如何使用Hutsnate提供的struts2框架上的JPA扩展来访问数据库？-Java 学习之路

我一直在学习基于struts 2的开发，并且很难在struts 2上使用Hibernate提供的JPA扩展来访问数据库的基本CRUD功能 .

我使用maven作为构建工具，我已经被困在这里一个星期或其他什么 .

我认为我无法适应persistence.xml文件或某些所需的映射文件，但是有人可以给我一些步骤，以便使用上述技术访问数据库 .

我正在使用MySQL数据库，下面给出的是代码：

persistence.xml

<persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLNSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml" version="2.0">

    <persistence-unit name="APP">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <class>com.app.classes.User</class>
        <mapping-file>User.hbm.xml</mapping-file>
        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
            <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource" />
            <property name="hibernate.connection.url" value="jdbc:mysql://localhost/APP" />
            <property name="hibernate.connection.username" value="root" />
            <property name="hibernate.connection.password" value="9250864418" />
            <property name="hibernate.hbm2ddl.auto" value="update" />
            <property name="hibernate.archive.autodetection" value="class" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true" />
        </properties>
</persistence>

User.java (Object Model class)

package com.app.classes;

import javax.persistence.Entity;
import javax.persistence.Column;
import javax.persistence.Id;
import javax.persistence.Table;
import java.io.*;

@Entity
@Table(name = "APP_USER", schema = "APP")
public class User implements Serializable {
    private String firstName;
    private String lastName;
    private String emailId;
    private String password;

    @Id
    @Column(name = "EMAIL")
    public String getEmailId() {
        return emailId;
    }

    public void setEmailId(String emailId) {
        this.emailId = emailId;
    }

    @Column(name = "FIRST_NAME")
    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    @Column(name = "LAST_NAME")
    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    @Column(name = "USER_PASSWORD")
    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

BaseAction.java (Action class)

package com.app.action;

import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
import com.opensymphony.xwork2.Preparable;
import com.service.UserService;

public class BaseAction extends ActionSupport implements ModelDriven<User>, Preparable {
    private User user;
    private String emailId;
    protected UserService service;

    @Override
    public User getModel() {
        return user;
    }

    public void getEmailId(String emailId) {
        this.emailId = emailId;
    }

    public String setEmailid() {
        return emailId;
    }

    public void setUserService(UserService service) {
        this.service = service;
    }

    @Override
    public void prepare() throws Exception {
        if (emailId == null || "".equals(emailId)) {
            user = new User();
        } else {
            user = service.findByEmailId(user.getEmailId());
        }
    }

    @Override
    public String execute() throws Exception {
        return SUCCESS;
    }
}

UserServiceImpl class(class implementing service)

package com.app.service;

import org.hibernate.Session;

import java.util.*;
import com.app.classes.User;
import com.app.classes.HibernateUtil;
import javax.persistence.*;

public class UserServiceImpl implements UserService {
    private EntityManager em;

    public void setEntityManager(EntityManager em) {
        this.em = em;
    }

    public void save(User user) {
        if (user.getEmailId() == null) {
            // new
            em.persist(user);
        } else {
            // update
            em.merge(user);
        }
    }

    private EntityManager getEntityManager() {
        return em;
    }

    public User findByEmailId(String emailId) {
        return em.find(User.class, emailId);
    }
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app id="starter" version="2.4" 
         xmlns="http://java.sun.com/xml/ns/j2ee" 
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
         xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

    <display-name>Struts 2 - Maven Archetype - Starter</display-name>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath*:applicationContext*.xml</param-value>
    </context-param>

    <!-- Filters -->
    <filter>
        <filter-name>action2-cleanup</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ActionContextCleanUp</filter-class>
    </filter>
    <filter>
        <filter-name>sitemesh</filter-name>
        <filter-class>com.opensymphony.module.sitemesh.filter.PageFilter</filter-class>
    </filter>
    <filter>
        <filter-name>action2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>action2-cleanup</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <filter-mapping>
        <filter-name>sitemesh</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <filter-mapping>
        <filter-name>action2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!-- Listeners -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>


    <!-- Servlets -->
    <servlet>
        <servlet-name>dwr</servlet-name>
        <servlet-class>uk.ltd.getahead.dwr.DWRServlet</servlet-class>
        <init-param>
            <param-name>debug</param-name>
            <param-value>true</param-value>
        </init-param>
    </servlet>
    <servlet>
        <servlet-name>jspSupportServlet</servlet-name>
        <servlet-class>org.apache.struts2.views.JspSupportServlet</servlet-class>
        <load-on-startup>5</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>dwr</servlet-name>
        <url-pattern>/dwr/*</url-pattern>
    </servlet-mapping>


    <!-- Welcome file lists -->
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.jsp</welcome-file>
        <welcome-file>index.html</welcome-file>
    </welcome-file-list>
</web-app>

Struts.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE struts PUBLIC 
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
    <package name="myPackage" extends="struts-default">
    <default-interceptor-ref name="paramsPrepareParamsStack" />
        <action name="base" class="com.app.action.BaseAction">
            <result>/jsp/user.jsp</result>
        </action>
    </package>
</struts>

我就像Sourav所说的那样，但是在bean创建中仍然存在一些问题，这里spring无法创建应用程序context.xml文件中定义的bean . 这个bean基本上是我的UserServiceImpl类，所以我提供了服务器堆栈跟踪，任何建议都会有所帮助

SEVERE: Context initialization failed

org.springframework.beans.factory.BeanCreationException：在文件[/home/ankur/Desktop/app/target/classes/applicationContext.xml]中定义名称为'userService'的bean时出错：bean的实例化失败;嵌套异常是org.springframework.beans.BeanInstantiationException：无法实例化bean类[com.app.service.UserServiceImpl]：构造函数抛出异常;嵌套异常是java.lang.NoClassDefFoundError：org / jboss / util / file / ArchiveBrowser $在org.springframework.beans.factory的org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean（AbstractAutowireCapableBeanFactory.java:883）中过滤 . support.AbstractAutowireCapableBeanFactory.createBeanInstance（AbstractAutowireCapableBeanFactory.java:839）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:440）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory $ 1.run（AbstractAutowireCapableBeanFactory .java：409）位于org.springframework.beans.factory.support.AbstractBeanFactory的org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean（AbstractAutowireCapableBeanFactory.java:380）的java.security.AccessController.doPrivileged（Native Method） org.springframework.beans.factory.support.De上的$ 1.getObject（AbstractBeanFactory.java:264）在org.springframework.beans.factory.support.AbstractBeanFactory.getBean的Org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（AbstractBeanFactory.java:261）中的faultSingletonBeanRegistry.getSingleton（DefaultSingletonBeanRegistry.java:222）（AbstractBeanFactory.java： 185）在org.springframework.context的org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:164）org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons（DefaultListableBeanFactory.java:429） .support.AbstractApplicationContext.finishBeanFactoryInitialization（AbstractApplicationContext.java:728）org.springframework.context.support.AbstractApplicationContext.refresh（AbstractApplicationContext.java:380）org.springframework.web.context.ContextLoader.createWebApplicationContext（ContextLoader.java:255））org.springframework.web.con上的org.springframework.web.context.ContextLoader.initWebApplicationContext（ContextLoader.java:199） text.ContextLoaderListener.contextInitialized（ContextLoaderListener.java:45）atg.mortbay.jetty.handle.ContextHandler.startContext（ContextHandler.java:548）org.mortbay.jetty.servlet.Context.startContext（Context.java:136） org.mortbay.jetty.webapp.WebAppContext.startContext（WebAppContext.java:1250）位于org.mortbay.jetty.webapp.WebAppContext.doStart的org.mortbay.jetty.handler.ContextHandler.doStart（ContextHandler.java:517）（webAppContext.java:467）org.mortbay.jet.plugin.Jetty6PluginWebAppContext.doStart（Jetty6PluginWebAppContext.java:115）位于org.mortbay.jet的org.mortbay.component.AbstractLifeCycle.start（AbstractLifeCycle.java:50） . handler.HandlerCollection.doStart（HandlerCollection.java:152）org.mortbay.jetty.handler.ContextHandlerCollection.doStart（ContextHandlerCollection.java:156）org.mortbay.component.AbstractLifeCycle.start（AbstractLifeCycle.java:50）at org org.mortbay.component.Abst中的.mortbay.jetty.handler.HandlerCollection.doStart（HandlerCollection.java:152） ractLifeCycle.start（AbstractLifeCycle.java:50）atorg.mortbay.jetty.handler.HandlerWrapper.doStart（HandlerWrapper.java:130）在org.mortbay.jetty.Server.doStart（Server.java:224）在org.mortbay.component.AbstractLifeCycle.start（AbstractLifeCycle.java： 50）在org.mortbay.jetty.plugin.Jetty6PluginServer.start（Jetty6PluginServer.java:132）在org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty（AbstractJettyMojo.java:441）在org.mortbay.jetty.plugin.AbstractJettyMojo org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute（AbstractJettyRunMojo.java:210）中的org.mortbay.jetty.plugin.Jetty6RunMojo.execute（Jetty6RunMojo.java:184）上的.execute（AbstractJettyMojo.java:383） . org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals（DefaultLifecycleExecutor.java:694）中的apache.maven.plugin.DefaultPluginManager.executeMojo（DefaultPluginManager.java:490）位于org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandaloneGoal（DefaultLifecycleExecutor . java：569）at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal（DefaultLifecy） cleOecutor.java:539）org.apache.maache.maven.life.DefaultLifecycleExecutor.executeGoalAndHandleFailures（DefaultLifecycleExecutor.java:387）org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments（DefaultLifecycleExecutor.java:348）org.apache.maven .lifecycle.DefaultLifecycleExecutor.execute（DefaultLifecycleExecutor.java:180）在org.apache.maven.DefaultMaven.doExecute（DefaultMaven.java:328）在org.apache.maven.DefaultMaven.execute（DefaultMaven.java:138）在有机apache.maven.cli.MavenCli.main（MavenCli.java:362）atg.apache.maven.cli.compat.CompatibleMain.main（CompatibleMain.java:60）at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method）at at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:57）位于org.codehaus的java.lang.reflect.Method.invoke（Method.java:616）的sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43） .classworlds.Launcher.launchEnhanced（Launcher.java:315）org.codehaus.classworlds.Launc her.launch（Launcher.java:255）org.codehaus.classworlds.Launcher.mainWithExitCode（Launcher.java:430）at org.codehaus.classworlds.Launcher.main（Launcher.java:375）引起：org.springframework .beans.BeanInstantiationException：无法实例化bean类[com.app.service.UserServiceImpl]：构造函数抛出异常;嵌套的例外是java.lang.NoClassDefFoundError：在org.springframework.beans.BeanUtils.instantiateClass（BeanUtils.java:115）在org.springframework.beans.factory.support.SimpleInstantiationStrategy组织/ JBoss的/ UTIL /文件/ ArchiveBrowser $筛选 . 在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean（AbstractAutowireCapableBeanFactory.java:877）实例化（SimpleInstantiationStrategy.java:61）... 55更多引起：java.lang.NoClassDefFoundError：org / jboss / util / file / ArchiveBrowser $在javax.persistence.Persistence.createEntityManagerFactory（Persistence.java:83）的javax.persistence.Persistence.createEntityManagerFactory（Persistence.java:60）中的org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory（HibernatePersistence.java:119）处过滤）在sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructor）的sun.reflect.NativeConstructorAccessorImpl.newInstance0（Native Method）的com.app.service.UserServiceImpl . （UserServiceImpl.java:10）处 . AccessorImpl.java:57）位于org.springframework.beans.BeanUtils.instantiateClass（BeanUtils）的java.lang.reflect.Constructor.newInstance（Constructor.java:532）中的sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45） .java：100）... 57更多引起：java.lang.ClassNotFoundException：org.jboss.util.file.ArchiveBrowser $在java.security上的java.net.URLClassLoader $ 1.run（URLClassLoader.java:217）过滤位于org.codehaus.classworlds.RealmClassLoader.loadClassDirect（RealmClassLoader）的java.lang.ClassLoader.loadClass（ClassLoader.java:321）java.net.URLClassLoader.findClass（URLClassLoader.java:205）上的.AccessController.doPrivileged（Native Method）的.java：195）在org.codehaus.classworlds.DefaultClassRealm.loadClass（DefaultClassRealm.java:255）在org.codehaus.classworlds.DefaultClassRealm.loadClass（DefaultClassRealm.java:274）在org.codehaus.classworlds.RealmClassLoader.loadClass（ RealmClassLoader.java:214）at java.lang.ClassLoader.loadClass（ClassLoader.java:266 ）org.mortbay.jetty.webapp.WebAppClassLoader.loadClass（WebAppClassLoader.java:401）org.mortbay.jetty.webapp.WebAppClassLoader.loadClass（WebAppClassLoader.java:363）...更66 2011-07-11 17：49：00.008 :: WARN：上下文org.mortbay.jetty.plugin.Jetty6PluginWebAppContext@7e5619的启动失败{/应用程序，/家庭/ ANKUR /桌面/应用/ SRC /主/ web应用} org.springframework.beans.factory.BeanCreationException：在文件[/home/ankur/Desktop/app/target/classes/applicationContext.xml]中定义名称为'userService'的bean时出错：bean的实例化失败;嵌套异常是org.springframework.beans.BeanInstantiationException：无法实例化bean类[com.app.service.UserServiceImpl]：构造函数抛出异常;嵌套异常是java.lang.NoClassDefFoundError：org / jboss / util / file / ArchiveBrowser $在org.springframework.beans.factory的org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean（AbstractAutowireCapableBeanFactory.java:883）中过滤 . support.AbstractAutowireCapableBeanFactory.createBeanInstance（AbstractAutowireCapableBeanFactory.java:839）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:440）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory $ 1.run（AbstractAutowireCapableBeanFactory .java：409）位于org.springframework.beans.factory.support.AbstractBeanFactory的org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean（AbstractAutowireCapableBeanFactory.java:380）的java.security.AccessController.doPrivileged（Native Method） org.springframework.beans.factory.support.De上的$ 1.getObject（AbstractBeanFactory.java:264）在org.springframework.beans.factory.support.AbstractBeanFactory.getBean的Org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（AbstractBeanFactory.java:261）中的faultSingletonBeanRegistry.getSingleton（DefaultSingletonBeanRegistry.java:222）（AbstractBeanFactory.java： 185）在org.springframework.context的org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:164）org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons（DefaultListableBeanFactory.java:429） .support.AbstractApplicationContext.finishBeanFactoryInitialization（AbstractApplicationContext.java:728）org.springframework.context.support.AbstractApplicationContext.refresh（AbstractApplicationContext.java:380）org.springframework.web.context.ContextLoader.createWebApplicationContext（ContextLoader.java:255））org.springframework.web.con上的org.springframework.web.context.ContextLoader.initWebApplicationContext（ContextLoader.java:199） text.ContextLoaderListener.contextInitialized（ContextLoaderListener.java:45）atg.mortbay.jetty.handle.ContextHandler.startContext（ContextHandler.java:548）org.mortbay.jetty.servlet.Context.startContext（Context.java:136） org.mortbay.jetty.webapp.WebAppContext.startContext（WebAppContext.java:1250）位于org.mortbay.jetty.webapp.WebAppContext.doStart的org.mortbay.jetty.handler.ContextHandler.doStart（ContextHandler.java:517）（webAppContext.java:467）org.mortbay.jet.plugin.Jetty6PluginWebAppContext.doStart（Jetty6PluginWebAppContext.java:115）位于org.mortbay.jet的org.mortbay.component.AbstractLifeCycle.start（AbstractLifeCycle.java:50） . handler.HandlerCollection.doStart（HandlerCollection.java:152）org.mortbay.jetty.handler.ContextHandlerCollection.doStart（ContextHandlerCollection.java:156）org.mortbay.component.AbstractLifeCycle.start（AbstractLifeCycle.java:50）at org org.mortbay.component.Abst中的.mortbay.jetty.handler.HandlerCollection.doStart（HandlerCollection.java:152） ractLifeCycle.start（AbstractLifeCycle.java:50）在org.mortbay.jetty.handler.HandlerWrapper.doStart（HandlerWrapper.java:130）在org.mortbay.jetty.Server.doStart（Server.java:224）在org.mortbay .component.AbstractLifeCycle.start（AbstractLifeCycle.java:50）在org.mortbay.jetty.plugin.Jetty6PluginServer.start（Jetty6PluginServer.java:132）在org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty（AbstractJettyMojo.java:441 ）在org.mortbay.jetty.plugin.AbstractJettyMojo.execute（AbstractJettyMojo.java:383）在org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute（AbstractJettyRunMojo.java:210）在org.mortbay.jetty.plugin.Jetty6RunMojo . 执行（Jetty6RunMojo.java:184）在org.apache.maven.plugin.DefaultPluginManager.executeMojo（DefaultPluginManager.java:490）在org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals（DefaultLifecycleExecutor.java:694）在org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandaloneGoal（DefaultLifecycleExecutor.java:569）org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal（DefaultLifecycleExecutor.java:539）org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures（ DefaultLifecycleExecutor.java:387）位于org.apache.maven.maven的org.apache.maven.maven.life.life.DefaultLifecycleExecutor.execute（DefaultLifecycleExecutor.java:180）的org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments（DefaultLifecycleExecutor.java:348） .defaultMaven.doExecute（DefaultMaven.java:328）org.apache.maven.DefaultMaven.execute（DefaultMaven.java:138）org.apache.maven.cli.MavenCli.main（MavenCli.java:362）org . 位于sun.reflect的sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:57）的sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method）中的apache.maven.cli.compat.CompatibleMain.main（CompatibleMain.java:60） . DelegatingMethodAccessorImpl.invoke（德勒atingMethodAccessorImpl.java:43）atg.codehaus.classworlds.Launcher.launchEnhanced（Launcher.java:315）atg.codehaus.classworlds.Launcher.launch的java.lang.reflect.Method.invoke（Method.java:616）（Launcher.java:255）org.codehaus.classworlds.Launcher.mainWithExitCode（Launcher.java:430）org.codehaus.classworlds.Launcher.main（Launcher.java:375）引起：org.springframework.beans . BeanInstantiationException：无法实例化bean类[com.app.service.UserServiceImpl]：构造函数抛出异常;嵌套的例外是java.lang.NoClassDefFoundError：在org.springframework.beans.BeanUtils.instantiateClass（BeanUtils.java:115）在org.springframework.beans.factory.support.SimpleInstantiationStrategy组织/ JBoss的/ UTIL /文件/ ArchiveBrowser $筛选 . 在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean（AbstractAutowireCapableBeanFactory.java:877）实例化（SimpleInstantiationStrategy.java:61）... 55更多引起：java.lang.NoClassDefFoundError：org / jboss / util / file / ArchiveBrowser $在javax.persistence.Persistence.createEntityManagerFactory（Persistence.java:83）的javax.persistence.Persistence.createEntityManagerFactory（Persistence.java:60）中的org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory（HibernatePersistence.java:119）处过滤）在sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructor）的sun.reflect.NativeConstructorAccessorImpl.newInstance0（Native Method）的com.app.service.UserServiceImpl . （UserServiceImpl.java:10）处 . AccessorImpl.java:57）位于org.springframework.beans.BeanUtils.instantiateClass（BeanUtils）的java.lang.reflect.Constructor.newInstance（Constructor.java:532）中的sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45） .java：100）... 57更多引起：java.lang.ClassNotFoundException：org.jboss.util.file.ArchiveBrowser $在java.security上的java.net.URLClassLoader $ 1.run（URLClassLoader.java:217）过滤位于org.codehaus.classworlds.RealmClassLoader.loadClassDirect（RealmClassLoader）的java.lang.ClassLoader.loadClass（ClassLoader.java:321）java.net.URLClassLoader.findClass（URLClassLoader.java:205）上的.AccessController.doPrivileged（Native Method）的.java：195）在org.codehaus.classworlds.DefaultClassRealm.loadClass（DefaultClassRealm.java:255）在org.codehaus.classworlds.DefaultClassRealm.loadClass（DefaultClassRealm.java:274）在org.codehaus.classworlds.RealmClassLoader.loadClass（ RealmClassLoader.java:214）at java.lang.ClassLoader.loadClass（ClassLoader.java:266 ）org.mortbay.jetty.webapp.WebAppClassLoader.loadClass（WebAppClassLoader.java:401）org.mortbay.jetty.webapp.WebAppClassLoader.loadClass（WebAppClassLoader.java:363）... 66更多2011-07-11 17 ：49：00.016 :: WARN：嵌套在org.springframework.beans.factory.BeanCreationException：创建文件[/home/ankur/Desktop/app/target/classes/applicationContext.xml]中定义的名为'userService'的bean时出错： bean的实例化失败;嵌套异常是org.springframework.beans.BeanInstantiationException：无法实例化bean类[com.app.service.UserServiceImpl]：构造函数抛出异常;嵌套异常是java.lang.NoClassDefFoundError：org / jboss / util / file / ArchiveBrowser $ Filter：java.lang.ClassNotFoundException：org.jboss.util.file.ArchiveBrowser $ Filter at java.net.URLClassLoader $ 1.run（URLClassLoader . java：217）at java.security.AccessController.doPrivileged（Native Method）at java.net.URLClassLoader.findClass（URLClassLoader.java:205）at atorg.codehaus.classworlds.RealmClassLoader.loadClassDirect（RealmClassLoader.java:195）中的java.lang.ClassLoader.loadClass（ClassLoader.java:321）org.codehaus.classworlds.DefaultClassRealm.loadClass（DefaultClassRealm.java:255）at org .orghaus.classworlds.DefaultClassRealm.loadClass（DefaultClassRealm.java:274）位于org的java.lang.ClassLoader.loadClass（ClassLoader.java:266）的org.codehaus.classworlds.RealmClassLoader.loadClass（RealmClassLoader.java:214） . 位于org.mortbay.jetty.webapp.WebAppClassLoader.loadClass（WebAppClassLoader.java:363）的mortbay.jetty.webapp.WebAppClassLoader.loadClass（WebAppClassLoader.java:401）org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory（HibernatePersistence.java： 119）at javax.persistence.Persistence.createEntityManagerFactory（Persistence.java：83）at javax.persistence.Persistence.createEntityManagerFactory（Persistence.java:60）at com.app.service.UserServiceImpl . （UserServiceImpl.java:10）at sun .reflect.NativeConstructorAccessorImpl.newInstance0（娜（参见方法）at sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:57）at sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45）at java.lang.reflect.Constructor.newInstance（Constructor.java:532） org.springframework.beans.BeanUtils.instantiateClass（BeanUtils.java:100）org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate（SimpleInstantiationStrategy.java:61）at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory .instantiateBean（AbstractAutowireCapableBeanFactory.java:877）org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:839）org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:440））org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory $ 1.run（AbstractAutow） ireCapableBeanFactory.java:409）位于org.springframework.beans.factory.support的org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380）的java.security.AccessController.doPrivileged（Native Method） . org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（AbstractBeanFactory.java）中的org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton（DefaultSingletonBeanRegistry.java:222）中的AbstractBeanFactory $ 1.getObject（AbstractBeanFactory.java:264）：261）在org.springframework的org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:185）org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:164） . org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitializ中的beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons（DefaultListableBeanFactory.java:429） org.springframework上的org.springframework.context.support.AbstractApplicationContext.refresh（AbstractApplicationContext.java:380）org.springframework.web.context.ContextLoader.createWebApplicationContext（ContextLoader.java:255）中的ation（AbstractApplicationContext.java:728） org.springframework.web.context.ContextLoaderListener.contextInitialized中的.web.context.ContextLoader.initWebApplicationContext（ContextLoader.java:199）（ContextLoaderListen

2 回答

1
首先，您尝试通过JPA连接数据库，

1.您说您尝试通过JPA持久性API进行连接，因此不应该在持久性.xml文件中指定任何hbm文件 .

2.在服务类中，您尝试通过entitymanager访问数据，您没有提供/加载jast加载数据的persistence.xml . 正如我所看到您编写了一个getter / setter方法，所以你使用的是Spring吗？注入以注入entitymanager属性 .

所以我想首先看一下JPA部分并测试它然后用Struts2连接它 . 尝试使用此行创建entitymanager .
```
emf = Persistence.createEntityManagerFactory("MyJPAApplicationPU");
 em = emf.createEntityManager();
```
这里的“MyJPAApplicationPU”是持久性单元名称 . 它在persistence.xml文件中定义，为你的“APP” .
回复于 2024-05-07T16:56:21+08:00

Ok ankur，只提供你的应用程序上下文xml文件，当工厂无法在xml中加载任何bean id时，Actualy会发生此错误 .

有一件事我建议你使用接口注入，所以在你的UserServiceImpl中你需要注入所需的referance属性是entitymanager对象

你有没有像这样编写你的应用程序上下文

<bean
    class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

<bean id="userService" class="quickstart.service.UserServiceImpl" />

<bean id="entityManagerFactory"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="jpaVendorAdapter">
        <bean
            class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
            <property name="database" value="MYSQL" />
            <property name="showSql" value="true" />
        </bean>
    </property>
</bean>

<bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver" />
    <property name="url" value="jdbc:mysql://localhost/xyz" />
    <property name="username" value="root" />
    <property name="password" value="root" />
</bean>

<bean id="transactionManager"
    class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

2.如果是，那么在你的chek中你的 web.xml 上下文加载器

<listener>
    <listener-class>
        org.springframework.web.context.ContextLoaderListener
    </listener-class>
</listener>

3.还使用@PersistenceContext

@PersistenceContext

public void setEntityManager（EntityManager em）

回复于 2024-05-07T16:56:21+08:00

如何使用Hutsnate提供的struts2框架上的JPA扩展来访问数据库？

2 回答

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