Android OkHttp彻底解析 是时候来了解OkHttp了

 

1、概述

最近在群里听到各类讨论okhttp的话题，可见okhttp的口碑至关好了。再加上Google貌似在6.0版本里面删除了HttpClient相关API，对于这个行为不作评价。为了更好的在应对网络访问，学习下okhttp仍是蛮必要的，本篇博客首先介绍okhttp的简单使用，主要包含：

• 通常的get请求
• 通常的post请求
• 基于Http的文件上传
• 文件下载
• 加载图片
• 支持请求回调，直接返回对象、对象集合
• 支持session的保持

最后会对上述几个功能进行封装，完整的封装类的地址见：https://github.com/hongyangAndroid/okhttp-utils

使用前，对于Android Studio的用户，能够选择添加:

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

或者Eclipse的用户，能够下载最新的jar okhttp he latest JAR ，添加依赖就能够用了。

注意:okhttp内部依赖okio，别忘了同时导入okio：

gradle: compile 'com.squareup.okio:okio:1.5.0'

最新的jar地址：okio the latest JAR

2、使用教程

（一）Http Get

对了网络加载库，那么最多见的确定就是http get请求了，好比获取一个网页的内容。

//建立okHttpClient对象
OkHttpClient mOkHttpClient = new OkHttpClient();
//建立一个Request
final Request request = new Request.Builder()
                .url("https://github.com/hongyangAndroid")
                .build();
//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();
            }
        });

1. 以上就是发送一个get请求的步骤，首先构造一个Request对象，参数最起码有个url，固然你能够经过Request.Builder设置更多的参数好比：header、method等。

2. 而后经过request的对象去构造获得一个Call对象，相似于将你的请求封装成了任务，既然是任务，就会有execute()和cancel()等方法。

3. 最后，咱们但愿以异步的方式去执行请求，因此咱们调用的是call.enqueue，将call加入调度队列，而后等待任务执行完成，咱们在Callback中便可获得结果。

看到这，你会发现，总体的写法仍是比较长的，因此封装确定是要作的，否则每一个请求这么写，得累死。

ok，须要注意几点：

• onResponse回调的参数是response，通常状况下，好比咱们但愿得到返回的字符串，能够经过response.body().string()获取；若是但愿得到返回的二进制字节数组，则调用response.body().bytes()；若是你想拿到返回的inputStream，则调用response.body().byteStream()

  看到这，你可能会奇怪，居然还能拿到返回的inputStream，看到这个最起码能意识到一点，这里支持大文件下载，有inputStream咱们就能够经过IO的方式写文件。不过也说明一个问题，这个onResponse执行的线程并非UI线程。的确是的，若是你但愿操做控件，仍是须要使用handler等，例如：

• @Override
  public void onResponse(final Response response) throws IOException
  {
        final String res = response.body().string();
        runOnUiThread(new Runnable()
        {
            @Override
            public void run()
            {
              mTv.setText(res);
            }
  
        });
  }

   

• 咱们这里是异步的方式去执行，固然也支持阻塞的方式，上面咱们也说了Call有一个execute()方法，你也能够直接调用call.execute()经过返回一个Response。

(二) Http Post 携带参数

看来上面的简单的get请求，基本上整个的用法也就掌握了，好比post携带参数，也仅仅是Request的构造的不一样。

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(){});

你们都清楚，post的时候，参数是包含在请求体中的；因此咱们经过FormEncodingBuilder。添加多个String键值对，而后去构造RequestBody，最后完成咱们Request的构造。

后面的就和上面同样了。

（三）基于Http的文件上传

接下来咱们在介绍一个能够构造RequestBody的Builder，叫作MultipartBuilder。当咱们须要作相似于表单上传的时候，就可使用它来构造咱们的requestBody。

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()
{
    //...
});

上述代码向服务器传递了一个键值对username:张鸿洋和一个文件。咱们经过MultipartBuilder的addPart方法能够添加键值对或者文件。

其实相似于咱们拼接模拟浏览器行为的方式，若是你对这块不了解，能够参考：从原理角度解析Android （Java） http 文件上传

ok，对于咱们最开始的目录还剩下图片下载，文件下载；这两个一个是经过回调的Response拿到byte[]而后decode成图片；文件下载，就是拿到inputStream作写文件操做，咱们这里就不赘述了。

关于用法，也能够参考泡网OkHttp使用教程

接下来咱们主要看如何封装上述的代码。

3、封装

因为按照上述的代码，写多个请求确定包含大量的重复代码，因此我但愿封装后的代码调用是这样的：

（一）使用

1. 通常的get请求

OkHttpClientManager.getAsyn("https://www.baidu.com", new OkHttpClientManager.ResultCallback<String>()
        {
            @Override
            public void onError(Request request, Exception e)
            {
                e.printStackTrace();
            }

            @Override
            public void onResponse(String u)
            {
                mTv.setText(u);//注意这里是UI线程
            }
        });

对于通常的请求，咱们但愿给个url，而后CallBack里面直接操做控件。

1. 文件上传且携带参数

咱们但愿提供一个方法，传入url,params,file,callback便可。

OkHttpClientManager.postAsyn("http://192.168.1.103:8080/okHttpServer/fileUpload",//
    new OkHttpClientManager.ResultCallback<String>()
    {
        @Override
        public void onError(Request request, IOException e)
        {
            e.printStackTrace();
        }

        @Override
        public void onResponse(String result)
        {

        }
    },//
    file,//
    "mFile",//
    new OkHttpClientManager.Param[]{
            new OkHttpClientManager.Param("username", "zhy"),
            new OkHttpClientManager.Param("password", "123")}
        );

1. 键值对没什么说的，参数3为file，参数4为file对应的name，这个name不是文件的名字； 
   对应于http中的

   <input type="file" name="mFile" >

   对应的是name后面的值，即mFile.

2. 文件下载

   对于文件下载，提供url，目标dir，callback便可。

OkHttpClientManager.downloadAsyn(
    "http://192.168.1.103:8080/okHttpServer/files/messenger_01.png",    
    Environment.getExternalStorageDirectory().getAbsolutePath(), 
new OkHttpClientManager.ResultCallback<String>()
    {
        @Override
        public void onError(Request request, IOException e)
        {

        }

        @Override
        public void onResponse(String response)
        {
            //文件下载成功，这里回调的reponse为文件的absolutePath
        }
});

展现图片

展现图片，咱们但愿提供一个url和一个imageview，若是下载成功，直接帮咱们设置上便可。

OkHttpClientManager.displayImage(mImageView, 
     "http://images.csdn.net/20150817/1.jpg");

1. 内部会自动根据imageview的大小自动对图片进行合适的压缩。虽然，这里可能不适合一次性加载大量图片的场景，可是对于app中偶尔有几个图片的加载，仍是可用的。

4、整合Gson

不少人提出项目中使用时，服务端返回的是Json字符串，但愿客户端回调能够直接拿到对象，因而整合进入了Gson，完善该功能。

（一）直接回调对象

例如如今有个User实体类：

package com.zhy.utils.http.okhttp;

public class User {

    public String username ; 
    public String password  ;

    public User() {
        // TODO Auto-generated constructor stub
    }

    public User(String username, String password) {
        this.username = username;
        this.password = password;
    }

    @Override
    public String toString()
    {
        return "User{" +
                "username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

服务端返回：

{"username":"zhy","password":"123"}

客户端能够以下方式调用：

OkHttpClientManager.getAsyn("http://192.168.56.1:8080/okHttpServer/user!getUser",
new OkHttpClientManager.ResultCallback<User>()
{
    @Override
    public void onError(Request request, Exception e)
    {
        e.printStackTrace();
    }

    @Override
    public void onResponse(User user)
    {
        mTv.setText(u.toString());//UI线程
    }
});

咱们传入泛型User，在onResponse里面直接回调User对象。 
这里特别要注意的事，若是在json字符串->实体对象过程当中发生错误，程序不会崩溃，onError方法会被回调。

注意：这里作了少量的更新，接口命名从StringCallback修改成ResultCallback。接口中的onFailure方法修改成onError。

(二) 回调对象集合

依然是上述的User类，服务端返回

[{"username":"zhy","password":"123"},{"username":"lmj","password":"12345"}]

则客户端能够以下调用：

OkHttpClientManager.getAsyn("http://192.168.56.1:8080/okHttpServer/user!getUsers",
new OkHttpClientManager.ResultCallback<List<User>>()
{
    @Override
    public void onError(Request request, Exception e)
    {
        e.printStackTrace();
    }
    @Override
    public void onResponse(List<User> us)
    {
        Log.e("TAG", us.size() + "");
        mTv.setText(us.get(1).toString());
    }
});

惟一的区别，就是泛型变为List<User> ，ok ， 若是发现bug或者有任何意见欢迎留言。

源码

ok，基本介绍完了，对于封装的代码其实也很简单，我就直接贴出来了，由于也没什么好介绍的，若是你看完上面的用法，确定能够看懂：

package com.zhy.utils.http.okhttp;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.os.Looper;
import android.widget.ImageView;

import com.google.gson.Gson;
import com.google.gson.internal.$Gson$Types;
import com.squareup.okhttp.Call;
import com.squareup.okhttp.Callback;
import com.squareup.okhttp.FormEncodingBuilder;
import com.squareup.okhttp.Headers;
import com.squareup.okhttp.MediaType;
import com.squareup.okhttp.MultipartBuilder;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.RequestBody;
import com.squareup.okhttp.Response;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.net.CookieManager;
import java.net.CookiePolicy;
import java.net.FileNameMap;
import java.net.URLConnection;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
 * Created by zhy on 15/8/17.
 */
public class OkHttpClientManager
{
    private static OkHttpClientManager mInstance;
    private OkHttpClient mOkHttpClient;
    private Handler mDelivery;
    private Gson mGson;


    private static final String TAG = "OkHttpClientManager";

    private OkHttpClientManager()
    {
        mOkHttpClient = new OkHttpClient();
        //cookie enabled
        mOkHttpClient.setCookieHandler(new CookieManager(null, CookiePolicy.ACCEPT_ORIGINAL_SERVER));
        mDelivery = new Handler(Looper.getMainLooper());
        mGson = new Gson();
    }

    public static OkHttpClientManager getInstance()
    {
        if (mInstance == null)
        {
            synchronized (OkHttpClientManager.class)
            {
                if (mInstance == null)
                {
                    mInstance = new OkHttpClientManager();
                }
            }
        }
        return mInstance;
    }

    /**
     * 同步的Get请求
     *
     * @param url
     * @return Response
     */
    private Response _getAsyn(String url) throws IOException
    {
        final Request request = new Request.Builder()
                .url(url)
                .build();
        Call call = mOkHttpClient.newCall(request);
        Response execute = call.execute();
        return execute;
    }

    /**
     * 同步的Get请求
     *
     * @param url
     * @return 字符串
     */
    private String _getAsString(String url) throws IOException
    {
        Response execute = _getAsyn(url);
        return execute.body().string();
    }


    /**
     * 异步的get请求
     *
     * @param url
     * @param callback
     */
    private void _getAsyn(String url, final ResultCallback callback)
    {
        final Request request = new Request.Builder()
                .url(url)
                .build();
        deliveryResult(callback, request);
    }


    /**
     * 同步的Post请求
     *
     * @param url
     * @param params post的参数
     * @return
     */
    private Response _post(String url, Param... params) throws IOException
    {
        Request request = buildPostRequest(url, params);
        Response response = mOkHttpClient.newCall(request).execute();
        return response;
    }


    /**
     * 同步的Post请求
     *
     * @param url
     * @param params post的参数
     * @return 字符串
     */
    private String _postAsString(String url, Param... params) throws IOException
    {
        Response response = _post(url, params);
        return response.body().string();
    }

    /**
     * 异步的post请求
     *
     * @param url
     * @param callback
     * @param params
     */
    private void _postAsyn(String url, final ResultCallback callback, Param... params)
    {
        Request request = buildPostRequest(url, params);
        deliveryResult(callback, request);
    }

    /**
     * 异步的post请求
     *
     * @param url
     * @param callback
     * @param params
     */
    private void _postAsyn(String url, final ResultCallback callback, Map<String, String> params)
    {
        Param[] paramsArr = map2Params(params);
        Request request = buildPostRequest(url, paramsArr);
        deliveryResult(callback, request);
    }

    /**
     * 同步基于post的文件上传
     *
     * @param params
     * @return
     */
    private Response _post(String url, File[] files, String[] fileKeys, Param... params) throws IOException
    {
        Request request = buildMultipartFormRequest(url, files, fileKeys, params);
        return mOkHttpClient.newCall(request).execute();
    }

    private Response _post(String url, File file, String fileKey) throws IOException
    {
        Request request = buildMultipartFormRequest(url, new File[]{file}, new String[]{fileKey}, null);
        return mOkHttpClient.newCall(request).execute();
    }

    private Response _post(String url, File file, String fileKey, Param... params) throws IOException
    {
        Request request = buildMultipartFormRequest(url, new File[]{file}, new String[]{fileKey}, params);
        return mOkHttpClient.newCall(request).execute();
    }

    /**
     * 异步基于post的文件上传
     *
     * @param url
     * @param callback
     * @param files
     * @param fileKeys
     * @throws IOException
     */
    private void _postAsyn(String url, ResultCallback callback, File[] files, String[] fileKeys, Param... params) throws IOException
    {
        Request request = buildMultipartFormRequest(url, files, fileKeys, params);
        deliveryResult(callback, request);
    }

    /**
     * 异步基于post的文件上传，单文件不带参数上传
     *
     * @param url
     * @param callback
     * @param file
     * @param fileKey
     * @throws IOException
     */
    private void _postAsyn(String url, ResultCallback callback, File file, String fileKey) throws IOException
    {
        Request request = buildMultipartFormRequest(url, new File[]{file}, new String[]{fileKey}, null);
        deliveryResult(callback, request);
    }

    /**
     * 异步基于post的文件上传，单文件且携带其余form参数上传
     *
     * @param url
     * @param callback
     * @param file
     * @param fileKey
     * @param params
     * @throws IOException
     */
    private void _postAsyn(String url, ResultCallback callback, File file, String fileKey, Param... params) throws IOException
    {
        Request request = buildMultipartFormRequest(url, new File[]{file}, new String[]{fileKey}, params);
        deliveryResult(callback, request);
    }

    /**
     * 异步下载文件
     *
     * @param url
     * @param destFileDir 本地文件存储的文件夹
     * @param callback
     */
    private void _downloadAsyn(final String url, final String destFileDir, final ResultCallback callback)
    {
        final Request request = new Request.Builder()
                .url(url)
                .build();
        final Call call = mOkHttpClient.newCall(request);
        call.enqueue(new Callback()
        {
            @Override
            public void onFailure(final Request request, final IOException e)
            {
                sendFailedStringCallback(request, e, callback);
            }

            @Override
            public void onResponse(Response response)
            {
                InputStream is = null;
                byte[] buf = new byte[2048];
                int len = 0;
                FileOutputStream fos = null;
                try
                {
                    is = response.body().byteStream();
                    File file = new File(destFileDir, getFileName(url));
                    fos = new FileOutputStream(file);
                    while ((len = is.read(buf)) != -1)
                    {
                        fos.write(buf, 0, len);
                    }
                    fos.flush();
                    //若是下载文件成功，第一个参数为文件的绝对路径
                    sendSuccessResultCallback(file.getAbsolutePath(), callback);
                } catch (IOException e)
                {
                    sendFailedStringCallback(response.request(), e, callback);
                } finally
                {
                    try
                    {
                        if (is != null) is.close();
                    } catch (IOException e)
                    {
                    }
                    try
                    {
                        if (fos != null) fos.close();
                    } catch (IOException e)
                    {
                    }
                }

            }
        });
    }

    private String getFileName(String path)
    {
        int separatorIndex = path.lastIndexOf("/");
        return (separatorIndex < 0) ? path : path.substring(separatorIndex + 1, path.length());
    }

    /**
     * 加载图片
     *
     * @param view
     * @param url
     * @throws IOException
     */
    private void _displayImage(final ImageView view, final String url, final int errorResId)
    {
        final Request request = new Request.Builder()
                .url(url)
                .build();
        Call call = mOkHttpClient.newCall(request);
        call.enqueue(new Callback()
        {
            @Override
            public void onFailure(Request request, IOException e)
            {
                setErrorResId(view, errorResId);
            }

            @Override
            public void onResponse(Response response)
            {
                InputStream is = null;
                try
                {
                    is = response.body().byteStream();
                    ImageUtils.ImageSize actualImageSize = ImageUtils.getImageSize(is);
                    ImageUtils.ImageSize imageViewSize = ImageUtils.getImageViewSize(view);
                    int inSampleSize = ImageUtils.calculateInSampleSize(actualImageSize, imageViewSize);
                    try
                    {
                        is.reset();
                    } catch (IOException e)
                    {
                        response = _getAsyn(url);
                        is = response.body().byteStream();
                    }

                    BitmapFactory.Options ops = new BitmapFactory.Options();
                    ops.inJustDecodeBounds = false;
                    ops.inSampleSize = inSampleSize;
                    final Bitmap bm = BitmapFactory.decodeStream(is, null, ops);
                    mDelivery.post(new Runnable()
                    {
                        @Override
                        public void run()
                        {
                            view.setImageBitmap(bm);
                        }
                    });
                } catch (Exception e)
                {
                    setErrorResId(view, errorResId);

                } finally
                {
                    if (is != null) try
                    {
                        is.close();
                    } catch (IOException e)
                    {
                        e.printStackTrace();
                    }
                }
            }
        });


    }

    private void setErrorResId(final ImageView view, final int errorResId)
    {
        mDelivery.post(new Runnable()
        {
            @Override
            public void run()
            {
                view.setImageResource(errorResId);
            }
        });
    }


    //*************对外公布的方法************


    public static Response getAsyn(String url) throws IOException
    {
        return getInstance()._getAsyn(url);
    }


    public static String getAsString(String url) throws IOException
    {
        return getInstance()._getAsString(url);
    }

    public static void getAsyn(String url, ResultCallback callback)
    {
        getInstance()._getAsyn(url, callback);
    }

    public static Response post(String url, Param... params) throws IOException
    {
        return getInstance()._post(url, params);
    }

    public static String postAsString(String url, Param... params) throws IOException
    {
        return getInstance()._postAsString(url, params);
    }

    public static void postAsyn(String url, final ResultCallback callback, Param... params)
    {
        getInstance()._postAsyn(url, callback, params);
    }


    public static void postAsyn(String url, final ResultCallback callback, Map<String, String> params)
    {
        getInstance()._postAsyn(url, callback, params);
    }


    public static Response post(String url, File[] files, String[] fileKeys, Param... params) throws IOException
    {
        return getInstance()._post(url, files, fileKeys, params);
    }

    public static Response post(String url, File file, String fileKey) throws IOException
    {
        return getInstance()._post(url, file, fileKey);
    }

    public static Response post(String url, File file, String fileKey, Param... params) throws IOException
    {
        return getInstance()._post(url, file, fileKey, params);
    }

    public static void postAsyn(String url, ResultCallback callback, File[] files, String[] fileKeys, Param... params) throws IOException
    {
        getInstance()._postAsyn(url, callback, files, fileKeys, params);
    }


    public static void postAsyn(String url, ResultCallback callback, File file, String fileKey) throws IOException
    {
        getInstance()._postAsyn(url, callback, file, fileKey);
    }


    public static void postAsyn(String url, ResultCallback callback, File file, String fileKey, Param... params) throws IOException
    {
        getInstance()._postAsyn(url, callback, file, fileKey, params);
    }

    public static void displayImage(final ImageView view, String url, int errorResId) throws IOException
    {
        getInstance()._displayImage(view, url, errorResId);
    }


    public static void displayImage(final ImageView view, String url)
    {
        getInstance()._displayImage(view, url, -1);
    }

    public static void downloadAsyn(String url, String destDir, ResultCallback callback)
    {
        getInstance()._downloadAsyn(url, destDir, callback);
    }

    //****************************


    private Request buildMultipartFormRequest(String url, File[] files,
                                              String[] fileKeys, Param[] params)
    {
        params = validateParam(params);

        MultipartBuilder builder = new MultipartBuilder()
                .type(MultipartBuilder.FORM);

        for (Param param : params)
        {
            builder.addPart(Headers.of("Content-Disposition", "form-data; name=\"" + param.key + "\""),
                    RequestBody.create(null, param.value));
        }
        if (files != null)
        {
            RequestBody fileBody = null;
            for (int i = 0; i < files.length; i++)
            {
                File file = files[i];
                String fileName = file.getName();
                fileBody = RequestBody.create(MediaType.parse(guessMimeType(fileName)), file);
                //TODO 根据文件名设置contentType
                builder.addPart(Headers.of("Content-Disposition",
                                "form-data; name=\"" + fileKeys[i] + "\"; filename=\"" + fileName + "\""),
                        fileBody);
            }
        }

        RequestBody requestBody = builder.build();
        return new Request.Builder()
                .url(url)
                .post(requestBody)
                .build();
    }

    private String guessMimeType(String path)
    {
        FileNameMap fileNameMap = URLConnection.getFileNameMap();
        String contentTypeFor = fileNameMap.getContentTypeFor(path);
        if (contentTypeFor == null)
        {
            contentTypeFor = "application/octet-stream";
        }
        return contentTypeFor;
    }


    private Param[] validateParam(Param[] params)
    {
        if (params == null)
            return new Param[0];
        else return params;
    }

    private Param[] map2Params(Map<String, String> params)
    {
        if (params == null) return new Param[0];
        int size = params.size();
        Param[] res = new Param[size];
        Set<Map.Entry<String, String>> entries = params.entrySet();
        int i = 0;
        for (Map.Entry<String, String> entry : entries)
        {
            res[i++] = new Param(entry.getKey(), entry.getValue());
        }
        return res;
    }

    private static final String SESSION_KEY = "Set-Cookie";
    private static final String mSessionKey = "JSESSIONID";

    private Map<String, String> mSessions = new HashMap<String, String>();

    private void deliveryResult(final ResultCallback callback, Request request)
    {
        mOkHttpClient.newCall(request).enqueue(new Callback()
        {
            @Override
            public void onFailure(final Request request, final IOException e)
            {
                sendFailedStringCallback(request, e, callback);
            }

            @Override
            public void onResponse(final Response response)
            {
                try
                {
                    final String string = response.body().string();
                    if (callback.mType == String.class)
                    {
                        sendSuccessResultCallback(string, callback);
                    } else
                    {
                        Object o = mGson.fromJson(string, callback.mType);
                        sendSuccessResultCallback(o, callback);
                    }


                } catch (IOException e)
                {
                    sendFailedStringCallback(response.request(), e, callback);
                } catch (com.google.gson.JsonParseException e)//Json解析的错误
                {
                    sendFailedStringCallback(response.request(), e, callback);
                }

            }
        });
    }

    private void sendFailedStringCallback(final Request request, final Exception e, final ResultCallback callback)
    {
        mDelivery.post(new Runnable()
        {
            @Override
            public void run()
            {
                if (callback != null)
                    callback.onError(request, e);
            }
        });
    }

    private void sendSuccessResultCallback(final Object object, final ResultCallback callback)
    {
        mDelivery.post(new Runnable()
        {
            @Override
            public void run()
            {
                if (callback != null)
                {
                    callback.onResponse(object);
                }
            }
        });
    }

    private Request buildPostRequest(String url, Param[] params)
    {
        if (params == null)
        {
            params = new Param[0];
        }
        FormEncodingBuilder builder = new FormEncodingBuilder();
        for (Param param : params)
        {
            builder.add(param.key, param.value);
        }
        RequestBody requestBody = builder.build();
        return new Request.Builder()
                .url(url)
                .post(requestBody)
                .build();
    }


    public static abstract class ResultCallback<T>
    {
        Type mType;

        public ResultCallback()
        {
            mType = getSuperclassTypeParameter(getClass());
        }

        static Type getSuperclassTypeParameter(Class<?> subclass)
        {
            Type superclass = subclass.getGenericSuperclass();
            if (superclass instanceof Class)
            {
                throw new RuntimeException("Missing type parameter.");
            }
            ParameterizedType parameterized = (ParameterizedType) superclass;
            return $Gson$Types.canonicalize(parameterized.getActualTypeArguments()[0]);
        }

        public abstract void onError(Request request, Exception e);

        public abstract void onResponse(T response);
    }

    public static class Param
    {
        public Param()
        {
        }

        public Param(String key, String value)
        {
            this.key = key;
            this.value = value;
        }

        String key;
        String value;
    }


}

源码地址okhttp-utils，你们能够本身下载查看。