SpringBoot之(二)：基础篇—SpringBoot+Mybatis+MySql增删改查详解程序员

一、前言

上一篇博文我简单陈述了SpringBoot，并写了入门程序，启动类加载运行，访问成功。

本文主要是结合SpringBoot+Mybatis+MySql来实现数据库的CRUD操作。

二、代码

1、创建SpringBoot项目(或者Maven项目)

2、添加Web、Mysql、Mybatis的依赖

3、pom.xml完整配置代码

<?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.google</groupId> 
    <artifactId>springboot_mybatis</artifactId> 
    <version>0.0.1-SNAPSHOT</version> 
    <packaging>jar</packaging> 
 
    <name>springboot_mybatis</name> 
    <description>Demo project for Spring Boot</description> 
 
    <parent> 
        <groupId>org.springframework.boot</groupId> 
        <artifactId>spring-boot-starter-parent</artifactId> 
        <version>2.0.1.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> 
        <dependency> 
            <groupId>org.springframework.boot</groupId> 
            <artifactId>spring-boot-starter-web</artifactId> 
        </dependency> 
        <dependency> 
            <groupId>org.mybatis.spring.boot</groupId> 
            <artifactId>mybatis-spring-boot-starter</artifactId> 
            <version>1.3.2</version> 
        </dependency> 
 
        <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>

4、启动类

package com.google; 
 
import org.springframework.boot.SpringApplication; 
import org.springframework.boot.autoconfigure.SpringBootApplication; 
 
@SpringBootApplication 
public class SpringbootMybatisApplication { 
 
    public static void main(String[] args) { 
        SpringApplication.run(SpringbootMybatisApplication.class, args); 
    } 
}

到这里，完整的SpringBoot项目就完成了，接下来，就可以整理MyBatis的东西了。

5、填写配置文件：application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/test 
spring.datasource.username=root 
spring.datasource.password=root 
spring.datasource.driver-class-name=com.mysql.jdbc.Driver 
server.port=1111【注】：此处设置了该项目端口，默认为8080

6、实体类：User.java

package com.google.entity; 
 
/** 
 * Created by 郭子旭 on 2018/4/12 
 */ 
public class User { 
 
    private int id; 
    private String name; 
    private String address; 
 
    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 getAddress() { 
        return address; 
    } 
 
    public void setAddress(String address) { 
        this.address = address; 
    } 
 
    @Override 
    public String toString() { 
        return "User{" + 
                "id=" + id + 
                ", name='" + name + '/'' + 
                ", address='" + address + '/'' + 
                '}'; 
    } 
}

7、接口(映射器类)：UserMapper.java

该类主要是用于CRUD操作的，一般有两种方式实现数据库的增删改查。

方式一：注解： @Insert @Delete @Update @Select

方式二：xml配置文件

package com.google.dao; 
 
import com.google.entity.User; 
import org.apache.ibatis.annotations.*; 
 
import java.util.List; 
 
/** 
 * Created by 郭子旭 on 2018/4/12 
 */ 
@Mapper 
public interface UserMapper { 
 
    @Select("select * from user where id=#{id}") 
    public User selectUserById(int id); 
 
    @Select("select * from user where name=#{name}") 
    public List<User> selectUserByName(String name); 
 
    @Insert("insert into user(name,address) values(#{name},#{address})") 
    public void addUser(User user); 
 
    @Delete("delete from user where id=#{id}") 
    public void deleteUser(int id); 
 
    @Update("update user set name=#{name},address=#{address}") 
    public void updateUser(User user); 
 
}

8、控制层：UserController.java

package com.google.controller; 
 
import com.google.dao.UserMapper; 
import com.google.entity.User; 
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.RestController; 
 
import java.util.List; 
 
/** 
 * Created by 郭子旭 on 2018/4/12 
 */ 
@RestController 
public class UserController { 
 
    @Autowired 
    private UserMapper userMapper; 
 
    @RequestMapping(value = "/selectUserById",method = RequestMethod.POST) 
    public User selectUserById(String id){ 
        User user = userMapper.selectUserById(Integer.parseInt(id)); 
        return  user; 
    } 
 
    @RequestMapping(value = "/selectUserByName",method = RequestMethod.POST) 
    public List<User> selectUserByName(String name){ 
        return userMapper.selectUserByName(name); 
    } 
 
    @RequestMapping(value = "/addUser",method = RequestMethod.POST) 
    public void addUser(User user){ 
        userMapper.addUser(user); 
    } 
 
    @RequestMapping(value = "/deleteUser",method = RequestMethod.POST) 
    public void deleteUser(String id){ 
        userMapper.deleteUser(Integer.parseInt(id)); 
    } 
 
    @RequestMapping(value = "/updateUser",method = RequestMethod.POST) 
    public void updateUser(User user){ 
        userMapper.updateUser(user); 
    } 
}

9、测试

这里测试我用了PostMan（一款Http请求模拟工具来测试API接口）发送get/post请求。