SpringBoot使用JPA

一.工程目錄如下

二.在pom.xml檔案中引入相關依賴

<?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.xiao</groupId>
    <artifactId>SpringBoot_03</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.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>
        <!-- web元件-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- JPA元件-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <!-- Mysql驅動-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>

</project>

三.在application.yml檔案中配置連線資料庫資訊及JPA的基本配置

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/demo?characterEncoding=utf-8
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: root
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true
    database-platform: org.hibernate.dialect.MySQL5Dialect
    database: mysql
    generate-ddl: true

四.書寫實體類（注意：註解的包不要引錯了）

package com.xiao.pojo;


import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
/**
 * @Author 笑笑
 * @Date 14:34 2018/05/26
 */
@Entity
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int uid;
    private String username;

    public int getUid() {
        return uid;
    }

    public void setUid(int uid) {
        this.uid = uid;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }
}

五.書寫啟動類

package com.xiao;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * @Author 笑笑
 * @Date 14:43 2018/05/26
 */
@SpringBootApplication
public class ApplicationEntry {

    public static void main(String[] args){
        SpringApplication.run(ApplicationEntry.class,args);
    }

}

六.啟動測試

出現以上資訊，或者對應的資料庫中建立了實體類所對應的表，表示可以初步使用JPA運算元據庫了！