SpringBoot之(二)：基礎篇—SpringBoot+Mybatis+MySql增刪改查

一、前言

上一篇博文我簡單陳述了SpringBoot，並寫了入門程序，啓動類加載運行，訪問成功。

本文主要是結合SpringBoot+Mybatis+MySql來實現數據庫的CRUD操作。

二、代碼

1、創建SpringBoot項目(或者Maven項目)

2、添加Web、Mysql、Mybatis的依賴

3、pom.xml完整配置代碼

<?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、啓動類

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);
    }
}

到這裏，完整的SpringBoot項目就完成了，接下來，就可以整理MyBatis的東西了。

5、填寫配置文件：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】：此處設置了該項目端口，默認爲8080

6、實體類：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(映射器類)：UserMapper.java

該類主要是用於CRUD操作的，一般有兩種方式實現數據庫的增刪改查。

方式一：註解： @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、控制層：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、測試

這裏測試我用了PostMan（一款Http請求模擬工具來測試API接口）發送get/post請求。