25 Nov 2015 /

Android OkHttp完全解析是时候来了解OkHttp了

转载请标明出处：

http://blog.csdn.net/lmj623565791/article/details/47911083；

本文出自:【张鸿洋的博客】

一、概述

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

一般的get请求

一般的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，可以选择添加:

compile 'com.squareup.okhttp:okhttp:2.4.0'1

或者Eclipse的用户，可以下载最新的jar okhttp he latest JAR ，添加依赖就可以用了。

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

二、使用教程

（一）Http Get

对了网络加载库，那么最常见的肯定就是http get请求了，比如获取一个网页的内容。

//创建okHttpClient对象OkHttpClient mOkHttpClient = new OkHttpClient();//创建一个Requestfinal Request request = new Request.Builder()

.url("https://github.com/hongyangAndroid")

.build();//new callCall 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();

}

});

123456789101112131415161718192021222324

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，当然你可以通过Request.Builder设置更多的参数比如：header、method等。

然后通过request的对象去构造得到一个Call对象，类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。

最后，我们希望以异步的方式去执行请求，所以我们调用的是call.enqueue，将call加入调度队列，然后等待任务执行完成，我们在Callback中即可得到结果。

看到这，你会发现，整体的写法还是比较长的，所以封装肯定是要做的，不然每个请求这么写，得累死。

ok，需要注意几点：

onResponse回调的参数是response，一般情况下，比如我们希望获得返回的字符串，可以通过response.body().string()获取；如果希望获得返回的二进制字节数组，则调用response.body().bytes()；如果你想拿到返回的inputStream，则调用response.body().byteStream()

看到这，你可能会奇怪，竟然还能拿到返回的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我们就可以通过IO的方式写文件。不过也说明一个问题，这个onResponse执行的线程并不是UI线程。的确是的，如果你希望操作控件，还是需要使用handler等，例如：

@Overridepublic void onResponse(final Response response) throws IOException

{ final String res = response.body().string();

runOnUiThread(new Runnable()

{ @Override

public void run()

{

mTv.setText(res);

}

});

}

我们这里是异步的方式去执行，当然也支持阻塞的方式，上面我们也说了Call有一个execute()方法，你也可以直接调用call.execute()通过返回一个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，比如post携带参数，也仅仅是Request的构造的不同。

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(){});12345678910

大家都清楚，post的时候，参数是包含在请求体中的；所以我们通过FormEncodingBuilder。添加多个String键值对，然后去构造RequestBody，最后完成我们Request的构造。

后面的就和上面一样了。

（三）基于Http的文件上传

接下来我们在介绍一个可以构造RequestBody的Builder，叫做MultipartBuilder。当我们需要做类似于表单上传的时候，就可以使用它来构造我们的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()

{ //...});1234567891011121314151617181920212223242526

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。我们通过MultipartBuilder的addPart方法可以添加键值对或者文件。

其实类似于我们拼接模拟浏览器行为的方式，如果你对这块不了解，可以参考：从原理角度解析Android （Java） http 文件上传

ok，对于我们最开始的目录还剩下图片下载，文件下载；这两个一个是通过回调的Response拿到byte[]然后decode成图片；文件下载，就是拿到inputStream做写文件操作，我们这里就不赘述了。

关于用法，也可以参考泡网OkHttp使用教程

接下来我们主要看如何封装上述的代码。

三、封装

由于按照上述的代码，写多个请求肯定包含大量的重复代码，所以我希望封装后的代码调用是这样的：

（一）使用

一般的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

}

});

对于一般的请求，我们希望给个url，然后CallBack里面直接操作控件。

文件上传且携带参数

我们希望提供一个方法，传入url,params,file,callback即可。

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")}

);

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

对应的是name后面的值，即mFile.

文件下载

对于文件下载，提供url，目标dir，callback即可。

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

}

});

展示图片

展示图片，我们希望提供一个url和一个imageview，如果下载成功，直接帮我们设置上即可。

OkHttpClientManager.displayImage(mImageView,

"http://images.csdn.net/20150817/1.jpg");

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，但是对于app中偶尔有几个图片的加载，还是可用的。

四、整合Gson

很多人提出项目中使用时，服务端返回的是Json字符串，希望客户端回调可以直接拿到对象，于是整合进入了Gson，完善该功能。

（一）直接回调对象

例如现在有个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 + '\'' + '}';

}

}12345678910111213141516171819202122232425

服务端返回：

{"username":"zhy","password":"123"}1

客户端可以如下方式调用：

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

}

});123456789101112131415

我们传入泛型User，在onResponse里面直接回调User对象。

这里特别要注意的事，如果在json字符串->实体对象过程中发生错误，程序不会崩溃，onError方法会被回调。

注意：这里做了少许的更新，接口命名从StringCallback修改为ResultCallback。接口中的onFailure方法修改为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"}]1

则客户端可以如下调用：

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());

}

});123456789101112131415

唯一的区别，就是泛型变为List<User> ，ok ，如果发现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，因为也没什么好介绍的，如果你看完上面的用法，肯定可以看懂：

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，单文件且携带其他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(); //如果下载文件成功，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，大家可以自己下载查看。

Android OkHttp完全解析是时候来了解OkHttp了

发布评论

热门评论区：

Android 异步消息处理机制让你深入理解 Looper、Handler、Message三者关系

Activity四种启动模式