0 概述
okhttp是一个现代的网络请求框架
- Http/2 支持 所有访问同一个主机的Request都共用一个socket
- connection pool 连接池 减少请求延迟
- GZIP 压缩数据，减少传输所用的带宽
- Response Cache 避免重复性的Request
1 使用
Get
OkHttpClient client = new OkHttpClient();String run(String url) throws IOException {Request request = new Request.Builder().url(url).build();try (Response response = client.newCall(request).execute()) {return response.body().string();}
}Post
public static final MediaType JSON= MediaType.get("application/json; charset=utf-8");OkHttpClient client = new OkHttpClient();String post(String url, String json) throws IOException {RequestBody body = RequestBody.create(json, JSON);Request request = new Request.Builder().url(url).post(body).build();try (Response response = client.newCall(request).execute()) {return response.body().string();}
}Async
private final OkHttpClient client = new OkHttpClient();public void run() throws Exception {Request request = new Request.Builder().url("http://publicobject.com/helloworld.txt").build();client.newCall(request).enqueue(new Callback() {@Override public void onFailure(Call call, IOException e) {e.printStackTrace();}@Override public void onResponse(Call call, Response response) throws IOException {try (ResponseBody responseBody = response.body()) {if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);Headers responseHeaders = response.headers();for (int i = 0, size = responseHeaders.size(); i < size; i++) {System.out.println(responseHeaders.name(i) + ": " + responseHeaders.value(i));}System.out.println(responseBody.string());}}});}2 源码
2.0 请求过程
2.1 OkHttpClient
- dispatcher
- interceptors
- networkInterceptors
- connectionPool
- proxy
- newCall()
2.2 Call
- Response execute()
- enqueue(Callback responseCallback)
2.3 Request
- url
- method
- headers
- body
- tag
- cacheControl
2.4 Response
- request
- protocol
- code
- message
- headers
- body
- handshake
2.5 RealInterceptorChain
- interceptors
- transmitter
- index
- request
- call
- exchange
2.6 Interceptor
- Response intercept(Chain chain)
2.7 Cache
- DiskLruCache cache;
2.8 Connection
- Route route();
- Socket socket();
- Handshake handshake();
- Protocol protocol();
- connectSocket
- source
- sink
- connectionPool
3 架构
- 中间层
- OKhttp 通过很多中间拦截器来对 Request Response 进行加工
- 实现了数据的 流式链式处理
- 生产者
- 分发器
- 调度器 通过不同状态的 任务队列 来调度任务
- readyCalls runningCalls
- 消费者
- 缓存
- 拦截器
- 类似责任链的效果，链式处理，链式返回
