简介
本文介绍了 Spring boot 项目如何访问 Mysql 数据库，插入和查询 Mysql 数据。
环境准备
- JDK 1.8 +
- Gradle 4 + or Maven 3.2+
- IDEA
- Postman
- Mysql server 8.0.28
创建 Spring boot 项目
需要这些依赖
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</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>
社区版的 IDEA 可以参考 《社区版 IntelliJ IDEA 如何创建Spring boot项目》
旗舰版的 IDEA 安装 spring initializr 后创建 Spring boot
配置文件
src/main/resources/application.properties
spring.jpa.hibernate.ddl-auto=update
spring.datasource.url=jdbc:mysql://172.23.176.3:3306/test
spring.datasource.username=test
spring.datasource.password=test
spring.datasource.driver-class-name =com.mysql.jdbc.Driver
开发过程
1. 创建 Entity 模型
src/main/java/com/example/demo/accessingdatamysql/User.java
package com.example.demo.accessingdatamysql;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity
public class User {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
private String name;
private String email;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
2. 创建Repository
src/main/java/com/example/demo/accessingdatamysql/UserRepository.java
package com.example.demo.accessingdatamysql;
import org.springframework.data.repository.CrudRepository;
public interface UserRepository extends CrudRepository<User, Integer> {
}
3. 创建Controller
src/main/java/com/example/demo/accessingdatamysql/MainController.java
package com.example.demo.accessingdatamysql;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
@Controller
@RequestMapping(path="/demo")
public class MainController {
@Autowired
private UserRepository userRepository;
@PostMapping(path="/add")
public @ResponseBody String addNewUser(@RequestParam String name, @RequestParam String email){
User user = new User();
user.setName(name);
user.setEmail(email);
userRepository.save(user);
return "Saved";
}
@GetMapping(path = "/all")
public @ResponseBody Iterable<User> getAllUsers() {
return userRepository.findAll();
}
}
4. 创建 Spring boot 启动类
src/main/java/com/example/demo/accessingdatamysql/AccessingDataMysqlApplication.java
package com.example.demo.accessingdatamysql;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class AccessingDataMysqlApplication {
public static void main(String[] args) {
SpringApplication.run(AccessingDataMysqlApplication.class,args);
}
}