spring boot集成mybatis-plus——新建工程与查询所有数据

标签：spring boot example plus org import public

第一步引入依赖：

<?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>org.example</groupId>
    <artifactId>springbootmybatisplus</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.5</version>
        <relativePath/>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.1</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>

    </dependencies>

</project>

 

 

 

 

 

 

 

 

 

 

第二步：设置数据库信息：

spring.datasource.username=root

spring.datasource.password=123456

spring.datasource.url=jdbc:mysql://localhost:3306/mysql8?characterEncoding=utf8

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

 

 

 

 

数据库信息

 

 

 

 

 

 

 

 

 

第三步：创建实体类：

package org.example.Entity;

import com.baomidou.mybatisplus.annotation.TableName;

@TableName("users")        //不一致时，需要映射
public class MyUser
{
    private int id;

    private String name;

    private int age;

    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;
    }

    @Override
    public String toString()
    {

        return "MyUser{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

第四步：常见mapper文件：

package org.example.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;
import org.example.Entity.MyUser;

@Mapper
public interface UserMapper extends BaseMapper<MyUser>
{

    //所有的CRUD都已经完成
    //不需要像以前一样配置一大堆文件：pojo-dao（连接mybatis，配置mapper.xml文件）==>service-controller

    
    
}

 

 

 

 

 

 

 

 

 

第五步：创建业务层以及实现接口：

package org.example.service;

import org.example.Entity.MyUser;

import java.util.List;

public interface MyUserService
{

    // 查询所有用户
    List<MyUser> findAll();

    

}

 

 

 

 

 

 

 

package org.example.service.Impl;

import org.example.Entity.MyUser;
import org.example.mapper.UserMapper;
import org.example.service.MyUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;

@Service
public class MyUserServiceImpl implements MyUserService
{

    //继承了BaseMapper所有的方法，可以编写自己的扩展方法
    @Autowired
    private UserMapper userMapper;


    @Override
    public List<MyUser> findAll()
    {

        return userMapper.selectList(null);


    }


}

 

 

 

 

 

 

 

 

 

 

 

 

第六步：控制器接口：

package org.example.controller;

import org.example.Entity.MyUser;
import org.example.service.MyUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.List;

@RestController
public class MyUserController
{

    @Autowired
    private MyUserService myUserService;


    @GetMapping(value = "/1")
    public List<MyUser> home1()
    {
        // 查询所有用户信息
        List<MyUser> users = myUserService.findAll();

        for (MyUser user : users)
        {
            System.out.println(user.getId()+"  "+user.getName()+"  "+user.getAge());
        }

        return users;
    }


}

 

 

 

 

 

 

 

 

 

 

第七步：运行主程序：

package org.example;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("org.example.mapper")
public class HelloWorldApplication
{

    public static void main(String[] args)
    {

        SpringApplication.run(HelloWorldApplication.class, args);

    }
}

 

 

 

 

 

 

 

 

 

 

 

 

 

实现如下：

 

 

 

标签：spring,boot,example,plus,org,import,public
From： https://www.cnblogs.com/xiaobaibailongma/p/17091309.html