MyBatis 与 Spring 以及 Spring MVC 的整合

与 Spring4.3 的集成

上一篇文章 Mybatis 基于 Web 应用的使用 中，我们在 Web 应用中使用了 Mybatis，并了解了 Mybatis 的基本用法和相关的类，在接下来的内容中，我们会将原先由 Mybatis 完成的工作转移到 Spring 中，由 Spring 做整合的工作。

Spring 处理的核心内容：

• 加载 MyBatis Factory 类和 session 类，我们不再需要自己去创建 SqlSessionFactory 和 SqlSession 实例了，同一由 Spring 帮我们创建。
• Spring 提供一个简单的方式来注入 MyBatis 数据映射器（XxxMapper）和 SqlSession 到业务层的 bean 中。

修改 Web 项目

我们可以在上一篇文章的项目基础上进行修改，保留 User.java，UserMapper.java，mybatis.xml，UserMapper.xml 四个文件，数据库不变。

schema.sql

CREATE TABLE `user` (
	`id` INT(11) NOT NULL AUTO_INCREMENT,
	`name` VARCHAR(30) DEFAULT NULL,
	`address` VARCHAR(255) DEFAULT NULL,
	PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `user` (`name`, `address`) VALUES ('Leo', 'GuangDong HuiZhou');
INSERT INTO `user` (`name`, `address`) VALUES ('Dan', 'GuangDong ShanTou');

User.java

package com.lake.model;

public class User {

    private int id;
    private String name;
    private String address;

    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 getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}

UserMapper.java

package com.lake.mapper;

import java.util.List;

import com.lake.model.User;

public interface UserMapper {
    public User selectUserByID(int id);
    public List<User> selectUsersByName(String name);
    public void addUser(User user);
    public void updateUser(User user);
    public void deleteUser(int id);
}

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.lake.mapper.UserMapper">
    <select id="selectUserByID" parameterType="int" resultType="User">
        select * from `user` where id = #{id}
    </select>

    <!-- 为了返回list 类型而定义的returnMap -->
    <resultMap type="User" id="resultListUser">
        <id column="id" property="id" />
        <result column="name" property="name" />
        <result column="address" property="address" />
    </resultMap>

    <!-- 返回list 的select 语句，注意 resultMap 的值是指向前面定义好的 -->
    <select id="selectUsersByName" parameterType="string" resultMap="resultListUser">
        select * from user where name like #{name}
    </select>

    <!-- useGeneratedKeys为true时，表示自动获取数据库生成的主键值；
        keyProperty="id"表示将获取的主键值主要到User的属性id中 -->
    <insert id="addUser" parameterType="User" useGeneratedKeys="true"
        keyProperty="id">
        insert into user (name, address) values (#{name}, #{address})
    </insert>

    <update id="updateUser" parameterType="User">
        update user set name=#{name}, address=#{address} where id=#{id}
    </update>

    <delete id="deleteUser" parameterType="int">
        delete from user where id=#{id}
    </delete>
</mapper>

在 pom.xml 中添加依赖

<properties>
    <!-- spring 版本号 -->
    <spring.version>4.3.4.RELEASE</spring.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <!-- spring 包 -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-beans</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aop</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc-portlet</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>aopalliance</groupId>
        <artifactId>aopalliance</artifactId>
        <version>1.0</version>
    </dependency>

    <!-- mybatis 包 -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.1</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.3.0</version>
    </dependency>
    <!-- mysql驱动包 -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.40</version>
    </dependency>

    <!-- JSTL -->
    <dependency>
        <groupId>taglibs</groupId>
        <artifactId>standard</artifactId>
        <version>1.1.2</version>
    </dependency>
    <dependency>
        <groupId>jstl</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>

    <!-- apache 工具包 -->
    <dependency>
        <groupId>commons-dbcp</groupId>
        <artifactId>commons-dbcp</artifactId>
        <version>1.4</version>
    </dependency>
    <dependency>
        <groupId>commons-collections</groupId>
        <artifactId>commons-collections</artifactId>
        <version>3.2.2</version>
    </dependency>

    <!-- 单元测试 -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>

    <!-- log4j 日志包 -->
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
</dependencies>

<build>
    <finalName>mybatis-spring-mvc</finalName>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

移除 Mybatis 配置文件的内容

原先这里的数据源和 mapper 映射器都交由 Spring 进行注入。

<?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>
    <typeAliases>
        <typeAlias alias="User" type="com.lake.model.User" />
    </typeAliases>
</configuration>

添加 Spring 配置文件

在 resources 目录下建立 applicationContext.xml 文件：

<?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"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="  
        http://www.springframework.org/schema/context  
        http://www.springframework.org/schema/context/spring-context-4.3.xsd  
        http://www.springframework.org/schema/beans  
        http://www.springframework.org/schema/beans/spring-beans-4.3.xsd">

    <!-- 采用 DBCP 连接池，需把 DBCP 的 jar 包导入到项目中 -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url"
        value="jdbc:mysql://127.0.0.1:3306/mybatis?characterEncoding=utf8" />
        <property name="username" value="root" />
        <property name="password" value="root" />
    </bean>

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- dataSource 属性指定要用到的连接池 -->
        <property name="dataSource" ref="dataSource" />
        <!-- configLocation 属性指定 mybatis 的核心配置文件 -->
        <property name="configLocation" value="mybatis.xml" />
    </bean>

    <bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <!-- sqlSessionFactory 属性指定要用到的 SqlSessionFactory 实例 -->
        <property name="sqlSessionFactory" ref="sqlSessionFactory" />
        <!-- mapperInterface 属性指定映射器接口，用于实现此接口并生成映射器对象 -->
        <!-- 映射器类必须是一个接口，不能是一个具体的实现类 -->
        <property name="mapperInterface" value="com.lake.mapper.UserMapper" />
    </bean>
</beans>

测试内容

在 src/test/java 目录下新建测试类：

package com.lake.test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.lake.mapper.UserMapper;
import com.lake.model.User;

public class SpringTest {

    private static ApplicationContext ctx;

    static {
        ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
    }

    public static void main(String[] args) {
        UserMapper userMapper = (UserMapper) ctx.getBean("userMapper");
        User user = userMapper.selectUserByID(1);
        System.out.println(user.getName() + ": " + user.getAddress());
    }
}

测试结果

Leo: GuangDong ChaoZhou

与 Spring MVC 的集成

配置 web.xml

配置 spring dispatchservlet 和 Spring 配置文件的位置，以及监听器。

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
    id="WebApp_ID" version="3.1">
    <display-name>Archetype Created Web Application</display-name>

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

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

    <!-- 配置 spring dispatchservlet -->
    <servlet>
        <servlet-name>user</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>user</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

配置 dispatcher-servlet.xml

在 web.xml 同目录下配置 user-servlet.xml 文件，这个文件名前面部分必须与 web.xml 里面配置的 DispatcherServlet 的 servlet-name 一致。

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    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-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/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd">

    <context:component-scan base-package="com.lake.web" />
    <mvc:annotation-driven />

    <mvc:resources mapping="/static/**" location="/WEB-INF/static/" />
    <mvc:default-servlet-handler />

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix">
            <value>/WEB-INF/</value>
        </property>
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>
</beans>

配置 applicationContext.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" xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="  
    http://www.springframework.org/schema/context  
    http://www.springframework.org/schema/context/spring-context-4.3.xsd  
    http://www.springframework.org/schema/beans  
    http://www.springframework.org/schema/beans/spring-beans-4.3.xsd">

    <!-- 采用 DBCP 连接池，需把 DBCP 的 jar 包导入到项目中 -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
        destroy-method="close" p:driverClassName="com.mysql.jdbc.Driver"
        p:url="jdbc:mysql://127.0.0.1:3306/mybatis?characterEncoding=utf8"
        p:username="root" p:password="root" p:maxActive="10" p:maxIdle="10">
    </bean>

    <bean id="transactionManager"
        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource" />
    </bean>

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- dataSource 属性指定要用到的连接池 -->
        <property name="dataSource" ref="dataSource" />
        <!-- configLocation 属性指定 mybatis 的核心配置文件 -->
        <property name="configLocation" value="classpath:mybatis.xml" />
        <!-- 一次性加载所有配置的 mapper 文件，不需要一条一条加载 -->
        <property name="mapperLocations" value="classpath*:com/lake/mapper/*.xml" />
    </bean>

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

编写 Controller 类

package com.lake.web;

import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
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.lake.mapper.UserMapper;
import com.lake.model.User;

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

    @Autowired
    private UserMapper userMapper;

    @RequestMapping("/list")
    public ModelAndView listAll(HttpServletRequest request, HttpServletResponse response) {
        List<User> users = userMapper.selectUsersByName("%");
        ModelAndView mav = new ModelAndView("list");
        mav.addObject("users", users);
        return mav;
    }
}

编写 JSP 页面

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!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>User List</title>
</head>
<body>
    <c:forEach items="${users}" var="user">  
        ${user.id }--${user.name }--${user.address }<br />
    </c:forEach>
</body>
</html>

运行结果