spring、springmvc、mybatis整合笔记

　这段时间上一个项目刚做完，下一个项目还没开始，趁这个时候来认真总结一下上个项目使用的ssm开发框架。由于，项目中关于使用ssm这部分的代码和配置是我们项目的整体架构师一个独立完成的，我们只负责业务部分的代码，调用他写好的后台，所以涉及到ssm具体使用的我都没参与，之前简单的做过s（struts）sh，对于ssm不是很熟悉，所以，这段时间从头到尾独立搭建一个ssm框架的web应用。

　　首先，spring、springmvc、mybatis所需要的jar包准备好，导入到新建web项目的lib中，然后开始搭建java源代码（src）下的结构，我在这里用到的是类似ssh的结构mapper.java、mapper.xml、dao、daoImpl、service、serviceImpl、controller。项目目录结构如下。

　　接下来，写配置文件。

　　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" 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" id="WebApp_ID" version="3.0">
  <display-name>SSM</display-name>

  <!-- spring配置文件加载 -->
  <context-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:resources/spring-config.xml</param-value>
  </context-param>

  <!-- Spring ApplicationContext 载入 -->
  <listener>
      <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>

  <!-- mvc控制器 -->
  <servlet>
      <servlet-name>dispatcher</servlet-name>
      <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      <init-param>
          <param-name>contextConfigLocation</param-name>
            <param-value>
                classpath:resources/mvc-config.xml
            </param-value>
      </init-param>
      <load-on-startup>1</load-on-startup>
  </servlet>

  <servlet-mapping>
      <servlet-name>dispatcher</servlet-name>
      <url-pattern>*.do</url-pattern>
  </servlet-mapping>

  <!-- 默认显示的首页面 -->
  <welcome-file-list>
    <welcome-file>login.html</welcome-file>
    <welcome-file>login.jsp</welcome-file>
  </welcome-file-list>
</web-app>

-----------------------------------------------spring.xml--------------------------------------

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:context="http://www.springframework.org/schema/context"
    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
    http://www.springframework.org/schema/aop
    http://www.springframework.org/schema/aop/spring-aop.xsd
    http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context.xsd">

    <!-- 扫描DAO和SERVICE包，controller包在springmvc中扫描 -->
    <context:component-scan base-package="com.liusk.serviceImpl,com.liusk.daoImpl" />

    <!-- 数据源 -->
    <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/ssm?characterEncoding=utf-8"></property>
        <property name="user" value="root"></property>
        <property name="password" value="java"></property>
        <property name="minPoolSize" value="5"></property>
        <property name="maxPoolSize" value="100"></property>
    </bean>

    <!-- 会话工厂 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="configLocation" value="classpath:resources/mybatis-config.xml"></property>
        <property name="mapperLocations" value="classpath:com/liusk/mapper/*.xml"></property>
    </bean>

    <!-- 事务处理 -->
    <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    <tx:advice id="txAdvice" transaction-manager="txManager">
        <tx:attributes>
            <tx:method name="insert*" propagation="REQUIRED"></tx:method>
            <tx:method name="delete*" propagation="REQUIRED"></tx:method>
            <tx:method name="update*" propagation="REQUIRED"></tx:method>
            <tx:method name="select*" propagation="SUPPORTS"></tx:method>
        </tx:attributes>
    </tx:advice>
    <aop:config>
        <aop:pointcut id="serviceCut" expression="execution(public * com.liusk.service.*.*(..))" />
        <aop:advisor pointcut-ref="serviceCut" advice-ref="txAdvice" />
    </aop:config>

    <!-- spring和mybatis的整合 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.liusk.mapper"/>
    </bean>

</beans>

　　关于spring和mybatis整合的方法有很多种，上面xml中是最基础的配置，还可以加入其它的限制条件，这个可以单独到百度上搜更详细的解释。

-------------------------------------------------------mvc-config.xml------------------------------------------------

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    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-3.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <!-- 扫描controller包 -->
    <context:component-scan base-package="com.liusk.controller"></context:component-scan>

    <!-- 完成请求和注解POJO的映射 -->
    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>

    <!-- 页面转向解析 -->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/" />
        <property name="suffix" value=".jsp" />
    </bean>

    <!-- 支持文件上传 -->
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    </bean>

</beans>

　　在mvcconfig中，最重要的工作是控制转发，这个配置文件中做了最简单的转发操作，只能转发页面，如果想要通过ajax实现转发数据，那么需要重写ViewResolver来实现这个功能。

--------------------------------------------------------mybatis-config.xml-------------------------------------

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <!-- 定义别名 -->
    <typeAliases>
        <typeAlias type="com.liusk.entity.User" alias="User"/>
    </typeAliases>

</configuration>

　　至此，配置文件部分完毕。

　　下面是src源码

----------------------------------------------------------User.java------------------------------------------------------

package com.liusk.entity;

public class User {
    private String userId;
    private String username;
    private String password;

    public String getUserId() {
        return userId;
    }
    public void setUserId(String userId) {
        this.userId = userId;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
}

　　mybatis的实体类和hibernate实体类的不同是mybatis的实体类不需要加载到spring的beanFactory中，而是通过操作数据库的mapper来持久化数据。

-----------------------------------------------------------UserMapper.java------------------------------------------

package com.liusk.mapper;

import java.util.List;

import com.liusk.entity.User;

public interface UserMapper {
    public List<User> selectUser(User user);
    public void insertUser(User user);
    public List<User> selectUserByUserName(String username);
}

　　UserMapper.java这个文件是在何时被加载到spring中的呢？我们知道它是在daoImpl中使用到的，而且是注解到daoImpl中的，所以它一定在之前已经被加载到beanFactory中了，我在第一次配置的时候也不是太清楚它是什么时候进入beanFactory因为它身上没有任何注解，所以，根据spring配置文件中spring和mybatis的整合，推测UserMapper.java就是在

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.liusk.mapper"/></bean>

这个地方被加载的。这个下面有详细解答。

----------------------------------------------------------UserMapper.xml------------------------------------------

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.liusk.mapper.UserMapper">

    <resultMap type="com.liusk.entity.User" id="userMap">
        <id column="user_id" property="userId" ></id>
        <result column="user_name" property="username"/>
        <result column="password" property="password"/>
    </resultMap>

    <select id="selectUser" parameterType="User" resultType="java.util.List" resultMap="userMap">
        select * from user where user_name = #{username} and password = #{password}
    </select>

    <select id="selectUserByUserName" parameterType="java.lang.String" resultType="java.util.List" resultMap="userMap">
        select * from user where user_name = #{username}
    </select>

    <insert id="insertUser" parameterType="User">
        insert into user values (#{userId},#{username},#{password})
    </insert>

</mapper>

　　该配置文件中namespace对应接口的路径，也就是mapper.java的路径，否则抛出异常。所以这里牵涉到一个问题：UserMapper.java到底是何时加载到beanFactory的？为什么会用这个问题呢，应为UserMapper.xml在spring的sessionFactory初始化的时候被扫描并加载到spring，那么这个时候会不会根据这个命名空间同时把UserMapper.java加载到beanFactory中呢，其实我没有看过spring和mybatis的源码，所以不太了解。根据猜测和验证，UserMapper.java不是在这个时候被加载的。

------------------------------------------------------UserDAO--------------------------------------------

package com.liusk.dao;

import java.util.List;

import com.liusk.entity.User;

public interface UserDAO {

    public List<User> selectUser(User user);

    public void insertUser(User user);

    public List<User> selectUserByUserName(String username);
}

这个UserDAO的存在就是在向我的第一个项目使用ssh致敬的，其实这个UserDAO他就是个接口，可以不存在，下面的UserService也是这个道理。

------------------------------------------------------UserDAOImpl----------------------------------------

package com.liusk.daoImpl;

import java.util.List;

import org.safehaus.uuid.UUIDGenerator;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.liusk.dao.UserDAO;
import com.liusk.entity.User;
import com.liusk.mapper.UserMapper;

@Repository
public class UserDAOImpl implements UserDAO {

    @Autowired
    private UserMapper userMapper;

    private UUIDGenerator uuidGen = UUIDGenerator.getInstance();

    @Override
    public List<User> selectUser(User user) {
        return userMapper.selectUser(user);
    }

    @Override
    public void insertUser(User user) {
        String userId = uuidGen.generateTimeBasedUUID().toString();
        if(user.getUserId()==null||user.getUserId()=="")
            user.setUserId(userId.replace("-", ""));
        System.out.println(user.getUserId());
        userMapper.insertUser(user);
    }

    @Override
    public List<User> selectUserByUserName(String username) {
        return userMapper.selectUserByUserName(username);
    }

}

UserDAOImpl和UserServiceImpl类似，都是实现类，做具体的数据持久化操作。

--------------------------------------------------------UserService-----------------------------------------

package com.liusk.service;

import java.util.List;

import com.liusk.entity.User;

public interface UserService {

    public void insertUser(User user);

    public List<User> selectUser(User user);

    public boolean existUser(String username);

}

--------------------------------------------------------UserServiceImpl--------------------------------------

package com.liusk.serviceImpl;

import java.util.List;

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

import com.liusk.dao.UserDAO;
import com.liusk.entity.User;
import com.liusk.service.UserService;

@Service
public class UserServiceImpl implements UserService{

    @Autowired
    private UserDAO userDAO;

    @Override
    public void insertUser(User user) {
        userDAO.insertUser(user);
    }

    @Override
    public List<User> selectUser(User user) {
        return userDAO.selectUser(user);
    }

    @Override
    public boolean existUser(String username) {
        List<User> userList = userDAO.selectUserByUserName(username);
        if(userList.size()>0)
            return true;
        else
            return false;
    }

}

-------------------------------------------------------UserController-------------------------------------

package com.liusk.controller;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

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

import com.liusk.base.UserCounts;
import com.liusk.entity.User;
import com.liusk.service.UserService;

@Controller
@RequestMapping("user")
public class UserController {

    @Autowired
    private UserService userService;

    @SuppressWarnings("rawtypes")
    @RequestMapping("login.do")
    public ModelAndView login(String username,String password,HttpServletRequest request){
        User user = new User();
        user.setUsername(username);
        user.setPassword(password);
        List<User> userList = userService.selectUser(user);
        if(userList.size()>0){
            request.setAttribute("userList", userList);return new ModelAndView("index");
        }else
            return new ModelAndView("login");
    }

    @RequestMapping("regist.do")
    public ModelAndView regist(String username,String password,HttpServletRequest request){
        User user = new User();
        user.setUsername(username);
        user.setPassword(password);
        boolean flag = true;
        flag = userService.existUser(username);
        if(!flag)
            userService.insertUser(user);
        return new ModelAndView("login");
    }
}

　　至此，src下的java源码完毕。

　　下面是jsp页面部分。

-----------------------------------------------------login.jsp--------------------------------------------------

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>

<%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<base href=" <%=basePath%>">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>登录页面</title>

</head>
<body>
<div>
    <div>
        <form action="user/login.do" method="post">
            <label>用户名：</label>
            <input type="text" name="username" />
            <label>密码:</label>
            <input type="password" name="password"/>
            <button type="submit">登录</button>
            <button type="reset" >重置</button>
        </form>
    </div>

</div>

</body>
</html>

-----------------------------------------------------index.jsp--------------------------------------------------------

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ page import="com.liusk.entity.User" %>
<%@ page import="java.util.List" %>

<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<%
    List<User> userList = (List<User>)request.getAttribute("userList");%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<base href=" <%=basePath%>"/>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>index</title>
</head>
<body>
<div>
    <p>欢迎<%=userList.get(0).getUsername() %>!</p>
</div>
<div align="center" style="width:200;height:200">
    <form action="user/regist.do" method="post">
        <input type="text" name="username"/>
        <input type="text" name="password"/>
        <button type="submit">提交</button>
        <button type="reset">重置</button>
    </form>
</div>
</body>
</html>

　　jsp你懂得，这些页面就不做多解释。

　　总结，会用框架不难，难的是写一个框架出来，有梦就要勇敢飞。