Spring（五）：Spring&Struts2&Hibernate整合后，实现查询Employee信息

• 背景：

　　基于之前两篇文章《Spring（三）：Spring整合Hibernate》、《Spring（四）：Spring整合Hibernate，之后整合Struts2》，了解了如何整合SSH的过程，但还不知道整合后在项目中该怎么开发使用，本文主要讲解的是基于SSH实现Employee信息查询功能的使用。

• 新建Employee,Department实体类，并添加对应类的hibernate实体配置文件

　　新建包com.dx.ssh.entities，在该包下创建Employee、Department实体类，并添加对应的hibernate实体配置文件Employee.hbm.xml、Department.hbm.xml

Employee.java

package com.dx.ssh.entities;

public class Department {
    private Integer id;
    private String deparmentName;

    public Integer getId() {
        return id;
    }

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

    public String getDeparmentName() {
        return deparmentName;
    }

    public void setDeparmentName(String deparmentName) {
        this.deparmentName = deparmentName;
    }
}

Employee.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2017-5-9 16:33:32 by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
    <class name="com.dx.ssh.entities.Department" table="SSH_DEPARTMENT">
        <id name="id" type="java.lang.Integer">
            <column name="ID" />
            <generator class="native" />
        </id>
        <property name="deparmentName" type="java.lang.String">
            <column name="DEPARMENTNAME" />
        </property>
    </class>
</hibernate-mapping>

Department.java

package com.dx.ssh.entities;

import java.util.Date;

public class Employee {
    private Integer id;
    private String lastName;
    private String email;
    private Date birth;
    // 不能被修改
    private Date createTime;
    // n:1的关系
    private Department department;

    public Integer getId() {
        return id;
    }

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

    public String getLastName() {
        return lastName;
    }

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

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Date getBirth() {
        return birth;
    }

    public void setBirth(Date birth) {
        this.birth = birth;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    public Department getDepartment() {
        return department;
    }

    public void setDepartment(Department department) {
        this.department = department;
    }
}

Department.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2017-5-9 16:33:32 by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
    <class name="com.dx.ssh.entities.Employee" table="SSH_EMPLOYEE">
        <id name="id" type="java.lang.Integer">
            <column name="ID" />
            <generator class="native" />
        </id>
        <property name="lastName" type="java.lang.String">
            <column name="LASTNAME" />
        </property>
        <property name="email" type="java.lang.String">
            <column name="EMAIL" />
        </property>
        <property name="birth" type="java.util.Date">
            <column name="BIRTH" />
        </property>
        <property name="createTime" type="java.util.Date">
            <column name="CREATETIME" />
        </property>
        <!-- 单项N:1关联关系 -->
        <many-to-one name="department" class="com.dx.ssh.entities.Department">
            <column name="DEPARTMENT_ID" />
        </many-to-one>
    </class>
</hibernate-mapping>

• 添加Dao、Service、Action，并配置相关配置文件

添加包com.dx.ssh.dao，并新建EmployeeDao.java

package com.dx.ssh.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;

import com.dx.ssh.entities.Employee;

public class EmployeeDao {
    private SessionFactory sessionFactory;

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

    private Session getSession() {
        return this.sessionFactory.getCurrentSession();
    }

    public List<Employee> getAll() {
        String hql = "From Employee e LEFT OUTER JOIN FETCH e.department";
        return getSession().createQuery(hql).list();
    }
}

在com.dx.ssh.service包下，新建EmployeeService.java

package com.dx.ssh.service;

import java.util.List;

import com.dx.ssh.dao.EmployeeDao;
import com.dx.ssh.entities.Employee;

public class EmployeeService {
    private EmployeeDao employeeDao;

    public void setEmployeeDao(EmployeeDao employeeDao) {
        this.employeeDao = employeeDao;
    }

    public List<Employee> getAll() {
        List<Employee> items = employeeDao.getAll();

        return items;
    }
}

在com.dx.ssh.actions下，新建Action类EmployeeAction.java

package com.dx.ssh.service;

import java.util.List;

import com.dx.ssh.dao.EmployeeDao;
import com.dx.ssh.entities.Employee;

public class EmployeeService {
    private EmployeeDao employeeDao;

    public void setEmployeeDao(EmployeeDao employeeDao) {
        this.employeeDao = employeeDao;
    }

    public List<Employee> getAll() {
        List<Employee> items = employeeDao.getAll();

        return items;
    }
}

配置applicationContext-beans.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
    <bean id="employeeDao" class="com.dx.ssh.dao.EmployeeDao">
        <property name="sessionFactory" ref="sessionFactory"></property>
    </bean>

    <bean id="employeeService" class="com.dx.ssh.service.EmployeeService">
        <property name="employeeDao" ref="employeeDao"></property>
    </bean>

    <bean id="employeeAction" class="com.dx.ssh.actions.EmployeeAction" scope="prototype">
        <property name="employeeService" ref="employeeService"></property>
    </bean>
</beans>

配置struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">
<struts>
    <constant name="struts.enable.DynamicMethodInvocation" value="false" />
    <constant name="struts.devMode" value="true" />

    <package name="default" namespace="/" extends="struts-default">
        <action name="emp-*" class="employeeAction" method="{1}">
            <result name="list">/WEB-INF/views/emp-list.jsp</result>
        </action>
    </package>
</struts>

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">

    <!-- 加载配置文件 -->
    <context:property-placeholder location="classpath:jdbc.properties" file-encoding="utf-8" ignore-unresolvable="true" />

    <!-- 配置数据源 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driverClassName}"></property>
        <property name="jdbcUrl" value="${jdbc.url}"></property>
        <property name="user" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
        <property name="testConnectionOnCheckout" value="${jdbc.c3p0.testConnectionOnCheckout}"></property>
        <property name="testConnectionOnCheckin" value="${jdbc.c3p0.testConnectionOnCheckin}"></property>
        <property name="idleConnectionTestPeriod" value="${jdbc.c3p0.idleConnectionTestPeriod}"></property>
        <property name="initialPoolSize" value="${jdbc.c3p0.initialPoolSize}"></property>
        <property name="minPoolSize" value="${jdbc.c3p0.minPoolSize}"></property>
        <property name="maxPoolSize" value="${jdbc.c3p0.maxPoolSize}"></property>
        <property name="maxIdleTime" value="${jdbc.c3p0.maxIdleTime}"></property>
    </bean>

    <bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
        <!-- 数据源dataSource -->
        <property name="dataSource" ref="dataSource" />

        <!-- hibernate的配置方案一  -->
        <property name="configLocation" value="classpath:hibernate.cfg.xml"></property>
        <!-- hibernate的配置方案二  -->
        <!-- 
        <property name="hibernateProperties"> 
            <props> 
                <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop> 
                <prop key="hibernate.dialect">${hibernate.dialect}</prop> 
                <prop key="hibernate.show_sql">${hibernate.show_sql}</prop> 
                <prop key="hibernate.format_sql">${hibernate.format_sql}</prop> 
                <prop key="hibernate.temp.use_jdbc_metadata_defaults">false</prop> 
            </props> 
        </property>
         -->

        <!-- 持久化类的位置方案一，通过包进行扫描 -->
        <property name="mappingLocations" value="classpath:com/dx/ssh/entities/*.hbm.xml"></property>
        <!-- spring的spring.jar的jar包内，在org.springframework.orm.hibernate3.annotation下， 
            有一个AnnotationSessionFactoryBean类，其中有一个属性叫做"packagesToScan"， 有个方法叫setpackagesToScan()，
        也就是说我可以再spring里面将这个属性给设定上。 
            packagesToScan是"包扫描"的意思，哪些包spring可以给我们扫描一下，看看有哪些实体类，
        这一项在我们在配置文件中配置hibernate的实体类的时候可以这么配，只要给出具体的扫描范围就可以了， 
        不需要将实体类一个一个的写出来 
        -->
        <!-- 持久化类的位置方案二，通过包进行扫描 -->
        <!-- 
        <property name="packagesToScan"> 
            <list> 
                <value>com.dx.ssh.entities</value> 
            </list> 
        </property> 
        -->
        <!-- 持久化类的位置方案三，通过类进行扫描 -->
        <!-- 
        <property name="annotatedClasses"> 
            <list> 
                <value>com.dx.ssh.entities.Member</value> 
                <value>com.dx.ssh.entities.Log</value> 
            </list> 
        </property> 
        -->
    </bean>
    <!-- 配置Hibernate事务管理器 -->
    <bean id="transactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>

    <!-- 配置事务异常封装
    <bean id="persistenceExceptionTranslationPostProcessor" class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />
     -->
    <!-- 基于数据源的事务管理器 -->
    <!-- 
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean> 
     -->
    <!-- 启用注解来管理事务 -->  
    
    <!-- 配合<tx:advice>和<aop:advisor>完成了事务切面的定义 -->
    <!-- 使用强大的切点表达式是语言轻松定义目标方法 -->
    <aop:config proxy-target-class="true">
        <!-- 通过aop定义事务增强切面 -->
        <aop:pointcut expression=" execution(* com.dx.ssh.service..*(..))" id="serviceMethod" />
        <!-- 引用事务增强 -->
        <aop:advisor advice-ref="txAdvice" pointcut-ref="serviceMethod" />
    </aop:config>
    <!-- 事务增强 -->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <!-- 事务属性定义 -->
        <tx:attributes>
            <tx:method name="*" />
        </tx:attributes>
    </tx:advice>
    
    <!-- 第一种方式: 注解方式配置事物 
    <tx:annotation-driven transaction-manager="transactionManager" />
    -->
</beans>

hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!--
        把一下配置信息转移到jdbc.properties中。
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">123456</property>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost/my_ssh</property>
        -->

        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
        <property name="hibernate.show_sql">true</property>
        <property name="hibernate.format_sql">true</property>
        <property name="hibernate.hbm2ddl.auto">update</property>
        <!-- <property name="hibernate.current_session_context_class">thread</property> -->
    </session-factory>
</hibernate-configuration>

jdbc.properties

#-----------------------------------------------------
# u6570u636Eu5E93u914Du7F6E
#-----------------------------------------------------
#u670Du52A1u5668u5730u5740
host=127.0.0.1
dbName=my_ssh
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://${host}:3306/${dbName}
jdbc.username=root
jdbc.password=123456

#-----------------------------------------------------
# u9002u7528u4E8Ec3p0u7684u914Du7F6E
#-----------------------------------------------------
#-----------------------------------------------------
# c3p0u53CDu7A7Au95F2u8BBEu7F6EuFF0Cu9632u6B628u5C0Fu65F6u5931u6548u95EEu989828800
#-----------------------------------------------------
#idleConnectionTestPeriodu8981u5C0Fu4E8EMySQLu7684wait_timeout
jdbc.c3p0.testConnectionOnCheckout=false
jdbc.c3p0.testConnectionOnCheckin=true
jdbc.c3p0.idleConnectionTestPeriod=3600
#-----------------------------------------------------
# c3p0u8FDEu63A5u6C60u914Du7F6E
#-----------------------------------------------------
#initialPoolSize, minPoolSize, maxPoolSize define the number of Connections that will be pooled.
#Please ensure that minPoolSize <= maxPoolSize.
#Unreasonable values of initialPoolSize will be ignored, and minPoolSize will be used instead.
jdbc.c3p0.initialPoolSize=10
jdbc.c3p0.minPoolSize=10
jdbc.c3p0.maxPoolSize=100
#maxIdleTime defines how many seconds a Connection should be permitted to go unused before being culled from the pool.
jdbc.c3p0.maxIdleTime=3600
#-----------------------------------------------------
# hibernateu8FDEu63A5u6C60u914Du7F6E
#-----------------------------------------------------
hibernate.connection.driverClass=com.mysql.jdbc.Driver
hibernate.connection.url=jdbc:mysql://${host}:3306/${dbName}
hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
hibernate.show_sql=true
hibernate.format_sql=true
hibernate.hbm2ddl.auto=update

在WebContent下创建index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<a href="emp-list">Employee List</a>
</body>
</html>

在WEB-INF下创建views文件夹，在views下创建emp-list.jsp页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    <s:if test="#request.employees==null || #request.employees.size()==0">
        暂无记录！
    </s:if>
    <s:else>
        <table border="1" cellpadding="10" cellspacing="0">
            <tr>
                <td>ID</td>
                <td>LastName</td>
                <td>Email</td>
                <td>BirthDay</td>
                <td>CreateTime</td>
                <td>Department Name</td>
            <tr>
                <s:iterator value="#request.employees">
                    <tr>
                        <td>${id }</td>
                        <td>${lastName }</td>
                        <td>${email }</td>
                        <td>${birth }</td>
                        <td>${createTime }</td>
                        <td>${department.deparmentName }</td>
                    <tr>
                </s:iterator>
        </table>
    </s:else>
</body>
</html>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID"
    version="3.0">
    <display-name>My-SSH</display-name>

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>index</welcome-file>
    </welcome-file-list>

      <!-- 配置启动IOC容器的Listener -->
    <!-- needed for ContextLoaderListener -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext*.xml</param-value>
    </context-param>

    <!-- Bootstraps the root web application context before servlet initialization -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    
    <!-- Struts2 filter -->
    <filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

</web-app>

项目结构如下：

• 测试结果：

• 常见抛出异常情况：

1、nested exception is java.lang.NoClassDefFoundError: org/aspectj/weaver/reflect/ReflectionWorld$ReflectionWorldException

错误原因:缺少aspectjweaver-1.8.9.jar包导致的错误。

从地址http://repo1.maven.org/maven2/org/aspectj/aspectjweaver/，下载包aspectjweaver-1.8.9.jar。

2、Action class [userAction] not found - action

在做一个 ssh三个框架集成的时候，经常遇到上诉问题。如果已经正确定义了action，仍报错，其实是缺少包struts2-sping-plugin 2.0.1.jar

 解决方案一: 

上诉问题说的 在struts.xml 没用找到 sping配置文件里的一个bean啊;也就是说：struts.xml 这个文件没有和sping配置文件关联起来；

在此 另一种解决方案是 在 lib 目录下加入一个jar包struts2-sping-plugin 2.0.1.jar问题就解决了.

解决方案二:

在struts.xml中还要加入这么一个bean 

<bean type="com.opensymphony.xwork2.ObjectFactory" name="spring" 
         class="org.apache.struts2.spring.StrutsSpringObjectFactory" />

这个bean要放在package的外面

3、Struts Problem Report

Struts has detected an unhandled exception:

Messages:	createQuery is not valid without active transaction
File:	org/hibernate/context/internal/ThreadLocalSessionContext.java
Line number:	351

解决方案：

包hibernate.cfg.xml中的配置项注意掉:

<!-- <property name="hibernate.current_session_context_class">thread</property> -->

4、hibernate中采用了lazy加载，在查询hql=“From Employee e”，执行过程中dao被service调用，当action调用employeeService结束后，就立即关闭了session，导致页面没有版本加载数据导致的错误。

 Struts Problem Report

Struts has detected an unhandled exception:

Messages:	could not initialize proxy - no Session Error reading 'deparmentName' on type com.dx.ssh.entities.Department_$$_jvst9ef_0 javax.el.ELException: Error reading 'deparmentName' on type com.dx.ssh.entities.Department_$$_jvst9ef_0
File:	org/hibernate/proxy/AbstractLazyInitializer.java
Line number:	146

解决该错误有三种解决方案：

解决方案一：修改Employee.hbm.xml man-to-one节点添加上属性 lazy="false",比较笨的方法。因为这是在用效率作为代价。

        <!-- 单项N:1关联关系 -->
        <many-to-one name="department" class="com.dx.ssh.entities.Department" lazy="false">
            <column name="DEPARTMENT_ID" />
        </many-to-one>

解决方案二：使用OpenSessionInViewFilter。这种方法是将session交给servlet filter来管理，每当一个请求来之后就会开

启一个session，只有当响应结束后才会关闭。如下：

<filter-name>hibernateFilter</filter-name>   
     <filter-class>  org.springframework.orm.hibernate3.support.OpenSessionInViewFilter </filter-class>   
</filter   
<filter-mapping>   
     <filter-name>hibernateFilter</filter-name>   
     <url-pattern>/*</url-pattern>   
</filter-mapping>   

解决方案三：修改hql

    public List<Employee> getAll() {
        String hql = "From Employee e LEFT OUTER JOIN FETCH e.department";
        return getSession().createQuery(hql).list();
    }

My-SSH项目源代码下载地址：http://pan.baidu.com/s/1o87Ezge