springboot--整合mybatis

转载：https://www.cnblogs.com/peterxiao/p/7779188.html

LZ今天自己搭建了下Spring boot+Mybatis，比原来的Spring+SpringMVC+Mybatis简单好多。其实只用Spring boot也可以开发，但是对于多表多条件分页查询，Spring boot就有点力不从心了，所以LZ把Mybatis整合进去，不得不说，现在的框架搭建真的是方便。话不多说，进入正题。

一、java web开发环境搭建

　　网上有很多教程，参考教程：http://www.cnblogs.com/Leo_wl/p/4752875.html 

二、Spring boot搭建

　　1、Intellij idea菜单栏File->new->project。

　　

　　2、选择左侧栏中spring initializr，右侧选择jdk版本，以及默认的Service URL，点击next。

　　

　　/3、然后填写项目的Group、Artifact等信息，helloworld阶段选默认就可以了，点击next。

　　

　　4、左侧点击Web，中间一侧选择Web，然后左侧选择SQL，中间一侧选择JPA、Mybatis、MYSQL（LZ数据库用的是mysql，大家可以选择其他DB），点击next。

　　

　　5、填写Project name 等信息，然后点击Finish。

　　

　　至此，一个maven web项目就创建好了，目录结构如下：

　　

这样，Spring boot就搭建好了，pom.xml里已经有了Spring boot的jar包，包括我们的mysql数据连接的jar包。Spring boot内置了类似tomcat这样的中间件，所以，只要运行DemoApplication中的main方法就可以启动项目了。我们测试一下。

在src/main/java下新建目录com/demo/entity/User。

package com.demo.entity;

public class User {
    private String name;

    public String getName() {
        return name;
    }

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

相同目录下新建com/demo/controller/TestBootController。

package com.demo.controller;

import com.demo.entity.User;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@EnableAutoConfiguration
@RequestMapping("/testboot")
public class TestBootController {
    @RequestMapping("getuser")
    public User getUser() {
        User user = new User();
        user.setName("test");
        return user;
    }
}

spring boot启动DemoAplication是需要扫描它下面的Controller等类的，所以将DemoApplication移动到com/demo目录下。还有就是Spring boot启动默认是要加载数据源的，所以我们在src/main/resources下新建application.yml：

#默认使用配置
spring:
  profiles:
    active: dev

#公共配置与profiles选择无关
mybatis:
  typeAliasesPackage: com.xdd.entity
  mapperLocations: classpath:mapper/*.xml


---

#开发配置
spring:
  profiles: dev

  datasource:
    url: jdbc:mysql://localhost:3306/test
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver

　　或者将pom.xml中加载数据源的jar包先注释掉也可以。

/*<dependency>
   <groupId>org.mybatis.spring.boot</groupId>
   <artifactId>mybatis-spring-boot-starter</artifactId>
   <version>1.3.0</version>
</dependency>*/

最终的目录结构如下，

启动DemoApplication的main方法，访问http://localhost:8080/testboot/getuser即可。

 三、整合Mybatis

　　1、集成druid，使用连接池。pom.xml中添加：

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.1.0</version>
</dependency>

　　最终的pom.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.arm</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.8.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>


        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.0</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

在application.yml中添加数据源、Mybatis的实体和配置文件位置。

#默认使用配置
spring:
  profiles:
    active: dev

#公共配置与profiles选择无关 mapperLocations指的路径是src/main/resources
mybatis:
  typeAliasesPackage: com.xdd.entity
  mapperLocations: classpath:mapper/*.xml


---

#开发配置
spring:
  profiles: dev

  datasource:
    url: jdbc:mysql://localhost:3306/test
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver
    # 使用druid数据源
    type: com.alibaba.druid.pool.DruidDataSource

就这样就整合完成了！我们测试一下。

用MyBatis Generator自动生成代码，参考博文：http://blog.csdn.net/zhshulin/article/details/23912615 这里列一下自动生成的代码。

import com.xdd.entity.User;
import org.springframework.stereotype.Component;

public interface UserDao {
    int deleteByPrimaryKey(Integer id);

    int insert(User record);

    int insertSelective(User record);

    User selectByPrimaryKey(Integer id);

    int updateByPrimaryKeySelective(User record);

    int updateByPrimaryKey(User record);
}

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.xdd.dao.UserDao" >
    <resultMap id="BaseResultMap" type="com.xdd.entity.User" >
        <id column="id" property="id" jdbcType="INTEGER" />
        <result column="user_name" property="userName" jdbcType="VARCHAR" />
        <result column="password" property="password" jdbcType="VARCHAR" />
        <result column="age" property="age" jdbcType="INTEGER" />
    </resultMap>
    <sql id="Base_Column_List" >
        id, user_name, password, age
    </sql>
    <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
        select
        <include refid="Base_Column_List" />
        from user_t
        where id = #{id,jdbcType=INTEGER}
    </select>
    <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
        delete from user_t
        where id = #{id,jdbcType=INTEGER}
    </delete>
    <insert id="insert" parameterType="com.xdd.entity.User" >
        insert into user_t (id, user_name, password,
        age)
        values (#{id,jdbcType=INTEGER}, #{userName,jdbcType=VARCHAR}, #{password,jdbcType=VARCHAR},
        #{age,jdbcType=INTEGER})
    </insert>
    <insert id="insertSelective" parameterType="com.xdd.entity.User" >
        insert into user_t
        <trim prefix="(" suffix=")" suffixOverrides="," >
            <if test="id != null" >
                id,
            </if>
            <if test="userName != null" >
                user_name,
            </if>
            <if test="password != null" >
                password,
            </if>
            <if test="age != null" >
                age,
            </if>
        </trim>
        <trim prefix="values (" suffix=")" suffixOverrides="," >
            <if test="id != null" >
                #{id,jdbcType=INTEGER},
            </if>
            <if test="userName != null" >
                #{userName,jdbcType=VARCHAR},
            </if>
            <if test="password != null" >
                #{password,jdbcType=VARCHAR},
            </if>
            <if test="age != null" >
                #{age,jdbcType=INTEGER},
            </if>
        </trim>
    </insert>
    <update id="updateByPrimaryKeySelective" parameterType="com.xdd.entity.User" >
        update user_t
        <set >
            <if test="userName != null" >
                user_name = #{userName,jdbcType=VARCHAR},
            </if>
            <if test="password != null" >
                password = #{password,jdbcType=VARCHAR},
            </if>
            <if test="age != null" >
                age = #{age,jdbcType=INTEGER},
            </if>
        </set>
        where id = #{id,jdbcType=INTEGER}
    </update>
    <update id="updateByPrimaryKey" parameterType="com.xdd.entity.User" >
        update user_t
        set user_name = #{userName,jdbcType=VARCHAR},
        password = #{password,jdbcType=VARCHAR},
        age = #{age,jdbcType=INTEGER}
        where id = #{id,jdbcType=INTEGER}
    </update>
</mapper>

public class User {
    private Integer id;

    private String userName;

    private String password;

    private Integer age;

    public Integer getId() {
        return id;
    }

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

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName == null ? null : userName.trim();
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password == null ? null : password.trim();
    }

    public Integer getAge() {
        return age;
    }

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

最后将DemoApplication.java修改一下，让其扫描dao层接口。

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.support.SpringBootServletInitializer;

@SpringBootApplication
@MapperScan("com.xdd.dao")
public class DemoApplication extends SpringBootServletInitializer{
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class,args);
    }
}

自己添加controller和service

import java.util.List;
import java.util.Map;

public interface UserService {
    public User getUserById(int userId);

    boolean addUser(User record);

}

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

import javax.annotation.Resource;
import java.util.List;
import java.util.Map;

@Service("userService")
public class UserServiceImpl implements UserService {

    @Resource
    private UserDao userDao;


    public User getUserById(int userId) {
        return userDao.selectByPrimaryKey(userId);
    }

    public boolean addUser(User record){
        boolean result = false;
        try {
            userDao.insertSelective(record);
            result = true;
        } catch (Exception e) {
            e.printStackTrace();
        }

        return result;
    }

}

@Controller
@RequestMapping("/user")
public class UserController {
    @Resource
    private UserService userService;

    @RequestMapping("/showUser")
    @ResponseBody
    public User toIndex(HttpServletRequest request, Model model){
        int userId = Integer.parseInt(request.getParameter("id"));
        User user = this.userService.getUserById(userId);
        return user;
    }

}

浏览器访问http://localhost:8080/user/showUser?id=1

以前找别人的教程的时候总是嫌弃人家写的不详细，真的自己写的时候发现很多细节我也详细介绍不到，比如yml文件使用，比如数据库，看来还是要求别人容易，要求自己难。