntity Details="+eCommerce);
    }

    @Override
    public void edit(EcommerceEntity eCommerce) {
        this.sessionFactory.getCurrentSession().update(eCommerce);
        logger.info("EcommerceEntity updated successfully, EcommerceEntity Details="+eCommerce);
    }

    @Override
    public void deleteById(int id) {
        EcommerceEntity ecommerceToDelete = getEcommerceById(id);
        this.sessionFactory.getCurrentSession().delete(ecommerceToDelete);
        logger.info("EcommerceEntity deleted successfully, EcommerceEntity Details="+ecommerceToDelete);
    }

    @Override
    public EcommerceEntity getEcommerceById(int id) {
        EcommerceEntity ecommerceToReturn = (EcommerceEntity)this.sessionFactory.getCurrentSession().get(EcommerceEntity.class, id);
        logger.info("EcommerceEntity founded successfully, EcommerceEntity Details="+ecommerceToReturn);
        return ecommerceToReturn;
    }

    @SuppressWarnings("unchecked")
    @Override
    public List<EcommerceEntity> getAllEcommerce() {
        @SuppressWarnings("deprecation")
        List<EcommerceEntity> ecommerceList = this.sessionFactory.getCurrentSession().createQuery("from ecommerce").list();
        logger.info("List<EcommerceEntity> upload successfully, List<EcommerceEntity> Details="+ecommerceList.toString());
        return ecommerceList;
    }

}

电子商务服务:

package com.searcher.service;

import java.util.List;

import com.searcher.entity.EcommerceEntity;

public interface EcommerceService {
    public void add(EcommerceEntity eCommerce);
    public void edit(EcommerceEntity eCommerce);
    public void deleteById(int id);
    public EcommerceEntity getEcommerceById(int id);
    public List<EcommerceEntity> getAllEcommerce();
}

EcommerceServiceImp:

package com.searcher.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.searcher.dao.EcommerceDAO;
import com.searcher.entity.EcommerceEntity;

@Service("ecommerceService")
public class EcommerceServiceImp implements EcommerceService{

    @Autowired
    private EcommerceDAO ecommerceDAO;

    public void setEcommerceDAO(EcommerceDAO ecommeceDAO){
        this.ecommerceDAO = ecommeceDAO;
    }

    @Override
    @Transactional
    public void add(EcommerceEntity eCommerce) {

        this.ecommerceDAO.add(eCommerce);
    }

    public EcommerceDAO getEcommerceDAO() {
        return ecommerceDAO;
    }

    @Override
    @Transactional
    public void edit(EcommerceEntity eCommerce) {
        this.ecommerceDAO.edit(eCommerce);
    }

    @Override
    @Transactional
    public void deleteById(int id) {
        this.ecommerceDAO.deleteById(id);
    }

    @Override
    @Transactional
    public EcommerceEntity getEcommerceById(int id) {
        return this.ecommerceDAO.getEcommerceById(id);
    }

    @Override
    @Transactional
    public List<EcommerceEntity> getAllEcommerce() {
        return (List<EcommerceEntity>)this.ecommerceDAO.getAllEcommerce();
    }
}

主 Controller :

package com.searcher.controller;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import com.searcher.entity.EcommerceEntity;
import com.searcher.service.EcommerceService;
import com.searcher.service.EcommerceServiceImp;

@Controller
public class MainSearcherController {

    @Autowired
    private EcommerceService ecommerceService;


    @RequestMapping("/welcome")
    public ModelAndView helloWorld() {

        String message = "<br><div style='text-align:center;'>"
                + "<h3>********** Hello World, Spring MVC Tutorial</h3>This message is coming from MainSearcherController.java **********</div><br><br>";
        String strEndList = "";

        try {
            //ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("searcher-servlet.xml");
            //EcommerceDAO ecommerceDAO = context.getBean(EcommerceDAO.class);

            //EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("hibernate5AnnotatedSessionFactory");
            //EntityManager entityManager = entityManagerFactory.createEntityManager();


            // Creating ImageService object
            EcommerceEntity ecommerceEntity = new EcommerceEntity();

            ecommerceEntity.setId(4564564);
            ecommerceEntity.setName("Ebay");
            ecommerceEntity.setPath("www.ebay.com");

            this.ecommerceService.add(ecommerceEntity);


            //strEndList = "<br/><br/>" + ecommerceService.getAllEcommerce().toString() + "<br/><br/>";

        } catch (Exception e) {
            throw e;
        }


        return new ModelAndView("welcome", "message", message + strEndList);
    }

}

searcher-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc" 
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:beans="http://www.springframework.org/schema/beans"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/beans     
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context.xsd">

    <!-- Searcher-Servlet Context: defines this servlet's request-processing 
        infrastructure -->

    <!-- Enables the Spring MVC @Controller programming model -->
    <mvc:annotation-driven />

    <!-- Handles HTTP GET requests for /resources/** by efficiently serving 
        up static resources in the ${webappRoot}/resources directory -->
    <mvc:resources mapping="/resources/**" location="/resources/" />

    <context:annotation-config />

    <!-- Resolves views selected for rendering by @Controllers to .jsp resources 
        in the /WEB-INF/views directory -->
    <beans:bean id="viewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass"
            value="org.springframework.web.servlet.view.JstlView" />
        <beans:property name="prefix" value="/WEB-INF/jsp/" />
        <beans:property name="suffix" value=".jsp" />
    </beans:bean>

    <!-- DataSource -->
    <beans:bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
        destroy-method="close">
        <beans:property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <beans:property name="url"
            value="jdbc:mysql://localhost:3306/SearcherDB" />
        <beans:property name="username" value="root" />
        <beans:property name="password" value="root" />
    </beans:bean>



    <!-- Hibernate 5 SessionFactory Bean definition -->
    <beans:bean id="hibernate5AnnotatedSessionFactory"
        class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
        <beans:property name="dataSource" ref="dataSource" />
        <beans:property name="annotatedClasses">
            <beans:list>
                <beans:value>com.searcher.entity.EcommerceEntity</beans:value>
                <beans:value>com.searcher.entity.ImageEntity</beans:value>
                <beans:value>com.searcher.entity.ProductEntity</beans:value>
                <beans:value>com.searcher.entity.ProductRequestEntity</beans:value>
                <beans:value>com.searcher.entity.RequestEntity</beans:value>
                <beans:value>com.searcher.entity.SellerEntity</beans:value>
                <beans:value>com.searcher.entity.UserEntity</beans:value>
            </beans:list>
        </beans:property>
        <beans:property name="hibernateProperties">
            <beans:props>
                <beans:prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</beans:prop>
                <beans:prop key="hibernate.show_sql">true</beans:prop>
                <beans:prop key="hibernate.format_sql">true</beans:prop>
            </beans:props>
        </beans:property>
    </beans:bean>

    <!-- eCommerce -->
    <beans:bean id="ecommerceDAO" class="com.searcher.dao.EcommerceImp">
        <beans:property name="sessionFactory"
            ref="hibernate5AnnotatedSessionFactory" />
    </beans:bean>
    <beans:bean id="ecommerceService" class="com.searcher.service.EcommerceServiceImp">
        <beans:property name="ecommerceDAO" ref="ecommerceDAO">
        </beans:property>
    </beans:bean>

    <!-- Image -->
    <beans:bean id="imageDAO" class="com.searcher.dao.ImageImp">
        <beans:property name="sessionFactory"
            ref="hibernate5AnnotatedSessionFactory" />
    </beans:bean>
    <beans:bean id="imageService" class="com.searcher.service.ImageServiceImp">
        <beans:property name="imageDAO" ref="imageDAO">
        </beans:property>
    </beans:bean>

    <!-- Product -->
    <beans:bean id="productDAO" class="com.searcher.dao.ProductImp">
        <beans:property name="sessionFactory"
            ref="hibernate5AnnotatedSessionFactory" />
    </beans:bean>
    <beans:bean id="productService" class="com.searcher.service.ProductServiceImp">
        <beans:property name="productDAO" ref="productDAO">
        </beans:property>
    </beans:bean>

    <!-- ProductRequest -->
    <beans:bean id="productRequestDAO" class="com.searcher.dao.ProductRequestImp">
        <beans:property name="sessionFactory"
            ref="hibernate5AnnotatedSessionFactory" />
    </beans:bean>
    <beans:bean id="productRequestService"
        class="com.searcher.service.ProductRequestServiceImp">
        <beans:property name="productRequestDAO" ref="productRequestDAO">
        </beans:property>
    </beans:bean>

    <!-- Request -->
    <beans:bean id="requestDAO" class="com.searcher.dao.RequestImp">
        <beans:property name="sessionFactory"
            ref="hibernate5AnnotatedSessionFactory" />
    </beans:bean>
    <beans:bean id="requestService" class="com.searcher.service.RequestServiceImp">
        <beans:property name="requestDAO" ref="requestDAO">
        </beans:property>
    </beans:bean>

    <!-- Seller -->
    <beans:bean id="sellerDAO" class="com.searcher.dao.SellerImp">
        <beans:property name="sessionFactory"
            ref="hibernate5AnnotatedSessionFactory" />
    </beans:bean>
    <beans:bean id="sellerService" class="com.searcher.service.SellerServiceImp">
        <beans:property name="sellerDAO" ref="sellerDAO">
        </beans:property>
    </beans:bean>

    <!-- User -->
    <beans:bean id="userDAO" class="com.searcher.dao.UserImp">
        <beans:property name="sessionFactory"
            ref="hibernate5AnnotatedSessionFactory" />
    </beans:bean>
    <beans:bean id="userService" class="com.searcher.service.UserServiceImp">
        <beans:property name="userDAO" ref="userDAO">
        </beans:property>
    </beans:bean>

    <context:component-scan base-package="com.searcher." />

    <tx:annotation-driven transaction-manager="transactionManager" />

    <beans:bean id="transactionManager"
        class="org.springframework.orm.hibernate5.HibernateTransactionManager">
        <beans:property name="sessionFactory"
            ref="hibernate5AnnotatedSessionFactory" />
    </beans:bean>

</beans>

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>Searcher</groupId>
    <artifactId>Searcher</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <dependencies>
        <!-- Spring -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.0.RELEASE</version>
            <exclusions>
            <!-- Exclude Commons Logging in favor of SLF4j -->
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                 </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.3.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>4.3.0.RELEASE</version>
        </dependency>


        <!-- Hibernate -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>5.1.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.2.0.Final</version>
        </dependency>


        <!-- Apache Commons DBCP -->
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.4</version>
        </dependency>

        <!-- Spring ORM -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>4.3.0.RELEASE</version>
        </dependency>

        <!-- AspectJ -->
        <dependency>
            <groupId>aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.5.4</version>
        </dependency>

        <!-- Logging -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.21</version>
        </dependency>
            <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
            <version>1.7.21</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.21</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
            <exclusions>
                <exclusion>
                    <groupId>javax.mail</groupId>
                    <artifactId>mail</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.jms</groupId>
                    <artifactId>jms</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.sun.jdmk</groupId>
                    <artifactId>jmxtools</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.sun.jmx</groupId>
                    <artifactId>jmxri</artifactId>
                </exclusion>
            </exclusions>
            <scope>runtime</scope>
        </dependency>

        <!-- @Inject -->
        <dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
        </dependency>

        <!-- Servlet -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <!-- Test -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

    <dependency>
        <groupId>javax.transaction</groupId>
        <artifactId>jta</artifactId>
        <version>1.1</version>
    </dependency>



    </dependencies>

    <!-- Build -->
    <build>
    <sourceDirectory>src</sourceDirectory>
    <plugins>
        <plugin>
            <artifactId>maven-eclipse-plugin</artifactId>
            <version>2.9</version>
            <configuration>
                <additionalProjectnatures>
                    <projectnature>org.springframework.ide.eclipse.core.springnature</projectnature>
                </additionalProjectnatures>
                <additionalBuildcommands>
                    <buildcommand>org.springframework.ide.eclipse.core.springbuilder</buildcommand>
                </additionalBuildcommands>
                <downloadSources>true</downloadSources>
                <downloadJavadocs>true</downloadJavadocs>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.5.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
                <compilerArgument>-Xlint:all</compilerArgument>
                <showWarnings>true</showWarnings>
                <showDeprecation>true</showDeprecation>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.2.1</version>
            <configuration>
                <mainClass>org.test.int1.Main</mainClass>
            </configuration>
        </plugin>

    </plugins>
    </build>
</project>

Answer 1

空指针异常

第一个异常NullPointerException是由于引用分配问题造成的。 Controller 无法识别服务类 EcommerceService。

java.lang.NullPointerException at com.searcher.controller.MainSearcherController.helloWorld(MainSearcherController.java:46) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

在MainSearcherController中添加标签@Autowired可以解决这个问题。

@Autowired
private EcommerceService ecommerceService;

持久对象异常

第二个异常PersistentObjectException是由于Hibernate中的标识符冲突造成的。 EcommerceEntity 使用注释@GeneratedValue。这个标签会让 hibernate 为你生成 Id，但同时，你在 Controller 中给出了另一个 Id:

ecommerceEntity.setId(4564564);

所以 Hibernate 不知道该怎么办。由于 @GenerateValue 在 Hibernate 中大量使用，解决方案是禁用 ID setter。有关更多详细信息，您可以查看:Stack Overflow • org.hibernate.PersistentObjectException: detached entity passed to persist - with JPA 。