SpringBoot之结合Spring Data Jpa使用

1、创建SpringBoot工程，添加相关依赖

<?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>jpa</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>jpa</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </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</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-data-jpa</artifactId>
        </dependency>
        <!-- Mysql依赖 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.51</version>
        </dependency>
    </dependencies>

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

2、添加相关配置相关配置文件

########################################################
###datasource
########################################################
spring:
  datasource:
    url: jdbc:mysql://111.230.180.89:3306/springboot
    username: root
    password: xu0719wd
    driver-class-name: com.mysql.jdbc.Driver
  jpa:
    database: MYSQL
    show-sql: true
#Hibernate ddl auto
    hibernate:
        ddl-auto: update
        naming-strategy: org.hibernate.cfg.ImprovedNamingStrategy
    properties:
        hibernate:
            dialect: org.hibernate.dialect.MySQL5Dialect
server:
  port: 8003
  servlet:
    context-path: /jpa

3、创建实体类

package com.example.entity;

import javax.persistence.*;
import java.util.Date;

/**
 * @author admin
 * @date 2018/10/31
 */
@Entity
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;//指定主键及生成策略
    @Column
    private String name;
    @Column(name = "create_time")
    private Date createTime;

    @Column(name = "department_id")
    private Integer departmentId;

    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 Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    public Integer getDepartmentId() {
        return departmentId;
    }

    public void setDepartmentId(Integer departmentId) {
        this.departmentId = departmentId;
    }
}
4、实现

（1）Repository

package com.example.Repository;

import com.example.entity.User;

import org.springframework.data.repository.CrudRepository;

import org.springframework.stereotype.Repository;

/** * @author admin * @date 2018/10/31 */

@Repository public interface UserRepository extends CrudRepository<User,Integer> { }

（1）PagingAndSorttingRepository

继承了CrudRepository，又新增了方法

Iterable<T> findAll(Sort var1);

Page<T> findAll(Pageable var1);

 （2）JpaRepository提供了更多使用功能，Example对对象进行查询