springboot系列（第四讲）

springboot整合mybatis
一、添加相关的依赖：

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.7.RELEASE</version>
    </parent>
    <dependencies>
    <!-- spring boot 支持mvc aop -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- springboot+mybatis -->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.1.1</version>
    </dependency>

    <!-- 数据库驱动 -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.39</version>
    </dependency>
    </dependencies>

二、编写程序主入口：

package com.sxnd;

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

@SpringBootApplication
@MapperScan("com.sxnd.mapper")//扫描包的注解
public class app {
    public static void main(String[] args) {
        SpringApplication.run(app.class,args);
    }
}

三、接下来就是实体类和mapper接口
pojo:

package com.sxnd.pojo;

public class User {
    private int id;
    private String username;
    private String password;

    public int getId() {
        return id;
    }

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

    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;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

UserMapper:(这里采用的是注解进行开发，配置文件在后面会进行详细的介绍)

package com.sxnd.mapper;

import com.sxnd.pojo.User;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;

import java.util.List;
@Repository
public interface UserMapper {
    @Select("select * from users")
    List<User> findAll();
}

四、service和controller层的开发：
service：

package com.sxnd.service.impl;

import com.sxnd.mapper.UserMapper;
import com.sxnd.pojo.User;
import com.sxnd.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

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

controller:

package com.sxnd.controller;

import com.sxnd.pojo.User;
import com.sxnd.service.UserService;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

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

@RestController
public class TestController {

    @Resource
    private UserService userService;

    @RequestMapping("find")
    public List<User> findAll(){
        List<User> list = userService.findAll();
        return list;
    }

}

五、配置文件的写法：
application.properties:

spring.datasource.url=jdbc:mysql://localhost:3306/mybatis
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
#mybaits.type-aliases-package=com.sxnd.pojo
#mybatis.mapper-locations = classpath:mapper/*Mapper.xml

六、由第五步可以看出，如果想用配置文件的形式写sql，该sql所在的位置已经不是在之前的mapper中了，现在全部都已经改到类路径下面了，如我所注释 的就是在类路径下的mapper目录下的*Mapper.xml文件。里面的写法和之前的mybatis中的写法一样。