Spring boot 与 MySQL 的使用

建一个user表

SET FOREIGN_KEY_CHECKS=0;DROP TABLE IF EXISTS `user`;CREATE TABLE `user` (  `id` int(10) unsigned zerofill NOT NULL AUTO_INCREMENT COMMENT '主键',  `username` varchar(10) DEFAULT NULL COMMENT '用户名',  `password` varchar(10) DEFAULT NULL COMMENT '密码',  PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;INSERT INTO `user` VALUES ('0000000001', '张三', '123');INSERT INTO `user` VALUES ('0000000002', '李四', '123456');INSERT INTO `user` VALUES ('0000000003', ' 王五', '1234567');

创建一个maven项目：

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>spring-boot-demo</artifactId>    <version>0.0.1-SNAPSHOT</version>    <packaging>jar</packaging>    <name>spring-boot-demo1</name>    <description>Demo project for Spring Boot</description>    <parent>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-starter-parent</artifactId>        <version>1.5.7.RELEASE</version>        <relativePath />    </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.springframework.boot</groupId>            <artifactId>spring-boot-starter</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-test</artifactId>            <scope>test</scope>        </dependency>        <!-- JPA Data (包含 Repositories, Entities, Hibernate) -->        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-data-jpa</artifactId>        </dependency>        <!-- mysql连接驱动 -->        <dependency>            <groupId>mysql</groupId>            <artifactId>mysql-connector-java</artifactId>        </dependency>    </dependencies>    <build>        <plugins>            <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>            </plugin>        </plugins>    </build></project>

在 src/main/resources/ 下创建 application.properties文件（编码改为utf8）

spring.jpa.hibernate.ddl-auto=update#none mysql默认，不改变表结构，其他数据库多数为create-drop#update 加载hibernate时，自动更新数据库结构#create 每次加载hibernate，重新创建数据库表结构，#create-drop 加载hibernate时创建，退出时删除表结构spring.datasource.url=jdbc:mysql://localhost:3306/testspring.datasource.username=rootspring.datasource.password=root

创建实体类 User.java

package com.demo.bean;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;@Entitypublic class User {    @Id    @GeneratedValue(strategy = GenerationType.AUTO)    private Integer id;    private String username;    private String password;    public Integer getId() {        return id;    }    public void setId(Integer id) {        this.id = id;    }    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public String getPassword() {        return password;    }    public void setPassword(String password) {        this.password = password;    }}

创建 repository(类似于dao的东西吧~)

package com.demo.repository;import org.springframework.data.repository.CrudRepository;import com.demo.bean.User;//由Spring自动实现，包含CRUD(Create, Read, Update, Delete)public interface UserRepository extends CrudRepository<User, Long>{}

创建一个Controller，UserController.java

package com.demo.controller;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.ResponseBody;import com.demo.bean.User;import com.demo.repository.UserRepository;@Controller@RequestMapping(path = "/user")public class UserController {    @Autowired // 自动注入    private UserRepository userRepository;    @GetMapping(path = "/add") // 只响应GET请求    public @ResponseBody String addUser(@RequestParam String username, @RequestParam String password) {        // @ResponBody表示返回String类型数据        // @RequestParam表示GET或POST请求的参数        User user = new User();        user.setUsername(username);        user.setPassword(password);        User savedUser = userRepository.save(user);        if (savedUser == null) {            return "error";        } else {            return "add success!";        }    }    @GetMapping(path = "/all")    public @ResponseBody Iterable<User> getAllUsers() {        // 返回Json格式或xml格式        return userRepository.findAll();    }}

创建Application类

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

运行程序 Run As -> Maven build... -> spring-boot:run Run

测试，浏览器输入 http://localhost:8080/user/add?username=admin&password=admin

返回 add success，回来看控制台的sql

浏览器输入 http://localhost:8080/user/getAllUser，获取全部用户，可在控制台查看sql语句

源码