在SpringBoot中，通过Spring Data JPA 和 Spring Data Rest可以快速构建出一个RESTFul应用。
关于Spring Data JPA：JPA是一种规范，而Spring Data JPA可以有效简化关系型数据库访问代码。
关于Spring Data：Spring Data是Spring的一个子项目，致力于简化数据库访问。
JPA中有种定义，将Java对象【POJO】映射到数据库。
@Entity（name=“t_book”）
表明该类为一个实体类，它默认对应数据库中的表名是t_book，在项目启动时会根据该类自动生成一张表。
【如果不配置name，默认表名为类名】
@Id
表示该属性是一个主键，@GeneratedValue(strategy = GenerationType.IDENTITY)表示主键自动生成，strategy表示主键生成策略。
导入pom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>org.sang</groupId>
<artifactId>jparestful</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>jparestful</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.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-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-rest</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.9</version>
</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>
配置数据库连接
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.username=noneplus
spring.datasource.password=Noneplus564925080!
spring.datasource.url=jdbc:mysql://47.103.6.247:3306/restful-jpa?serverTimezone=UTC
spring.jpa.hibernate.ddl-auto=update
spring.jpa.database=mysql
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL57Dialect
spring.jpa.show-sql=true
##每页默认记录数，缺省值为20
#spring.data.rest.default-page-size=2
##分页查询页码参数名，缺省值为page
#spring.data.rest.page-param-name=page
##分页查询记录数参数名，缺省值为size
#spring.data.rest.limit-param-name=size
##分页查询排序参数名，缺省值为sort
#spring.data.rest.sort-param-name=sort
##base-path表示给所有请求路径都加上前缀
#spring.data.rest.base-path=/api
##添加成功时是否返回添加内容
#spring.data.rest.return-body-on-create=true
##更新成功时是否返回更新内容
#spring.data.rest.return-body-on-update=true创建实体类
@Entity(name = "t_book")
public class Book {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String name;
private String author;
//省略getter/setter
@Override
public String toString() {
return "Book{" +
"id=" + id +
", name='" + name + '\'' +
", author='" + author + '\'' +
'}';
}
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 getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
}
创建BookRepository
public interface BookRepository extends JpaRepository<Book, Integer> {
}
JpaRepository
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package org.springframework.data.jpa.repository;
import java.util.List;
import org.springframework.data.domain.Example;
import org.springframework.data.domain.Sort;
import org.springframework.data.repository.NoRepositoryBean;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.data.repository.query.QueryByExampleExecutor;
@NoRepositoryBean
public interface JpaRepository<T, ID> extends PagingAndSortingRepository<T, ID>, QueryByExampleExecutor<T> {
List<T> findAll();
List<T> findAll(Sort var1);
List<T> findAllById(Iterable<ID> var1);
<S extends T> List<S> saveAll(Iterable<S> var1);
void flush();
<S extends T> S saveAndFlush(S var1);
void deleteInBatch(Iterable<T> var1);
void deleteAllInBatch();
T getOne(ID var1);
<S extends T> List<S> findAll(Example<S> var1);
<S extends T> List<S> findAll(Example<S> var1, Sort var2);
}
【在进行这个节点测试之前，需要把代码的其他部分注释掉，之后会有一些自定义的功能】
在数据库添加几条测试数据
打开Postman，输入http://localhost:8080/books
【默认请求路径都是实体类名小写加s】
按照id查询
/**
* 默认请求路径都是实体类名加s
*
* 自定义请求类名：
* @RepositoryRestResource (path = "bs",collectionResourceRel = "bs",itemResourceRel = "b")
* path属性指用bs替代原先的books，collectionResourceRel表示将返回的json集合中的book集合改为bs，
* itemResourceRel表示将单个book的key改为b
*/
@RepositoryRestResource(path = "bs",collectionResourceRel = "bs",itemResourceRel = "b")
public interface BookRepository extends JpaRepository<Book, Integer> {访问:http://localhost:8080/bs
/**@RestResource注解定义：默认请求路径就是方法名，path可自定义路径
* http://localhost:8080/bs/search/author?author=余华
* http://localhost:8080/bs/search/name?name=白夜行
* @param author
* @return
*/
@RestResource(path = "author",rel = "author")
List<Book> findByAuthorContains(@Param("author") String author);
@RestResource(path = "name",rel = "name")
Book findByNameEquals(@Param("name") String name);
https://github.com/HCJ-shadow/SpringBootPlus
原文：https://www.cnblogs.com/noneplus/p/11571997.html