okhttp-extension 是针对 okhttp 3 增强的网络框架。使用 Kotlin 特性编写,提供便捷的 DSL 方式创建网络请求,支持协程、响应式编程等等。
其 core 模块只依赖 OkHttp,不会引入第三方库。
okhttp-extension 可以整合 Retrofit、Feign 框架,还提供了很多常用的拦截器。 另外,okhttp-extension 也给开发者提供一种新的选择。
github地址:https://github.com/fengzhizi715/okhttp-extension
Features:
- 支持 DSL 创建 HTTP
GET
/POST
/PUT
/HEAD
/DELETE
/PATCH
requests. - 支持 Kotlin 协程
- 支持响应式(RxJava、Spring Reactor)
- 支持函数式
- 支持熔断器(Resilience4j)
- 支持异步请求的取消
- 支持 Request、Response 的拦截器
- 提供常用的拦截器
- 支持自定义线程池
- 支持整合 Retrofit、Feign 框架
- 支持 Websocket 的实现、自动重连等
- core 模块只依赖 OkHttp,不依赖其他第三方库
okhttp-extension.png
一. General
1.1 Basic
无需任何配置(零配置)即可直接使用,仅限于 Get 请求。
"https://baidu.com".httpGet().use { println(it) }
或者需要依赖协程,也仅限于 Get 请求。
"https://baidu.com".asyncGet() .await() .use { println(it) }
1.2 Config
配置 OkHttp 相关的参数以及拦截器,例如:
const val DEFAULT_CONN_TIMEOUT = 30 val loggingInterceptor by lazy { LogManager.logProxy(object : LogProxy { // 必须要实现 LogProxy ,否则无法打印网络请求的 request 、response override fun e(tag: String, msg: String) { } override fun w(tag: String, msg: String) { } override fun i(tag: String, msg: String) { println("$tag:$msg") } override fun d(tag: String, msg: String) { println("$tag:$msg") } }) LoggingInterceptor.Builder() .loggable(true) // TODO: 发布到生产环境需要改成false .request() .requestTag("Request") .response() .responseTag("Response") // .hideVerticalLine()// 隐藏竖线边框 .build() } val httpClient: HttpClient by lazy { HttpClientBuilder() .baseUrl("http://localhost:8080") .allTimeouts(DEFAULT_CONN_TIMEOUT.toLong(), TimeUnit.SECONDS) .addInterceptor(loggingInterceptor) .addInterceptor(CurlLoggingInterceptor()) .serializer(GsonSerializer()) .jsonConverter(GlobalRequestJSONConverter::class) .build() }
配置完之后,就可以直接使用 httpClient
httpClient.get{ url { url = "/response-headers-queries" "param1" to "value1" "param2" to "value2" } header { "key1" to "value1" "key2" to "value2" } }.use { println(it) }
这里的 url 需要和 baseUrl 组成完整的 url。比如:http://localhost:8080/response-headers-queries
当然,也可以使用 customUrl 替代 baseUrl + url 作为完整的 url
1.3 AOP
针对所有 request、response 做一些类似 AOP 的行为。
需要在构造 httpClient 时,调用 addRequestProcessor()、addResponseProcessor() 方法,例如:
val httpClientWithAOP by lazy { HttpClientBuilder() .baseUrl("http://localhost:8080") .allTimeouts(DEFAULT_CONN_TIMEOUT.toLong(), TimeUnit.SECONDS) .addInterceptor(loggingInterceptor) .serializer(GsonSerializer()) .jsonConverter(GlobalRequestJSONConverter::class) .addRequestProcessor { _, builder -> println("request start") builder } .addResponseProcessor { println("response start") } .build() }
这样在进行 request、response 时,会分别打印"request start"和"response start"。
因为在创建 request 之前,会处理所有的 RequestProcessor;在响应 response 之前,也会用内部的 ResponseProcessingInterceptor 拦截器来处理 ResponseProcessor。
RequestProcessor、ResponseProcessor 分别可以认为是 request、response 的拦截器。
// a request interceptor typealias RequestProcessor = (HttpClient, Request.Builder) -> Request.Builder // a response interceptor typealias ResponseProcessor = (Response) -> Unit
我们可以多次调用 addRequestProcessor() 、addResponseProcessor() 方法。
二. DSL
DSL 是okhttp-extension
框架的特色。包含使用 DSL 创建各种 HTTP Request 和使用 DSL 结合声明式编程。
2.1 HTTP Request
使用 DSL 支持创建GET
/POST
/PUT
/HEAD
/DELETE
/PATCH
2.1.1 get
最基本的 get 用法
httpClient.get{ url { url = "/response-headers-queries" "param1" to "value1" "param2" to "value2" } header { "key1" to "value1" "key2" to "value2" } }.use { println(it) }
这里的 url 需要和 baseUrl 组成完整的 url。比如:http://localhost:8080/response-headers-queries
当然,也可以使用 customUrl 替代 baseUrl + url 作为完整的 url
2.1.2 post
基本的 post 请求如下:
httpClient.post{ url { url = "/response-body" } header { "key1" to "value1" "key2" to "value2" } body { form { "form1" to "value1" "form2" to "value2" } } }.use { println(it) }
支持 request body 为 json 字符串
httpClient.post{ url { url = "/response-body" } body("application/json") { json { "key1" to "value1" "key2" to "value2" "key3" to "value3" } } }.use { println(it) }
支持单个/多个文件的上传
val file = File("/Users/tony/Downloads/xxx.png") httpClient.post{ url { url = "/upload" } multipartBody { +part("file", file.name) { file(file) } } }.use { println(it) }
更多 post 相关的方法,欢迎使用者自行探索。
2.1.3 put
httpClient.put{ url { url = "/response-body" } header { "key1" to "value1" "key2" to "value2" } body("application/json") { string("content") } }.use { println(it) }
2.1.4 delete
httpClient.delete{ url { url = "/users/tony" } }.use { println(it) }
2.1.5 head
httpClient.head{ url { url = "/response-headers" } header { "key1" to "value1" "key2" to "value2" "key3" to "value3" } }.use { println(it) }
2.1.6 patch
httpClient.patch{ url { url = "/response-body" } header { "key1" to "value1" "key2" to "value2" } body("application/json") { string("content") } }.use { println(it) }
2.2 Declarative
像使用 Retrofit、Feign 一样,在配置完 httpClient 之后,需要定义一个 ApiService 它用于声明所调用的全部接口。ApiService 所包含的方法也是基于 DSL 的。例如:
class ApiService(client: HttpClient) : AbstractHttpService(client) { fun testGet(name: String) = get<Response> { url = "/sayHi/$name" } fun testGetWithPath(path: Map<String, String>) = get<Response> { url = "/sayHi/{name}" pathParams = Params.from(path) } fun testGetWithHeader(headers: Map<String, String>) = get<Response> { url = "/response-headers" headersParams = Params.from(headers) } fun testGetWithHeaderAndQuery(headers: Map<String, String>, queries: Map<String,String>) = get<Response> { url = "/response-headers-queries" headersParams = Params.from(headers) queriesParams = Params.from(queries) } fun testPost(body: Params) = post<Response> { url = "/response-body" bodyParams = body } fun testPostWithModel(model: RequestModel) = post<Response>{ url = "/response-body" bodyModel = model } fun testPostWithJsonModel(model: RequestModel) = jsonPost<Response>{ url = "/response-body-with-model" jsonModel = model } fun testPostWithResponseMapper(model: RequestModel) = jsonPost<ResponseData>{ url = "/response-body-with-model" jsonModel = model responseMapper = ResponseDataMapper::class } }
定义好 ApiService 就可以直接使用了,例如:
val apiService by lazy { ApiService(httpClient) } val requestModel = RequestModel() apiService.testPostWithModel(requestModel).sync()
当然也支持异步,会返回CompletableFuture
对象,例如:
val apiService by lazy { ApiService(httpClient) } val requestModel = RequestModel() apiService.testPostWithModel(requestModel).async()
借助于 Kotlin 扩展函数
的特性,也支持返回 RxJava 的 Observable 对象等、Reactor 的 Flux/Mono 对象、Kotlin Coroutines 的 Flow 对象等等。
三. Interceptors
okhttp-extension
框架带有很多常用的拦截器
3.1 CurlLoggingInterceptor
将网络请求转换成 curl 命令的拦截器,便于后端同学调试排查问题。
以下面的代码为例:
httpClient.get{ url { url = "/response-headers-queries" "param1" to "value1" "param2" to "value2" } header { "key1" to "value1" "key2" to "value2" } }.use { println(it) }
添加了 CurlLoggingInterceptor 之后,打印结果如下:
curl: ╔══════════════════════════════════════════════════════════════════════════════════════════════════ ║ curl -X GET -H "key1: value1" -H "key2: value2" "http://localhost:8080/response-headers-queries?param1=value1¶m2=value2" ╚══════════════════════════════════════════════════════════════════════════════════════════════════
CurlLoggingInterceptor 默认使用 println 函数打印,可以使用相应的日志框架进行替换。
3.2 SigningInterceptor
请求签名的拦截器,支持对 query 参数进行签名。
const val TIME_STAMP = "timestamp" const val NONCE = "nonce" const val SIGN = "sign" private val extraMap:MutableMap<String,String> = mutableMapOf<String,String>().apply { this[TIME_STAMP] = System.currentTimeMillis().toString() this[NONCE] = UUID.randomUUID().toString() } private val signingInterceptor = SigningInterceptor(SIGN, extraMap, signer = { val paramMap = TreeMap<String, String>() val url = this.url for (name in url.queryParameterNames) { val value = url.queryParameterValues(name)[0]?:"" paramMap[name] = value } //增加公共参数 paramMap[TIME_STAMP] = extraMap[TIME_STAMP].toString() paramMap[NONCE] = extraMap[NONCE].toString() //所有参数自然排序后拼接 var paramsStr = join("",paramMap.entries .filter { it.key!= SIGN } .map { entry -> String.format("%s", entry.value) }) //生成签名 sha256HMAC(updateAppSecret,paramsStr) })
3.3 TraceIdInterceptor
需要实现TraceIdProvider
接口
interface TraceIdProvider { fun getTraceId():String }
TraceIdInterceptor 会将 traceId 放入 http header 中。
3.4 OAuth2Interceptor
需要实现OAuth2Provider
接口
interface OAuth2Provider { fun getOauthToken():String /** * 刷新token * @return String? */ fun refreshToken(): String? }
OAuth2Interceptor 会将 token 放入 http header 中,如果 token 过期,会调用 refreshToken() 方法进行刷新 token。
3.5 JWTInterceptor
需要实现JWTProvider
接口
interface JWTProvider { fun getJWTToken():String /** * 刷新token * @return String? */ fun refreshToken(): String? }
、
JWTInterceptor 会将 token 放入 http header 中,如果 token 过期,会调用 refreshToken() 方法进行刷新 token。
3.6 LoggingInterceptor
可以使用我开发的okhttp-logging-interceptor将 http request、response 的数据格式化的输出。
四. Coroutines
Coroutines 是 Kotlin 的特性,我们使用okhttp-extension
也可以很好地利用 Coroutines。
4.1 Coroutines
例如,最基本的使用
"https://baidu.com".asyncGet() .await() .use { println(it) }
亦或者
httpClient.asyncGet{ url{ url = "/response-headers-queries" "param1" to "value1" "param2" to "value2" } header { "key1" to "value1" "key2" to "value2" } }.await().use { println(it) }
以及
httpClient.asyncPost{ url { url = "/response-body" } header { "key1" to "value1" "key2" to "value2" } body("application/json") { json { "key1" to "value1" "key2" to "value2" "key3" to "value3" } } }.await().use{ println(it) }
asyncGet\asyncPost\asyncPut\asyncDelete\asyncHead\asyncPatch 函数在coroutines
模块中,都是 HttpClient 的扩展函数,会返回Deferred<Response>
对象。
同样,他们也是基于 DSL 的。
4.2 Flow
coroutines
模块也提供了 flowGet\flowPost\flowPut\flowDelete\flowHead\flowPatch 函数,也是 HttpClient 的扩展函数,会返回Flow<Response>
对象。
例如:
httpClient.flowGet{ url{ url = "/response-headers-queries" "param1" to "value1" "param2" to "value2" } header { "key1" to "value1" "key2" to "value2" } }.collect { println(it) }
或者
httpClient.flowPost{ url { url = "/response-body" } header { "key1" to "value1" "key2" to "value2" } body("application/json") { json { "key1" to "value1" "key2" to "value2" "key3" to "value3" } } }.collect{ println(it) }
五. WebSocket
OkHttp 本身支持 WebSocket ,因此okhttp-extension
对 WebSocket 做了一些增强,包括重连、连接状态的监听等。
5.1 Reconnect
在实际的应用场景中,WebSocket 的断线是经常发生的。例如:网络发生切换、服务器负载过高无法响应等都可能是 WebSocket 的断线的原因。
客户端一旦感知到长连接不可用,就应该发起重连。okhttp-extension
的 ReconnectWebSocketWrapper 类是基于 OkHttp 的 WebSocket 实现的包装类,具有自动重新连接的功能。
在使用该包装类时,可以传入自己实现的 WebSocketListener 来监听 WebSocket 各个状态以及对消息的接收,该类也支持对 WebSocket 连接状态变化的监听、支持设置重连的次数和间隔。
例如:
// 支持重试的 WebSocket 客户端 ws = httpClient.websocket("http://127.0.0.1:9876/ws",listener = object : WebSocketListener() { override fun onOpen(webSocket: WebSocket, response: Response) { logger.info("connection opened...") websocket = webSocket disposable = Observable.interval(0, 15000,TimeUnit.MILLISECONDS) // 每隔 15 秒发一次业务上的心跳 .subscribe({ heartbeat() }, { }) } override fun onMessage(webSocket: WebSocket, text: String) { logger.info("received instruction: $text") } override fun onMessage(webSocket: WebSocket, bytes: ByteString) { } override fun onClosing(webSocket: WebSocket, code: Int, reason: String) { logger.info("connection closing: $code, $reason") websocket = null disposable?.takeIf { !it.isDisposed }?.let { it.dispose() } } override fun onClosed(webSocket: WebSocket, code: Int, reason: String) { logger.error("connection closed: $code, $reason") websocket = null disposable?.takeIf { !it.isDisposed }?.let { it.dispose() } } override fun onFailure(webSocket: WebSocket, t: Throwable, response: Response?) { logger.error("websocket connection error") websocket = null disposable?.takeIf { !it.isDisposed }?.let { it.dispose() } } },wsConfig = WSConfig())
5.2 onConnectStatusChangeListener
ReconnectWebSocketWrapper 支持对 WebSocket 连接状态的监听,只要实现onConnectStatusChangeListener
即可。
ws?.onConnectStatusChangeListener = { logger.info("${it.name}") status = it }