spring boot快速入门 4: jpa数据库操作实现增删改查

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spring boot jpa逆向生成表简单实例：

第一步：pom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.payease</groupId>
<artifactId>girl</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging> <name>girl</name>
<description>Demo project for Spring Boot</description> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.8.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-test</artifactId>
<scope>test</scope>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency> 
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency> 
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>javax.persistence</groupId>
<artifactId>persistence-api</artifactId>
<version>1.0</version>
</dependency>
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-configuration-processor</artifactId> <optional>true</optional> </dependency> </dependencies> <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build></project>

第二步：配置文件application.yml。

spring:
profiles:
active: dev
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/dbgirl
username: root
password: 1234
jpa:
hibernate:
ddl-auto: update
show-sql: true

update第一次运行会创建表若原来有表且有数据会保留原来的数据

第三步：配置问件application-dev.yml

server:
port: 8080
girl:
cupSize: B
age: 18

第四步：创建数据库（navigate）

第五步：创建实体类

package com.payease.entity;import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;/**
* Created by liuxiaoming on 2017/11/6.
*/
@Entity
public class Girl {
public int getId() {
return id;
} public void setId(int id) {
this.id = id;
} public String getCupSize() {
return cupSize;
} public void setCupSize(String cupSize) {
this.cupSize = cupSize;
} public int getAge() {
return age;
} public void setAge(int age) {
this.age = age;
} @Id
@GeneratedValue private int id;
private String cupSize;
private int age;}

第六步：创建启动文件并启动项目

package com.payease;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;@SpringBootApplication
//@ComponentScan(basePackages={"com.payease.entity"})
public class GirlApplication { public static void main(String[] args) {
SpringApplication.run(GirlApplication.class, args);
}
}

根据所创建的表实现简单的增删改查功能：

实现第一个接口：

第一步：编写service

package com.payease.service;import com.payease.entity.Girl;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;/**
* Created by liuxiaoming on 2017/11/6.
*/
@Repository
public interface GirlService extends JpaRepository<Girl,Integer>{
}

第二步：编写controller

package com.payease.controller;import com.payease.entity.Girl;
import com.payease.service.GirlService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;import java.util.List;/**
* Created by liuxiaoming on 2017/11/1.
*/
@RestController
//@RequestMapping("/hello")
public class GirlController { @Autowired
private GirlService girlService; @GetMapping("/girls")
public List<Girl> girls(){
return girlService.findAll();
}
}

第三步：启动项目：

第四步：postman提交

其他接口：

第一步controller：

package com.payease.controller;import com.payease.entity.Girl;
import com.payease.service.GirlService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;import java.util.List;/**
* 查询女生列表
* Created by liuxiaoming on 2017/11/1.
*/
@RestController
//@RequestMapping("/hello")
public class GirlController { @Autowired
private GirlService girlService; @GetMapping("/girls")
public List<Girl> girls(){
return girlService.findAll();
} /**
* 创建一个女生
*/
@PostMapping("/girls")
public Girl girlAdd(@RequestParam("cupSize")String cupSize,
@RequestParam("age")Integer age){
Girl girl = new Girl();
girl.setCupSize(cupSize);
girl.setAge(age);
return girlService.save(girl);
} /**
* 通过ID查询一个女生
*/
@PostMapping("/girls/{id}")
public Girl getgirl(@PathVariable("id")Integer id){
return girlService.findOne(id);
} /**
* 通过ID更新一个女生
*/
@PutMapping("/girls/{id}")
public Girl girlUpdate (@PathVariable("id")Integer id,
@RequestParam("cupSize") String cupSize,
@RequestParam("age") Integer age){
Girl girl = new Girl();
girl.setId(id);
girl.setCupSize(cupSize);
girl.setAge(age);
return girlService.save(girl);
} /**
* 通过ID删除一个女生
*/
@DeleteMapping("/girls/{id}")
public void girlDelete(@PathVariable("id")Integer id){
girlService.delete(id);
} /**
* 通过年龄查询女生列表
*/
@GetMapping("/girls/age/{age}")
public List<Girl> girlListByAge(@PathVariable("age")Integer age){
return girlService.findByAge(age);
}
}

第二步：扩展方法service：

package com.payease.service;import com.payease.entity.Girl;
import org.springframework.data.jpa.repository.JpaRepository;import java.util.List;/**
* Created by liuxiaoming on 2017/11/6.
*/
public interface GirlService extends JpaRepository<Girl,Integer>{ //条件查询：通过年龄来查询
public List<Girl> findByAge(Integer age);
}

第三步：项目启动 postman提交：

数据库的sql文件：

/*
Navicat Premium Data Transfer Source Server : localhost
Source Server Type : MySQL
Source Server Version : 50718
Source Host : localhost
Source Database : dbgirl Target Server Type : MySQL
Target Server Version : 50718
File Encoding : utf-8 Date: 11/07/2017 09:45:34 AM
*/SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;-- ----------------------------
-- Table structure for `girl`
-- ----------------------------
DROP TABLE IF EXISTS `girl`;
CREATE TABLE `girl` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`age` int(11) NOT NULL,
`cup_size` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;-- ----------------------------
-- Records of `girl`
-- ----------------------------
BEGIN;
INSERT INTO `girl` VALUES ('1', '18', 'B'), ('2', '20', 'D'), ('3', '20', 'F');
COMMIT;SET FOREIGN_KEY_CHECKS = 1;