idea+SpringBoot整合Mybatis完成增删改查功能

参考地址：https://blog.****.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