1、SpringBoot整合JPA

目錄

1、創建工程spring-boot-jpa

2、配置pom.xml

3、配置application.yml

4、創建User實體類

5、創建數據庫及數據表

6、編寫一個Dao接口

7、創建UserController

8、測試

---

1、創建工程spring-boot-jpa

2、配置pom.xml

<?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>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.1.6.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.mi</groupId>
	<artifactId>spring-boot-jpa</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>spring-boot-jpa</name>
	<description>spring-boot-jpa project for Spring Boot</description>

	<properties>
		<java.version>1.8</java.version>
	</properties>

	<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-jdbc</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>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

3、配置application.yml

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/jpa?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver
  jpa:
    hibernate:
      #更新或創建表結構
      ddl-auto: update
    #控制檯顯示sql
    show-sql: true
    database-platform: org.hibernate.dialect.MySQLDialect

4、創建User實體類

package com.mi.entity;

import javax.persistence.*;

/**
 * Created by chengwen on 2019/7/3.
 */
//使用JPA註解配置映射關係
@Entity //告訴JPA這是一個實體類（和數據表映射的類）
@Table(name = "t_user") //@Table來指定和哪個數據表對應，如果省略默認就是user
@JsonIgnoreProperties(value = { "hibernateLazyInitializer", "handler" })
public class User {

    @Id //這是一個主鍵
    @GeneratedValue(strategy = GenerationType.IDENTITY)     //自增主鍵
    private Integer id;

    @Column(name ="last_name",length = 50)  //這是和數據表對應的一個列
    private String lastName;

    @Column //省略默認列名就是屬性名
    private String email;


    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

5、創建數據庫及數據表

CREATE  TABLE `jpa`.`t_user` (
  `id` INT NOT NULL AUTO_INCREMENT  ,
  `last_name` VARCHAR(45) NULL ,
  `email` VARCHAR(45) NULL ,
  PRIMARY KEY (`id`) );

6、編寫一個Dao接口

package com.mi.repository;

import com.mi.entity.User;
import org.springframework.data.jpa.repository.JpaRepository;

/**
 * Created by chengwen on 2019/7/3.
 */
//繼承jpa來完成對數據庫的操作
public interface UserRepository extends JpaRepository<User,Integer>{
}

7、創建UserController

package com.mi.controller;

import com.mi.entity.User;
import com.mi.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

/**
 * Created by chengwen on 2019/7/3.
 */
@RestController
public class UserController {

    @Autowired
    UserRepository userRepository;

    @GetMapping("/user/{id}")
    public User getUser(@PathVariable("id") Integer id){
        User user = userRepository.getOne(id);
        return user;
    }

    @GetMapping("user")
    public User insertUser(User user){
        User usr = userRepository.save(user);
        return usr;
    }
}

8、測試

新增

http://localhost:8080/user?lastName=zhangsan&[email protected]

結果

{"id":1,"lastName":"zhangsan","email":"[email protected]"}

查詢

http://localhost:8080/user/1

結果

{"id":1,"lastName":"zhangsan","email":"[email protected]"}