2.建立一個專案：

① new--->Spring Stater project

②

③：搜尋需要的依賴包

④：我們發現上一步選擇的依賴，在pom.xml檔案中 已經自動新增到我們的檔案中了。

2. 開始編寫程式碼和一些配置

先看一下我的專案的最後目錄結構：

①：自己建立一個數據表  欄位為id ， name， password ，number 四個欄位   id為int型別，其他的都為String型別。

在src/main/java目錄下新增controller層，entity層，mapper層，service層

entity層的實體類User：

package com.example.demo.entity;

public class User {
	
	private int id;
	private String name;
	private String password;
	private String number;
	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 getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}
	

	public String getNumber() {
		return number;
	}

	public void setNumber(String number) {
		this.number = number;
	}



	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", password=" + password + ", number=" + number + "]";
	}


	
}
 

mapper層的UserMapper類：

package com.example.demo.mapper;

import java.util.List;

import org.apache.ibatis.annotations.Mapper;

import com.example.demo.entity.User;
@Mapper
public interface UserMapper {
	
	List<User> findUserByName(String name);
	
	public List<User> ListUser();
	
	public int insertUser(User user);
	
	public int delete(int id);
	
	public int Update(User user);
	
}
 

service層的實現類Userservice：

package com.example.demo.service;

import java.util.List;

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

import com.example.demo.entity.User;
import com.example.demo.mapper.UserMapper;



@Service
public class UserService {
	@Autowired
	private UserMapper userMapper;

	public List<User> findByName(String name) {
		return userMapper.findUserByName(name);
	}

	public User insertUser(User user) {
		userMapper.insertUser(user);
		return user;
	}
	public List<User> ListUser(){
		return	userMapper.ListUser();
	}
	
	
	public int Update(User user){
		return userMapper.Update(user);
	}
	
	public int delete(int id){
		return userMapper.delete(id);
	}
}
 

package com.example.demo.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import com.example.demo.entity.User;
import com.example.demo.service.UserService;


@RestController
@RequestMapping(value = "/CRUD", method = { RequestMethod.GET, RequestMethod.POST })
public class CRUD {
	@Autowired
	private UserService userservice;

	@RequestMapping(value = "/delete", method = RequestMethod.GET)
	public String delete(int id) {
		int result = userservice.delete(id);
		if (result >= 1) {
			return "刪除成功";
		} else {
			return "刪除失敗";
		}
	}

	@RequestMapping(value = "/update", method = RequestMethod.POST)
	public String update(User user) {
		int result = userservice.Update(user);
		if (result >= 1) {
			return "修改成功";
		} else {
			return "修改失敗";
		}

	}
	
	@RequestMapping(value = "/insert", method = RequestMethod.POST)
	public User insert(User user) {
		return userservice.insertUser(user);
		}
	
	@RequestMapping("/ListUser")
	@ResponseBody
	public List<User> ListUser(){
		return userservice.ListUser();
	}

	@RequestMapping("/ListUserByname")
	@ResponseBody
	public List<User> ListUserByname(String name){
		return userservice.findByName(name);
	}
}

接著：

在src/main/resources下寫UserMapper的對映檔案xml.

UserMapper.xml

<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE mapper PUBLIC
        "-//mybatis.org//DTD com.example.Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.mapper.UserMapper">
	<resultMap id="result" type="com.example.demo.entity.User">
		<result property="name" column="name" />
		<result property="password" column="password" />
		<result property="number" column="number"/>

	</resultMap>

	<select id="ListUser" resultMap="result">
		SELECT * FROM user
	</select>

	<select id="findUserByName" resultMap="result">
		SELECT * FROM user where name=#{name}
	</select>

	<insert id="insertUser" parameterType="com.example.demo.entity.User"
		keyProperty="id" useGeneratedKeys="true">
		INSERT INTO user
		(
		id,name,password,number
		)
		VALUES (
		#{id},
		#{name, jdbcType=VARCHAR},
		#{password, jdbcType=VARCHAR},
		#{number}
		)
	</insert>
	
	<delete id="delete" parameterType="int">
		delete from user where id=#{id}
	</delete>
	
	<update id="Update" parameterType="com.example.demo.entity.User">
	update user set user.name=#{name},user.password=#{password},user.number=#{number} where user.id=#{id}
	</update>
</mapper>

最後配置application.properties配置檔案：

spring.datasource.url = jdbc:mysql://localhost:3306/test
spring.datasource.username = root
spring.datasource.password = 11111111
spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.max-active=20
spring.datasource.max-idle=8
spring.datasource.min-idle=8
spring.datasource.initial-size=10
mybatis.mapper-locations= classpath:mapper/*.xml

啟動程式的入口類：SpringbootMybatisApplication.java

我們在postmain這個工具中測試：

測試根據name查詢資料：

測試根據Id刪除資料：

結束！原始碼地址-->碼雲：原始碼地址