参考地址：https://blog.csdn.net/baidu_36216018/article/details/79466935
1.idea创建spring boot项目
2.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.example</groupId>
<artifactId>shujuku</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>shujuku</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.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>
<!-- web -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- mybatis -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.1</version>
</dependency>
<!-- mysql -->
<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>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
3.项目目录结构：
4.表:表名：user
自己创建一个数据表 字段为id ， name， password ，number 四个字段 id为int类型，其他的都为String类型。
5.在src/main/java目录下添加controller层，entity层，mapper层，service层
entity层的实体类User：
package com.example.shujuku.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层的UserMapper类：
package com.example.shujuku.mapper;
import java.util.List;
import com.example.shujuku.entity.User;
import org.apache.ibatis.annotations.Mapper;
@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层的实现类Userservice：
package com.example.shujuku.service;
import java.util.List;
import com.example.shujuku.entity.User;
import com.example.shujuku.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class UserService {
@Autowired
public 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);
}
}
controller层 的访问类CRUD:
package com.example.shujuku.controller;
import java.util.List;
import com.example.shujuku.entity.User;
import com.example.shujuku.service.UserService;
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;
@RestController
@RequestMapping(value = "/crud", method = { RequestMethod.GET, RequestMethod.POST })
public class CRUD {
@Autowired
private UserService userservice;
@RequestMapping("/ListUser")
@ResponseBody
public List<User> ListUser(){
return userservice.ListUser();
}
@RequestMapping("/ListUserByname")
@ResponseBody
public List<User> ListUserByname(String name){
return userservice.findByName(name);
}
@RequestMapping(value = "/delete", method = RequestMethod.GET)
public String delete(int id) {
int result = userservice.delete(id);
if (result >= 1) {
return "删除成功";
} else {
return "删除失败";
}
}
@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 "修改失败";
}
}
@RequestMapping(value = "/insert", method = RequestMethod.POST)
public User insert(User user) {
return userservice.insertUser(user);
}
}
接着：
在src/main/resources下写UserMapper的映射文件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.shujuku.mapper.UserMapper">
<resultMap id="result" type="com.example.shujuku.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.shujuku.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.shujuku.entity.User">
update user set user.name=#{name},user.password=#{password},user.number=#{number} where user.id=#{id}
</update>
</mapper>
最后配置application.properties配置文件：
spring.datasource.url = jdbc:mysql://localhost:3306/world spring.datasource.username = root spring.datasource.password = 123456 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
启动程序的入口类：SpringbootMybatisApplication.java
测试查询所有的信息：http://localhost:8080/CRUD/ListUser