Java进阶知识27 SSH整合（Struts2、Spring、Hibernate）

1、我用到的jar包  

　　　　

2、整合实例  

2.1、MySQL数据库建表语句

create database school; -- 创建数据库
use school; -- 使用school数据库
4 create table user( -- 创建user表
  id int(4) primary key auto_increment,
  name varchar(20) not null,
  age int(4) not null
);
inert into user(name,age) values("张三",18);

2.2、配置web.xml文件

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
  <display-name></display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  
  <!-- Spring监听器 -->
  <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/classes/beans_*.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!-- Struts2过滤器 -->
    <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>

2.3、创建实体类（User）

package com.shore.entity;

/**
 * @author DSHORE/2019-11-12
 * 
 */
public class User {
    private Integer id;
    private String name;
    private Integer age;

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

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

    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
}

2.4、配置实体类User的hibernate文件（User.hbm.xml）

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
        
<hibernate-mapping package="com.shore.entity">
    <class name="User">  
        <id name="id"> 
            <generator class="native"/>
        </id>
        <property name="name" type="java.lang.String"/> 
        <property name="age" type="java.lang.Integer"/> 
    </class>
</hibernate-mapping>

2.5、创建dao层IUserDao接口类以及UserDao接口实现类

//接口类
public interface IUserDao {
    public User getByName(String name);//根据用户名查询
}

//对应的接口实现类
public class UserDao implements IUserDao {
    //从IoC容器注入SessionFactory
    private SessionFactory sessionFactory;
    public void setSessionFactory(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }
    
    @Override  //根据用户名查询
    public User getByName(String name) {
        Query query = sessionFactory.getCurrentSession().createQuery("from User where name=:name");  //:name是命名参数
        query.setParameter("name", name);
        @SuppressWarnings("unchecked")
        List<User> users = query.list();
        if (users != null && users.size() > 0) {
            return users.get(0);
        }
        return null;
    }
}

2.6、创建service层IUserService接口类以及UserService接口实现类

//接口类
public interface IUserService {
    public User getByName(String name);
}

//对应的接口实现类
public class UserService implements IUserService {

    private IUserDao userDao;
    public void setUserDao(IUserDao userDao) {
        this.userDao = userDao;
    }
    
    @Override
    public User getByName(String name) {
        return userDao.getByName(name);
    }
}

2.7、创建UserAction

package com.shore.action;

import com.opensymphony.xwork2.ActionSupport;
import com.shore.service.IUserService;

/**
 * @author DSHORE/2019-11-16
 *
 */
public class UserAction extends ActionSupport{
    private static final long serialVersionUID = -3099218232367860074L;
    
    private IUserService userService;
    
    public String login() {
        System.out.println(userService.getByName("张三"));
        return SUCCESS;
    }
    
    public void setUserService(IUserService userService) {
        this.userService = userService;
    }
}

2.8、配置Spring文件（beans_common.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: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/tx
       http://www.springframework.org/schema/tx/spring-tx.xsd
       http://www.springframework.org/schema/aop
       http://www.springframework.org/schema/aop/spring-aop.xsd">

    <!-- c3p0数据库连接池配置 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/school"></property>
        <property name="user" value="root"></property>
        <property name="password" value="root"></property>
        <property name="initialPoolSize" value="3"></property>
        <property name="maxPoolSize" value="100"></property>
        <property name="maxStatements" value="200"></property>
        <!--当连接池中的连接耗尽的时候c3p0一次同时获取的连接数。Default: 3 -->
        <property name="acquireIncrement" value="2"></property>
    </bean>

    <!-- Hibernate核心配置文件（hibernate.cfg.xml）全交给Spring去管理 -->
    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <!-- c3p0的数据库连接池 -->
        <property name="dataSource" ref="dataSource"></property>
        <!-- Hibernate基础参数配置 -->
        <property name="hibernateProperties">
            <props>  <!-- 注意：这个是Spring配置文件，故下面的key要写全名，即：前面加上hibernate.xxxxxx -->
                <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
                <prop key="hibernate.cache.provider_class">org.hibernate.cache.NoCacheProvider</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.format_sql">true</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
            </props>
        </property>
        <!-- Hibernate 映射文件的配置 -->
        <property name="mappingLocations">
            <list>
                <value>classpath:com/shore/entity/*.hbm.xml</value>
            </list>
        </property>
    </bean>

    <!-- dao层 -->
    <bean id="userDao" class="com.shore.dao.impl.UserDao">
        <property name="sessionFactory" ref="sessionFactory"></property>  
    </bean>
    
    <!-- service层 -->
    <bean id="userService" class="com.shore.service.impl.UserService">
        <property name="userDao" ref="userDao"></property>
    </bean>
    
    <!-- action层 -->
    <bean id="userAction" class="com.shore.action.UserAction" scope="prototype">
        <property name="userService" ref="userService"></property>
    </bean>
    
    <!-- ############Spring声明式事务管理配置########### -->
    <!-- 配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"></property>
    </bean>
    
    <!-- 配置事务增强(针对DAO层) -->
    <tx:advice transaction-manager="transactionManager" id="transactionAdvice">
        <tx:attributes>  <!-- *代表DAO层的所有方法 -->
            <tx:method name="*" read-only="false"/>
        </tx:attributes>
    </tx:advice>
    
    <!-- AOP配置:配置切入点表达式 -->
    <aop:config>    <!-- 第一个*表示返回值类型；第二个*表示service层下的所有接口实现类；第三个*表示每个接口实现类下的所有方法 -->
        <aop:pointcut expression="execution(* com.shore.service.impl.*.*(..))" id="pt"/>
        <aop:advisor advice-ref="transactionAdvice" pointcut-ref="pt"/>
    </aop:config>
</beans>

2.9、配置Struts2 文件（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>
    <!-- true支持动态方法调用 -->
    <constant name="struts.enable.DynamicMethodInvocation" value="true" />
    <constant name="struts.devMode" value="true" /> <!-- true -->


    <package name="user" namespace="/user" extends="struts-default">
        <action name="userAction" class="com.shore.action.UserAction">
            <result name="success">/success.jsp</result>
        </action>
    </package>
</struts>

测试结果图：

　　

总结：

  1、与传统方式相比，SSH框架 代码层（dao层、service层 等）耦合度较低，方便后期维护。

  2、entity、dao、service、action层、以及db层（连接数据库）都交给spring IOC容器来管理，大大降低各层之间的耦合度，极大方便该项目后期的维护。

  3、Hibernate或Spring IOC容器管理project与DB之间的连接；Spring IOC容器管理dao层（及BaseDao）、service层、action层；Struts2管理action层与前端页面的数据交互。

原创作者：DSHORE

作者主页：http://www.cnblogs.com/dshore123/

原文出自：https://www.cnblogs.com/dshore123/p/11874947.html

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