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Spring Boot与Kotlin使用Spring Data Rest创建HAL风格Restful接口

REST web服务已成为在web上应用程序集成的首选方式。在其核心中，REST定义了系统由客户端交互的资源组成。这些资源以超媒体驱动的方式实现。Spring MVC为构建这些服务提供了坚实的基础。但是，对于多域对象系统，即使实施REST web服务的最简单原则也可能相当乏味，并且导致大量样板代码。

Spring Data REST构建在Spring Data repositories之上，并自动将其导出为REST资源。它利用超媒体来允许客户端查找存储库暴露的功能，并将这些资源自动集成到相关的超媒体功能中。

根据model，生成HAL风格的restful API
根据model，维护实体之间的关系
支持分页
允许动态地过滤集合资源
允许通过处理Spring ApplicationEvents处理REST请求。
目前支持JPA，MongoDB，Neo4j，Solr，Cassandra，Gemfire。
支持自定义

将Spring Data REST添加到Spring Boot项目

dependencies {
 ...
 compile "org.springframework.boot:spring-boot-starter-data-rest:$spring_boot_version"
 ...
}

完整的 build.gradle 文件

group 'name.quanke.kotlin'
version '1.0-SNAPSHOT'

buildscript {
 ext.kotlin_version = '1.2.10'
 ext.spring_boot_version = '1.5.4.RELEASE'
 ext.springfox_swagger2_version = '2.7.0'
 ext.mysql_version = '5.1.21'
 ext.mybatis_version = '1.1.1'
 repositories {
 mavenCentral()
 }
 dependencies {
 classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 classpath("org.springframework.boot:spring-boot-gradle-plugin:$spring_boot_version")

// Kotlin整合SpringBoot的默认无参构造函数，默认把所有的类设置open类插件
 classpath("org.jetbrains.kotlin:kotlin-noarg:$kotlin_version")
 classpath("org.jetbrains.kotlin:kotlin-allopen:$kotlin_version")
 }
}

apply plugin: 'kotlin'
apply plugin: "kotlin-spring" // See https://kotlinlang.org/docs/reference/compiler-plugins.html#kotlin-spring-compiler-plugin
apply plugin: 'org.springframework.boot'
apply plugin: "kotlin-jpa" //https://stackoverflow.com/questions/32038177/kotlin-with-jpa-default-constructor-hell
jar {
 baseName = 'chapter11-6-7-service'
 version = '0.1.0'
}
repositories {
 mavenCentral()
}


dependencies {
 compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:$kotlin_version"
 compile("org.jetbrains.kotlin:kotlin-reflect:${kotlin_version}")

 compile "org.springframework.boot:spring-boot-starter-data-jpa:$spring_boot_version"
 compile "org.springframework.boot:spring-boot-starter-data-rest:$spring_boot_version"
 compile "mysql:mysql-connector-java:$mysql_version"


 testCompile "org.springframework.boot:spring-boot-starter-test:$spring_boot_version"
 testCompile "org.jetbrains.kotlin:kotlin-test-junit:$kotlin_version"

}

compileKotlin {
 kotlinOptions.jvmTarget = "1.8"
}
compileTestKotlin {
 kotlinOptions.jvmTarget = "1.8"
}

创建对象User

import javax.persistence.*

/**
 * Created by http://quanke.name on 2018/1/10.
 */

@Entity
data class User(
 @Id
 @GeneratedValue(strategy = GenerationType.AUTO)
 var id: Long = -1,
 @Column(nullable = false)
 var username: String = "",

 var password: String = ""


)

创建UserRepository

增加 @RepositoryRestResource 注解关于 @RepositoryRestResource 详细的使用介绍，请参考： https://springcloud.cc/spring-data-rest-zhcn.html

import name.quanke.kotlin.chaper11_6_7.entity.User
import org.springframework.data.jpa.repository.JpaRepository
import org.springframework.data.jpa.repository.Query
import org.springframework.data.repository.query.Param
import org.springframework.data.rest.core.annotation.RepositoryRestResource

@RepositoryRestResource(path="user")
interface UserRepository : JpaRepository<User, Long> {

 fun findByUsername(username: String): List<User>

 fun findByUsernameAndPassword(username: String, password: String?): User

 @Query("from User u where u.username=:username")
 fun findUser(@Param("username") username: String): User

}

配置

在 application.yml 文件中增加

spring:
 datasource:
 url: jdbc:mysql://localhost:3306/test
 username: root
 password: 123456
 driver-class-name: com.mysql.jdbc.Driver

启动

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


/**
 * Created by http://quanke.name on 2018/1/9.
 */

//参考：http://blog.csdn.net/soul_code/article/details/54108105

@SpringBootApplication
class Application

fun main(args: Array<String>) {
 SpringApplication.run(Application::class.java, *args)
}

测试

访问 127.0.0.1:8080/user

{
 "_embedded": {
 "users": [
 {
 "username": "http://gof.quanke.name",
 "password": "1111",
 "_links": {
 "self": {
 "href": "http://127.0.0.1:8083/user/73"
 },
 "user": {
 "href": "http://127.0.0.1:8083/user/73"
 }
 }
 },
 {
 "username": "java.quanke.name",
 "password": "12",
 "_links": {
 "self": {
 "href": "http://127.0.0.1:8083/user/74"
 },
 "user": {
 "href": "http://127.0.0.1:8083/user/74"
 }
 }
 },
 {
 "username": "test.quanke.name",
 "password": "aa",
 "_links": {
 "self": {
 "href": "http://127.0.0.1:8083/user/75"
 },
 "user": {
 "href": "http://127.0.0.1:8083/user/75"
 }
 }
 },
 {
 "username": "es.quanke.name",
 "password": "12",
 "_links": {
 "self": {
 "href": "http://127.0.0.1:8083/user/76"
 },
 "user": {
 "href": "http://127.0.0.1:8083/user/76"
 }
 }
 },
 {
 "username": "as.quanke.name",
 "password": "12",
 "_links": {
 "self": {
 "href": "http://127.0.0.1:8083/user/77"
 },
 "user": {
 "href": "http://127.0.0.1:8083/user/77"
 }
 }
 },
 {
 "username": "vertx.quanke.name",
 "password": "12",
 "_links": {
 "self": {
 "href": "http://127.0.0.1:8083/user/78"
 },
 "user": {
 "href": "http://127.0.0.1:8083/user/78"
 }
 }
 }
 ]
 },
 "_links": {
 "self": {
 "href": "http://127.0.0.1:8083/user{?page,size,sort}",
 "templated": true
 },
 "profile": {
 "href": "http://127.0.0.1:8083/profile/user"
 },
 "search": {
 "href": "http://127.0.0.1:8083/user/search"
 }
 },
 "page": {
 "size": 20,
 "totalElements": 6,
 "totalPages": 1,
 "number": 0
 }
}

访问 127.0.0.1:8083/user/73

注意： 73 是user id 根据自己的实际情况测试

{
 "username": "http://gof.quanke.name",
 "password": "1111",
 "_links": {
 "self": {
 "href": "http://127.0.0.1:8083/user/73"
 },
 "user": {
 "href": "http://127.0.0.1:8083/user/73"
 }
 }
}

Spring Data REST 能做的事情很多，这篇文章先介绍到这里，先在这里埋个坑，之后会出更加详细的文章说Spring Data REST。

原文 http://quanke.name/posts/42854/

正文到此结束