Springboot从入门到精通(四)

Springboot整合mybatis

1.在pom中加入所需要的依赖：

<dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>${mybatis.spring.version}</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>

2.在application.yml中配置数据源和mybatis的相关信息

#数据源
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/cfcc_pt
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver

#mybatis
mybatis:
  typeAliasesPackage: com.cfcc.pojo
  mapperLocations: classpath:mybatis/*.xml

3.在启动类的上面加上mapper扫描器，扫描所引用的包。

@SpringBootApplication
@RestController
@MapperScan("com.cfcc.mapper")
public class CfccApplicaton {
    public static void main(String[] args) {
        SpringApplication.run(CfccApplicaton.class, args);
    }

}

4.在数据库中新建一张user表

CREATE TABLE `cf_user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) NOT NULL,
  `age` int(11) DEFAULT NULL,
  `addr` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;

5.新建一个与用户对应的实体类

package com.cfcc.pojo;

public class CfUser {
    private int id;
    private String name;
    private int age;
    private String addr;

    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 int getAge() {
        return age;
    }

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

    public String getAddr() {
        return addr;
    }

    public void setAddr(String addr) {
        this.addr = addr;
    }
}

6.在resources下新建mybatis目录并在下面新建一个userMapper.xml。

在xml编写一些简单的针对用户的增删改查的方法。

<?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.cfcc.mapper.UserMapper" >
	<select id="findUserById" parameterType="int" resultType="cfUser">
		SELECT * from cf_user where id=#{id}
	</select>
	<select id="findUserListByName" resultType="cfUser">
		SELECT * from cf_user
	</select>
	<!-- 插入并返回自增主键 -->
	<insert id="insertUser" parameterType="cfUser" useGeneratedKeys="true" keyProperty="id">
		insert INTO cf_user(name, age, addr) VALUES (#{name},#{age},#{addr})
	</insert>
	<update id="updateUser" parameterType="cfUser">
		UPDATE cf_user set name=#{name},age=#{age},addr=#{addr}
		where id=#{id}
	</update>
	<delete id="deleteUserById" parameterType="int">
		delete from cf_user where id=#{id}
	</delete>

</mapper>

7.新建UserMapper接口，并编写对应的方法。

package com.cfcc.mapper;

import com.cfcc.pojo.CfUser;

import java.util.List;

public interface UserMapper {
    CfUser findUserById(int id);
    List<CfUser> findUserListByName();
    void insertUser(CfUser cfUser);
    void updateUser(CfUser cfUser);
    void deleteUserById(int id);
}

8.在controller中编写方法调用mapper，使用简单的restful风格的url。

package com.cfcc.controller;

import com.cfcc.mapper.UserMapper;
import com.cfcc.pojo.CfUser;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/rest")
public class UserRestController {
    @Autowired
    private UserMapper mapper;

    @RequestMapping(value = "/", method = RequestMethod.GET)
    public List<CfUser> getUserList(){
        List<CfUser> list = mapper.findUserListByName();
        return list;
    }

    @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    public CfUser getUserById(@PathVariable int id){
        CfUser user = mapper.findUserById(id);
        return user;
    }

    @RequestMapping(value = "/", method = RequestMethod.POST)
    public CfUser postUser(){
        CfUser user = new CfUser();
        user.setName("张三");
        user.setAge(23);
        user.setAddr("北京");
        mapper.insertUser(user);
        return user;
    }
    @RequestMapping(value = "/{id}", method = RequestMethod.PUT)
    public String putUser(@PathVariable int id){
        CfUser user = new CfUser();
        user.setName("王五");
        user.setAge(24);
        user.setAddr("广州");
        user.setId(id);
        mapper.updateUser(user);
        return "put success";
    }
    @RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
    public String deleteUser(@PathVariable int id){
        mapper.deleteUserById(id);
        return "delete success";
    }

}

启动工程，即可在浏览器中访问对应的url。