okhttp3使用

以下是我对okhttp使用的一些总结:

同步Get请求

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

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());      }    });}

提取响应头

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方式提交String

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 {    //这种方式避免提交过长的字符串    String postBody = ""        + "Releases\n"        + "--------\n"        + "\n"        + " * _1.0_ May 6, 2013\n"        + " * _1.1_ June 15, 2013\n"        + " * _1.2_ August 11, 2013\n";    Request request = new Request.Builder()        .url("https://api.github.com/markdown/raw")        .post(RequestBody.create(MEDIA_TYPE_MARKDOWN, postBody))        .build();    Response response = client.newCall(request).execute();    if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);    System.out.println(response.body().string());}

Post方式提交流

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 {    //这里重写了requestBody 的俩个方法,指定了它上传的类型,并且使用okio的BufferedSink 进行数据的提交    RequestBody requestBody = new RequestBody() {      @Override       public MediaType contentType() {        return MEDIA_TYPE_MARKDOWN;      }      @Override       public void writeTo(BufferedSink sink) throws IOException {        sink.writeUtf8("Numbers\n");        sink.writeUtf8("-------\n");        for (int i = 2; i <= 997; i++) {          sink.writeUtf8(String.format(" * %s = %s\n", 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());}

Post方式提交文件

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());}

Post方式提交表单

private final OkHttpClient client = new OkHttpClient();public void run() throws Exception {    //使用FormEncodingBuilder来构建和HTML<form>标签相同效果的请求体。    //键值对将使用一种HTML兼容形式的URL编码来进行编码。    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());}

Post方式提交分块请求

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 {    //MultipartBuilder可以构建复杂的请求体，与HTML文件上传形式兼容。    //多块请求体中每块请求都是一个请求体，可以定义自己的请求头。    //这些请求头可以用来描述这块请求，例如他的Content-Disposition。    //如果Content-Length和Content-Type可用的话，他们会被自动添加到请求头中。    RequestBody requestBody = new MultipartBuilder()        .type(MultipartBuilder.FORM)        .addPart(            Headers.of("Content-Disposition", "form-data; name=\"title\""),            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());}

异步上传Multipart文件

private static final MediaType MEDIA_TYPE_PNG = MediaType.parse("image/png");private void sendMultipart(){    mOkHttpClient = new OkHttpClient();    RequestBody requestBody = new MultipartBody.Builder()            .setType(MultipartBody.FORM)            .addFormDataPart("title", "wangshu")            .addFormDataPart("image", "wangshu.jpg",                    RequestBody.create(MEDIA_TYPE_PNG, new File("/sdcard/wangshu.jpg")))            .build();    Request request = new Request.Builder()            .header("Authorization", "Client-ID " + "...")            .url("https://api.imgur.com/3/image")            .post(requestBody)            .build();   mOkHttpClient.newCall(request).enqueue(new Callback() {       @Override       public void onFailure(Call call, IOException e) {       }       @Override       public void onResponse(Call call, Response response) throws IOException {           Log.i("wangshu", response.body().string());       }   });}

使用Gson来解析JSON响应

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);    //ResponseBody.charStream()使用响应头Content-Type指定的字符集来解析响应体。默认是UTF-8。    Gist gist = gson.fromJson(response.body().charStream(), Gist.class);    for (Map.Entry<String, GistFile> entry : gist.files.entrySet()) {      System.out.println(entry.getKey());      System.out.println(entry.getValue().content);    }}static class Gist {    Map<String, GistFile> files;}static class GistFile {    String content;}

响应缓存: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());    Response response2 = client.newCall(request).execute();    if (!response2.isSuccessful()) throw new IOException("Unexpected code " + response2);    String response2Body = response2.body().string();    System.out.println("Response 2 response:          " + response2);    System.out.println("Response 2 cache response:    " + response2.cacheResponse());    System.out.println("Response 2 network response:  " + response2.networkResponse());    System.out.println("Response 2 equals Response 1? " + response1Body.equals(response2Body));}

缓存

//创建Cache File httpCacheDirectory = new File(MyApp.getContext().getCacheDir(), "OkHttpCache"); Cache cache = new Cache(httpCacheDirectory, 10 * 1024 * 1024); httpClientBuilder.cache(cache); //设置缓存 httpClientBuilder.addNetworkInterceptor(getCacheInterceptor2()); httpClientBuilder.addInterceptor(getCacheInterceptor2());

缓存拦截器

缓存时间自己根据情况设定

/**     * 在无网络的情况下读取缓存，有网络的情况下根据缓存的过期时间重新请求,     *     * @return     */    public Interceptor getCacheInterceptor2() {        Interceptor commonParams = new Interceptor() {            @Override            public okhttp3.Response intercept(Chain chain) throws IOException {                Request request = chain.request();                if (!NetworkUtils.isConnected()) {                    //无网络下强制使用缓存，无论缓存是否过期,此时该请求实际上不会被发送出去。                    request = request.newBuilder().cacheControl(CacheControl.FORCE_CACHE).build();                }                okhttp3.Response response = chain.proceed(request);                if (NetworkUtils.isConnected()) {                    //有网络情况下，根据请求接口的设置，配置缓存。                    // 这样在下次请求时，根据缓存决定是否真正发出请求。                    String cacheControl = request.cacheControl().toString();                    //当然如果你想在有网络的情况下都直接走网络，那么只需要                    // 将其超时时间这是为0即可:String cacheControl="Cache-Control:public,max-age=0"                    int maxAge = 60 * 60;                    // read from cache for 1 minute                    return response.newBuilder()                            .header("Cache-Control", cacheControl).header("Cache-Control", "public, max-age=" + maxAge).removeHeader("Pragma").build();                } else {                    //无网络                     int maxStale = 60 * 60 * 24 * 28;                    // tolerate 4-weeks stale                     return response.newBuilder()                    //.header("Cache-Control", "public,only-if-cached,max-stale=360000")                    .header("Cache-Control", "public,only-if-cached,max-stale=" + maxStale).removeHeader("Pragma").build();                }            }        }; return commonParams;    }}

取消一个Call

使用Call.cancel()可以立即停止掉一个正在执行的call。如果一个线程正在写请求或者读响应，将会引发IOException。当call没有必要的时候，使用这个api可以节约网络资源。例如当用户离开一个应用时。不管同步还是异步的call都可以取消。
你可以通过tags来同时取消多个请求。当你构建一请求时，使用RequestBuilder.tag(tag)来分配一个标签。之后你就可以用OkHttpClient.cancel(tag)来取消所有带有这个tag的call。

每个call的配置

使用OkHttpClient，所有的HTTP Client配置包括代理设置、超时设置、缓存设置。当你需要为单个call改变配置的时候，clone 一个 OkHttpClient。这个api将会返回一个浅拷贝（shallow copy），你可以用来单独自定义。下面的例子中，我们让一个请求是500ms的超时、另一个是3000ms的超时。

private final OkHttpClient client = new OkHttpClient();public void run() throws Exception {    Request request = new Request.Builder()        .url("http://httpbin.org/delay/1") // This URL is served with a 1 second delay.        .build();    try {      Response response = client.clone() // Clone to make a customized OkHttp for this request.          .setReadTimeout(500, TimeUnit.MILLISECONDS)          .newCall(request)          .execute();      System.out.println("Response 1 succeeded: " + response);    } catch (IOException e) {      System.out.println("Response 1 failed: " + e);    }    try {      Response response = client.clone() // Clone to make a customized OkHttp for this request.          .setReadTimeout(3000, TimeUnit.MILLISECONDS)          .newCall(request)          .execute();      System.out.println("Response 2 succeeded: " + response);    } catch (IOException e) {      System.out.println("Response 2 failed: " + e);    }}

拦截器
1)请求头拦截器

/**     * 拦截器Interceptors     * 使用addHeader()不会覆盖之前设置的header,若使用header()则会覆盖之前的header     *     * @return     */    public static Interceptor getRequestHeader() {        Interceptor headerInterceptor = new Interceptor() {            @Override            public okhttp3.Response intercept(Chain chain) throws IOException {                Request originalRequest = chain.request();                Request.Builder builder = originalRequest.newBuilder();                builder.addHeader("version", "1");                builder.addHeader("time", System.currentTimeMillis() + "");                Request.Builder requestBuilder =builder.method(originalRequest.method(), originalRequest.body());                Request request = requestBuilder.build();                return chain.proceed(request);            }        };        return headerInterceptor;    }

2)统一请求拦截器

/** * 拦截器Interceptors * 统一的请求参数 */private Interceptor commonParamsInterceptor() {        Interceptor commonParams = new Interceptor() {            @Override            public okhttp3.Response intercept(Chain chain) throws IOException {                Request originRequest = chain.request();                Request request;                HttpUrl =httpUrl=originRequest.url().newBuilder().addQueryParameter("paltform", "android").addQueryParameter("version", "1.0.0").build();                request = originRequest.newBuilder().url(httpUrl).build();                return chain.proceed(request);            }        };        return commonParams;    }   

3)时间拦截器

/**     * 拦截器Interceptors     * 通过响应拦截器实现了从响应中获取服务器返回的time     *     * @return     */    public static Interceptor getResponseHeader() {        Interceptor interceptor = new Interceptor() {            @Override            public okhttp3.Response intercept(Chain chain) throws IOException {                okhttp3.Response response = chain.proceed(chain.request());                String timestamp = response.header("time");                if (timestamp != null) {                    //获取到响应header中的time                }                return response;            }        };        return interceptor;    }