SpringBoot整合Mybatis实现CRUD

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.7.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>
  <groupId>com.beilin</groupId>
  <artifactId>SpringBoot-Mybatis</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>SpringBoot-Mybatis</name>
  <description>Demo project for Spring Boot</description>

  <properties>
    <java.version>1.8</java.version>
  </properties>
  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!--导入mybatis依赖-->
    <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>2.1.0</version>
    </dependency>

    <!--导入mysql依赖-->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.47</version>
    </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>
pom.xml

#配置mybatis

#配置xml映射路径
mybatis.mapper-locations=classpath:mapping/*.xml
#配置实体类别名
mybatis.type-aliases-package=com.beilin.entity
#开启驼峰命名法
mybatis.configuration.map-underscore-to-camel-case=true

#配置Mysql连接
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

package com.beilin;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan(value = "com.beilin.mapper")
@SpringBootApplication
public class SpringbootApplication {
  public static void main(String[] args) {
    SpringApplication.run(SpringbootApplication.class, args);
  }
}
SpringbootApplication

package com.beilin.entity;

public class User {
  /**
   * name:学生实体
   */

  //主键id
  private int id;
  //姓名
  private String name;
  //年龄
  private int age;

  // Get和 Set方法
  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;
  }
}

User.java

package com.beilin.mapper;
import com.beilin.entity.User;
import java.util.List;
public interface UserMapper {
   //插入
  public void insert(User user);
  //根据id删除
  public void delete(Integer id);
   //根据user的id修改
  public void update(User user);
  //根据id查询
  public User getById(Integer id);
  //查询全部
  public List<User> list();
}
UserMapper.java

<?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.beilin.mapper.UserMapper">
  <!-- 插入一个user -->
  <insert id="insert" parameterType="user">
  insert into user(name,age) values(#{name},#{age})
  </insert>
  <!-- 根据id删除学生 -->
  <delete id="delete" parameterType="int">
  delete from user where id=#{id}
  </delete>
  <!-- 根据id修改学生信息 -->
  <update id="update" parameterType="user">
  update user set name=#{name},age=#{age} where id=#{id}
  </update>
  <!-- 根据id查询 -->
  <select id="getById" parameterType="int" resultType="user">
  select * from user where id=#{id}
  </select>
  <!-- 查询所有 -->
  <select id="list" parameterType="int" resultType="user">
  select * from user
  </select>
</mapper>
UserMapper.xml

package com.beilin.controller;
import com.beilin.entity.User;
import com.beilin.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.List;
@RestController
public class UserController {
  @Autowired
  private UserMapper userMapper;
    //插入user
  @RequestMapping("/user")
  public void insert( User user) {
    userMapper.insert(user);
  }
   //根据id删除
  @RequestMapping("/user1/{id}")
  public void delete(@PathVariable("id") Integer id) {
    userMapper.delete(id);
  }
    //修改
  @RequestMapping("/user2/{id}")
  public void update(User user,@PathVariable("id") Integer id) {
    userMapper.update(user);
  }
   //根据id查询学生
  @RequestMapping("/user3/{id}")
  public User getById(@PathVariable("id") Integer id) {
    User user = userMapper.getById(id);
    return user;
  }
  //查询全部
  @RequestMapping("/users")
  public List<User> list(){
    List<User> users = userMapper.list();
    return users;
  }
}
UserController.java

<resources>
      <resource>
        <directory>src/main/java</directory>
        <includes>
          <include>**/*.xml</include>
        </includes>
        <filtering>true</filtering>
      </resource>
 </resources>
resources