Android 网络框架OKHttp学习
jopen
9年前
OKHTTP
okHttp: OKHttp是Android版Http客户端。非常高效，支持SPDY、连接池、GZIP和 HTTP 缓存。默认情况下，OKHttp会自动处理常见的网络问题，像二次连接、SSL的握手问题。如果你的应用程序中集成了OKHttp，Retrofit默认会使用OKHttp处理其他网络层请求。An HTTP & SPDY client for Android and Java applications 从Android4.4开始HttpURLConnection的底层实现采用的是okHttp.
使用要求:对于Android：2.3以上，对于Java:java7以上 两个模块： okhttp-urlconnection实现.HttpURLConnection API； okhttp-apache实现Apache HttpClient API. 依赖：okio(https://github.com/square/okio): Okio, which OkHttp uses for fast I/O and resizable buffers.
安装：
maven:com.squareup.okhttpokhttp2.3.0Gradle:
compile 'com.squareup.okhttp:okhttp:2.3.0'
GET A URL
同步GET:
private final OkHttpClient client = new OkHttpClient(); public void run() throws Exception { Request request = new Request.Builder() .url(http://publicobject.com/helloworld.txt) .build(); Response response = client.newCall(request).execute(); if (!response.isSuccessful()) throw new IOException(Unexpected code + response); Headers responseHeaders = response.headers(); for (int i = 0; i < responseHeaders.size(); i++) { System.out.println(responseHeaders.name(i) + : + responseHeaders.value(i)); } System.out.println(response.body().string()); } 异步GET:
在一个工作线程中下载文件，当响应可读时回调Callback接口。读取响应时会阻塞当前线程。OkHttp现阶段不提供异步api来接收响应体。 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(Request request, Throwable throwable) { throwable.printStackTrace(); } @Override public void onResponse(Response response) throws IOException { if (!response.isSuccessful()) throw new IOException(Unexpected code + response); Headers responseHeaders = response.headers(); for (int i = 0; i < responseHeaders.size(); i++) { System.out.println(responseHeaders.name(i) + : + responseHeaders.value(i)); } System.out.println(response.body().string()); } }); } 访问Header:
private final OkHttpClient client = new OkHttpClient(); public void run() throws Exception { Request request = new Request.Builder() .url(https://api.github.com/repos/square/okhttp/issues) .header(User-Agent, OkHttp Headers.java) .addHeader(Accept, application/json; q=0.5) .addHeader(Accept, application/vnd.github.v3+json) .build(); Response response = client.newCall(request).execute(); if (!response.isSuccessful()) throw new IOException(Unexpected code + response); System.out.println(Server: + response.header(Server)); System.out.println(Date: + response.header(Date)); System.out.println(Vary: + response.headers(Vary)); } POST TO A SERVER
Posting a String:
public static final MediaType jsonReq = MediaType.parse(application/json; charset=utf-8); OkHttpClient client = new OkHttpClient(); String post(String url, String json) throws IOException { RequestBody body = RequestBody.create(jsonReq, json); Request request = new Request.Builder() .url(url) .post(body) .build(); Response response = client.newCall(request).execute(); return response.body().string(); } Posting Streaming:
public static final MediaType MEDIA_TYPE_MARKDOWN = MediaType.parse(text/x-markdown; charset=utf-8); private final OkHttpClient client = new OkHttpClient(); public void run() throws Exception { RequestBody requestBody = new RequestBody() { @Override public MediaType contentType() { return MEDIA_TYPE_MARKDOWN; } @Override public void writeTo(BufferedSink sink) throws IOException { sink.writeUtf8(Numbers ); sink.writeUtf8(------- ); for (int i = 2; i <= 997; i++) { sink.writeUtf8(String.format( * %s = %s , i, factor(i))); } } private String factor(int n) { for (int i = 2; i < n; i++) { int x = n / i; if (x * i == n) return factor(x) + × + i; } return Integer.toString(n); } }; Request request = new Request.Builder() .url(https://api.github.com/markdown/raw) .post(requestBody) .build(); Response response = client.newCall(request).execute(); if (!response.isSuccessful()) throw new IOException(Unexpected code + response); System.out.println(response.body().string()); } Posting a File:
public static final MediaType MEDIA_TYPE_MARKDOWN = MediaType.parse(text/x-markdown; charset=utf-8); private final OkHttpClient client = new OkHttpClient(); public void run() throws Exception { File file = new File(README.md); Request request = new Request.Builder() .url(https://api.github.com/markdown/raw) .post(RequestBody.create(MEDIA_TYPE_MARKDOWN, file)) .build(); Response response = client.newCall(request).execute(); if (!response.isSuccessful()) throw new IOException(Unexpected code + response); System.out.println(response.body().string()); } Posting from parameters:
private final OkHttpClient client = new OkHttpClient(); public void run() throws Exception { RequestBody formBody = new FormEncodingBuilder() .add(search, Jurassic Park) .build(); Request request = new Request.Builder() .url(https://en.wikipedia.org/w/index.php) .post(formBody) .build(); Response response = client.newCall(request).execute(); if (!response.isSuccessful()) throw new IOException(Unexpected code + response); System.out.println(response.body().string()); } Posting a multipart request:
private static final String IMGUR_CLIENT_ID = ...; private static final MediaType MEDIA_TYPE_PNG = MediaType.parse(image/png); private final OkHttpClient client = new OkHttpClient(); public void run() throws Exception { // Use the imgur image upload API as documented at https://api.imgur.com/endpoints/image RequestBody requestBody = new MultipartBuilder() .type(MultipartBuilder.FORM) .addPart( Headers.of(Content-Disposition, form-data; name= itle), RequestBody.create(null, Square Logo)) .addPart( Headers.of(Content-Disposition, form-data; name=image), RequestBody.create(MEDIA_TYPE_PNG, new File(website/static/logo-square.png))) .build(); Request request = new Request.Builder() .header(Authorization, Client-ID + IMGUR_CLIENT_ID) .url(https://api.imgur.com/3/image) .post(requestBody) .build(); Response response = client.newCall(request).execute(); if (!response.isSuccessful()) throw new IOException(Unexpected code + response); System.out.println(response.body().string()); } Posing Json with Gson
private final OkHttpClient client = new OkHttpClient(); private final Gson gson = new Gson(); public void run() throws Exception { Request request = new Request.Builder() .url(https://api.github.com/gists/c2a7c39532239ff261be) .build(); Response response = client.newCall(request).execute(); if (!response.isSuccessful()) throw new IOException(Unexpected code + response); Gist gist = gson.fromJson(response.body().charStream(), Gist.class); for (Map.Entry entry : gist.files.entrySet()) { System.out.println(entry.getKey()); System.out.println(entry.getValue().content); } } static class Gist { Map files; } static class GistFile { String content; } Response Caching：
为了缓存响应，你需要一个你可以读写的缓存目录，和缓存大小的限制。这个缓存目录应该是私有的，不信任的程序应不能读取缓存内容。一个缓存目录同时拥有多个缓存访问是错误的。大多数程序只需要调用一次 new OkHttp() ，在第一次调用时配置好缓存，然后其他地方只需要调用这个实例就可以了。否则两个缓存示例互相干扰，破坏响应缓存，而且有可能会导致程序崩溃。
响应缓存使用HTTP头作为配置。你可以在请求头中添加 Cache-Control: max-stale=3600 ,OkHttp缓存会支持。你的服务通过响应头确定响应缓存多长时间，例如使用 Cache-Control: max-age=9600 。
private final OkHttpClient client; public CacheResponse(File cacheDirectory) throws Exception { int cacheSize = 10 * 1024 * 1024; // 10 MiB Cache cache = new Cache(cacheDirectory, cacheSize); client = new OkHttpClient(); client.setCache(cache); } public void run() throws Exception { Request request = new Request.Builder() .url(http://publicobject.com/helloworld.txt) .build(); Response response1 = client.newCall(request).execute(); if (!response1.isSuccessful()) throw new IOException(Unexpected code + response1); String response1Body = response1.body().string(); System.out.println(Response 1 response: + response1); System.out.println(Response 1 cache response: + response1.cacheResponse()); System.out.println(Response 1 network response: + response1.networkResponse()); } Canceling a Call
final Call call = client.newCall(request); call.cancel();
Timeouts:
private final OkHttpClient client; public ConfigureTimeouts() throws Exception { client = new OkHttpClient(); client.setConnectTimeout(10, TimeUnit.SECONDS); client.setWriteTimeout(10, TimeUnit.SECONDS); client.setReadTimeout(30, TimeUnit.SECONDS); } Handling Authentication:
private final OkHttpClient client = new OkHttpClient(); public void run() throws Exception { client.setAuthenticator(new Authenticator() { @Override public Request authenticate(Proxy proxy, Response response) { System.out.println(Authenticating for response: + response); System.out.println(Challenges: + response.challenges()); String credential = Credentials.basic(jesse, password1); return response.request().newBuilder() .header(Authorization, credential) .build(); } @Override public Request authenticateProxy(Proxy proxy, Response response) { return null; // Null indicates no attempt to authenticate. } }); Request request = new Request.Builder() .url(http://publicobject.com/secrets/hellosecret.txt) .build(); Response response = client.newCall(request).execute(); if (!response.isSuccessful()) throw new IOException(Unexpected code + response); System.out.println(response.body().string()); }为避免当验证失败时多次重试，我们可以通过返回null来放弃验证： if (responseCount(response) >= 3) { return null; // If we've failed 3 times, give up. } //添加以下方法 private int responseCount(Response response) { int result = 1; while ((response = response.priorResponse()) != null) { result++; } return result; } Interceptors
class LoggingInterceptor implements Interceptor { @Override public Response intercept(Chain chain) throws IOException { Request request = chain.request(); long t1 = System.nanoTime(); logger.info(String.format(Sending request %s on %s%n%s, request.url(), chain.connection(), request.headers())); Response response = chain.proceed(request); long t2 = System.nanoTime(); logger.info(String.format(Received response for %s in %.1fms%n%s, response.request().url(), (t2 - t1) / 1e6d, response.headers())); return response; } }Application Interceptors：
OkHttpClient client = new OkHttpClient(); client.interceptors().add(new LoggingInterceptor());
Network Interceptors
OkHttpClient client = new OkHttpClient(); client.networkInterceptors().add(new LoggingInterceptor());