Android-okhttp的基本用法

官方WIKI地址

常见的运用方式:

1. 一般的get请求
2. 一般的post请求
3. 基于Http的文件上传
4. 文件下载
5. 加载图片
6. 支持请求回调，直接返回对象、对象集合
7. 支持session的保持

添加依赖:

compile 'com.squareup.okhttp:okhttp:2.4.0'

GET 请求:

//创建okHttpClient对象
OkHttpClient mOkHttpClient = new OkHttpClient();
//创建一个Request
final Request request = new Request.Builder()
                .url("https://github.com/hongyangAndroid")
                .build();
//以通过Request.Builder设置更多的参数比如：header、method
//new call
Call call = mOkHttpClient.newCall(request); 
//请求加入调度
call.enqueue(new Callback()
        {
            @Override
            public void onFailure(Request request, IOException e)
            {
            }

            @Override
            public void onResponse(final Response response) throws IOException
            {
                    //String htmlStr =  response.body().string();
            }
        });

POST 请求

Request request = buildMultipartFormRequest(
        url, new File[]{file}, new String[]{fileKey}, null);
FormEncodingBuilder builder = new FormEncodingBuilder();   
builder.add("username","张鸿洋");

Request request = new Request.Builder()
                   .url(url)
                .post(builder.build())
                .build();
 mOkHttpClient.newCall(request).enqueue(new Callback(){});

上传文件

File file = new File(Environment.getExternalStorageDirectory(), "balabala.mp4");

RequestBody fileBody = RequestBody.create(MediaType.parse("application/octet-stream"), file);

RequestBody requestBody = new MultipartBuilder()
     .type(MultipartBuilder.FORM)
     .addPart(Headers.of(
          "Content-Disposition", 
              "form-data; name=\"username\""), 
          RequestBody.create(null, "张鸿洋"))
     .addPart(Headers.of(
         "Content-Disposition", 
         "form-data; name=\"mFile\"; 
         filename=\"wjd.mp4\""), fileBody)
     .build();

Request request = new Request.Builder()
    .url("http://192.168.1.103:8080/okHttpServer/fileUpload")
    .post(requestBody)
    .build();

Call call = mOkHttpClient.newCall(request);
call.enqueue(new Callback()
{
    //...
});

Okhttp的简单封装

public class OkHttpUtil {
    private static final OkHttpClient mOkHttpClient = new OkHttpClient();
    static{
        mOkHttpClient.setConnectTimeout(30, TimeUnit.SECONDS);
    }
    /**
     * 该不会开启异步线程。
     * @param request
     * @return
     * @throws IOException
     */
    public static Response execute(Request request) throws IOException{
        return mOkHttpClient.newCall(request).execute();
    }
    /**
     * 开启异步线程访问网络
     * @param request
     * @param responseCallback
     */
    public static void enqueue(Request request, Callback responseCallback){
        mOkHttpClient.newCall(request).enqueue(responseCallback);
    }
    /**
     * 开启异步线程访问网络, 且不在意返回结果（实现空callback）
     * @param request
     */
    public static void enqueue(Request request){
        mOkHttpClient.newCall(request).enqueue(new Callback() {
            
            @Override
            public void onResponse(Response arg0) throws IOException {
                
            }
            
            @Override
            public void onFailure(Request arg0, IOException arg1) {
                
            }
        });
    }
    public static String getStringFromServer(String url) throws IOException{
        Request request = new Request.Builder().url(url).build();
        Response response = execute(request);
        if (response.isSuccessful()) {
            String responseUrl = response.body().string();
            return responseUrl;
        } else {
            throw new IOException("Unexpected code " + response);
        }
    }
    private static final String CHARSET_NAME = "UTF-8";
    /**
     * 这里使用了HttpClinet的API。只是为了方便
     * @param params
     * @return
     */
    public static String formatParams(List<BasicNameValuePair> params){
        return URLEncodedUtils.format(params, CHARSET_NAME);
    }
    /**
     * 为HttpGet 的 url 方便的添加多个name value 参数。
     * @param url
     * @param params
     * @return
     */
    public static String attachHttpGetParams(String url, List<BasicNameValuePair> params){
        return url + "?" + formatParams(params);
    }
    /**
     * 为HttpGet 的 url 方便的添加1个name value 参数。
     * @param url
     * @param name
     * @param value
     * @return
     */
    public static String attachHttpGetParam(String url, String name, String value){
        return url + "?" + name + "=" + value;
    }
}

GET 同步请求

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());
}

GET 异步请求

private final OkHttpClient client = new OkHttpClient();
 
public void run() throws Exception {
    Request request = new Request.Builder()
        .url("http://publicobject.com/helloworld.txt")
        .build();
 
    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());
      }
    });
}

设置超时时间

client.setConnectTimeout(10, TimeUnit.SECONDS);
client.setWriteTimeout(10, TimeUnit.SECONDS);
client.setReadTimeout(30, TimeUnit.SECONDS);

Okhttp的拦截器

注册一个应用拦截器通过 OkHttpClient.Builder调用 addInterceptor():

OkHttpClient client = new OkHttpClient.Builder()
    .addInterceptor(new LoggingInterceptor())
    .build();

Request request = new Request.Builder()
    .url("http://www.publicobject.com/helloworld.txt")
    .header("User-Agent", "OkHttp Example")
    .build();

Response response = client.newCall(request).execute();
response.body().close();
// .addNetworkInterceptor(new LoggingInterceptor())

LoggingInterceptor

class LoggingInterceptor implements Interceptor {
  @Override public Response intercept(Interceptor.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;
  }
}

Cache-Control

Cache-Control指定请求和响应遵循的缓存机制。在请求消息或响应消息中设置Cache-Control并不会修改另一个消息处理过程中的缓存处理过程。请求时的缓存指令有下几种：

1. Public指示响应可被任何缓存区缓存。
2. Private指示对于单个用户的整个或部分响应消息，不能被共享缓存处理。这允许服务器仅仅描述当用户的部分响应消息，此响应消息对于其他用户的请求无效。
3. no-cache指示请求或响应消息不能缓存
4. no-store用于防止重要的信息被无意的发布。在请求消息中发送将使得请求和响应消息都不使用缓存。
5. max-age指示客户机可以接收生存期不大于指定时间（以秒为单位）的响应。
6. min-fresh指示客户机可以接收响应时间小于当前时间加上指定时间的响应。
7. max-stale指示客户机可以接收超出超时期间的响应消息。如果指定max-stale消息的值，那么客户机可以接收超出超时期指定值之内的响应消息。

    final CacheControl.Builder builder = new CacheControl.Builder();
               builder.noCache();//不使用缓存，全部走网络
               builder.noStore();//不使用缓存，也不存储缓存
               builder.onlyIfCached();//只使用缓存
               builder.noTransform();//禁止转码
               builder.maxAge(10, TimeUnit.MILLISECONDS);//指示客户机可以接收生存期不大于指定时间的响应。
               builder.maxStale(10, TimeUnit.SECONDS);//指示客户机可以接收超出超时期间的响应消息
               builder.minFresh(10, TimeUnit.SECONDS);//指示客户机可以接收响应时间小于当前时间加上指定时间的响应。
               CacheControl cache = builder.build();//cacheControl
   
   
   
   
   OkHttpClient.Builder newBuilder = mOkHttpClient.newBuilder();
            newBuilder.addInterceptor(new Interceptor() {
               @Override
               public Response intercept(Chain chain) throws IOException {
                   Request request = chain.request();
                   boolean connected = NetworkUtil.isConnected(context);
                   if (!connected) {
                       request = request.newBuilder().cacheControl(CacheControl.FORCE_CACHE).build();
                   }
                   Response response = chain.proceed(request);
   
                   return response;
               }
           });

在Request中添加Token的拦截器

Interceptor mTokenInterceptor = new Interceptor() {
    @Override public Response intercept(Chain chain) throws IOException {
        Request originalRequest = chain.request();
        if (Your.sToken == null || alreadyHasAuthorizationHeader(originalRequest)) {
            return chain.proceed(originalRequest);
        }
        Request authorised = originalRequest.newBuilder()
            .header("Authorization", Your.sToken)
            .build();
        return chain.proceed(authorised);
    }
};

Okhttp 返回请求获取cookie

public class ReceivedCookiesInterceptor implements Interceptor {
    private Context context;

    public ReceivedCookiesInterceptor(Context context) {
        super();
        this.context = context;

    }

    @Override
    public Response intercept(Chain chain) throws IOException {
      
        Response originalResponse = chain.proceed(chain.request());
        //这里获取请求返回的cookie
        if (!originalResponse.headers("Set-Cookie").isEmpty()) {
            final StringBuffer cookieBuffer = new StringBuffer();
            //最近在学习RxJava,这里用了RxJava的相关API大家可以忽略,用自己逻辑实现即可.大家可以用别的方法保存cookie数据
            Observable.from(originalResponse.headers("Set-Cookie"))
                    .map(new Func1<String, String>() {
                        @Override
                        public String call(String s) {
                            String[] cookieArray = s.split(";");
                            return cookieArray[0];
                        }
                    })
                    .subscribe(new Action1<String>() {
                        @Override
                        public void call(String cookie) {
                            cookieBuffer.append(cookie).append(";");
                        }
                    });
            SharedPreferences sharedPreferences = context.getSharedPreferences("cookie", Context.MODE_PRIVATE);
            SharedPreferences.Editor editor = sharedPreferences.edit();
            editor.putString("cookie", cookieBuffer.toString());
            editor.commit();
        }

        return originalResponse;
    }

Okhttp 请求中添加cookie

public class AddCookiesInterceptor implements Interceptor {
    private Context context;

    public AddCookiesInterceptor(Context context) {
        super();
        this.context = context;

    }

    @Override
    public Response intercept(Chain chain) throws IOException {
        
        final Request.Builder builder = chain.request().newBuilder();
        SharedPreferences sharedPreferences = context.getSharedPreferences("cookie", Context.MODE_PRIVATE);
//最近在学习RxJava,这里用了RxJava的相关API大家可以忽略,用自己逻辑实现即可  
                Observable.just(sharedPreferences.getString("cookie", ""))
                .subscribe(new Action1<String>() {
                    @Override
                    public void call(String cookie) {
                        //添加cookie
                        builder.addHeader("Cookie", cookie);
                    }
                });
        return chain.proceed(builder.build());
    }
}