Android OKHttp網絡框架

好久沒逛簡書了。這周公司的項目也已經愉快的迭代了新版本，對於之前一直存留的東西一直沒怎么梳理，今天想說說這兩年特別火的網絡框架。okhttp我想大部分Android開發者都不陌生，因為它的到來。是我們Android開發者的一個福音，像之前我們一直都在用volley網絡請求 、android-async-http、xUtils框架等等，他們都有自己的優勢，詳細使用我在這里就不一一介紹了，Github有很多這樣的Demo、畢竟咱今天主要說的是okhttp，相比於上面說的那些，okhttp的使用就更多具體，好用，在業界的口碑也是非常好。再加上Google已經在6.0版本里面刪除了HttpClient相關API，如果有些開發者還是想用的話只能自己手動添加jar包了。我覺得為了更好的在應對目前流行的網絡訪問，了解使用okhttp還是非常有必要的，開始進入正題：

OKhttp官網

• 在使用的時候，對於咱們Android Studio的用戶，先添加依賴庫:

compile 'com.squareup.okhttp:okhttp:2.7.0'
compile 'com.squareup.okio:okio:1.7.0'

• 或者使用使用以下這個，這個結合Retrofit(retrofit就是對okhttp做了一層封裝。把網絡請求都交給給了Okhttp，我們只需要通過簡單的配置就能使用retrofit來進行網絡請求)使用會更靈活，下次有時間把這個可以做一遍文章寫出來。\

compile 'com.squareup.okhttp3:okhttp:3.2.0'

Get請求

在OKHttp中，每一次網絡請求就是一個Request，我們只要在Request里填寫我們需要的url，header等其他參數，再通過Request構造出Call，Call內部去請求參數，得到回復，並將返回調用者。即可

1.同步，異步請求

先聲明 OkHttpClient client = new OkHttpClient();
然后在子線程去執行以下操作（因為android本身是不能在主線程做網絡請求操作的，這樣會阻塞UI線程因此我們需要自己開啟一個線程）
    Request request = new Request.Builder()
     .url("https://www.baidu.com/")
     .build();
   Response response = client.newCall(request).execute();
   if(response.isSuccessful()){
         Log.i("MainActivity",response.code());
         Log.i("MainActivity",response.body().string());
           }
     }，
- 異步請求的話改一丟丟就行了
client.newCall(request).enqueue(new Callback() {
 @Override
 public void onFailure(Request request, IOException e) {
 }
 @Override
 public void onResponse(Response response) throws IOException {
       //NOT UI Thread
       if(response.isSuccessful()){
       Log.i("MainActivity",response.code());
       Log.i("MainActivity",response.body().string());
     }
   }
 });
大致步驟就是這樣了

2.POST請求

在進行post請求的時候，我們一般都是需要添加參數和header，甚至有請求的id和key

· 傳入header
  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();
· 使用RequestBody添加參數，類似表單提交
  RequestBody formBody = new FormEncodingBuilder()
        .add("name", "zhangsan") .add("password", "123456")
        .add("subject", "subjectmit")
        .build();
  Request request = new Request.Builder()
        .url(url)
        .post(body)
        .build();
· 在傳入header或者post參數都是傳到Request里，最后的調用方式也和上面的GET方式一樣
  Response response = client.newCall(request)
               .
 if (response.isSuccessful()) {
           return response.body().string(); 
  }else {
           throw new IOException("Unexpected code " + response);
 }
· 上面是異步請求的方式，如果是異步的話execute()改成enqueue就行了

3.還有文件上傳下載，提交表達等操作，都在以下代碼中進行了簡單的封裝

package com.lukey.okhttp_demo;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.os.Looper;
import com.squareup.okhttp.Callback;
import com.squareup.okhttp.FormEncodingBuilder;
import com.squareup.okhttp.MediaType;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.RequestBody;
import com.squareup.okhttp.Response;
import org.json.JSONObject;
import java.io.IOException;
import java.util.Map;

/**
 * creator  Lukey on 2016/8/9
 */
public class OKManager {
    private OkHttpClient mClient;
    private volatile static OKManager manager;
    private final String TAG = OKManager.class.getSimpleName();
    private Handler mHandler;
    //提交Json數據
    private static final MediaType JSON = MediaType.parse("application/json;charset=utf-8");
    //提交字符串
    private static final MediaType MEDIA_TYPE_MARKWODN = MediaType.parse("text/x-markdown;charset=utf-8");
    public OKManager() {
        mClient = new OkHttpClient();
        mHandler = new Handler(Looper.getMainLooper());
    }
    //采用單例模式獲取對象
    public static OKManager getInstance() {
        OKManager instance = null;
        if (manager == null) {
            synchronized (OKManager.class) {
                if (instance == null) {
                    instance = new OKManager();
                    manager = instance;
                }
            }
        }
        return instance;
    }
    /**
     * 同步請求，在android開發中不常用，因為會阻塞UI線程
     * @param url
     * @return     
  */
    private String syncGetByURL(String url) {
        //構建一個request請求
        Request request = new Request.Builder().url(url).build();
        Response response = null;
        try {
            response = mClient.newCall(request).execute();
//同步請求數據
            if (response.isSuccessful()) {
                return response.body().string();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    /**
     * 請求指定的URL返回的結果是json字符串
     *
     * @param url
     * @param callBack
     */
    public void asyncJsonStringByURL(String url, final Func1 callBack) {
        final Request request = new Request.Builder().url(url).build();
        mClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Request request, IOException e) {
                e.printStackTrace();
            }
            @Override
            public void onResponse(Response response) throws IOException {
                if (response != null && response.isSuccessful()) {
                    onSuccessJsonStringMethod(response.body().string(), callBack);
                }
            }
        });
    }
    /**
     * 請求返回的json對象
     *
     * @param url
     * @param callBack
     */
    public void asyncJsonObjectByURL(String url, final Func4 callBack) {
        final Request request = new Request.Builder().url(url).build();
        mClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Request request, IOException e) {
                e.printStackTrace();
            }
            @Override
            public void onResponse(Response response) throws IOException {
                if (response != null && response.isSuccessful()) {
                    onSuccessJsonObjectMethod(request.body().toString(), callBack);
                }
            }
        });
    }
    /**
     * 請求返回的字節對象
     *
     * @param url
     * @param callBack
     */
    public void asyncGetByteURL(String url, final Func2 callBack) {
        final Request request = new Request.Builder().url(url).build();
        mClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Request request, IOException e) {
                e.printStackTrace();
            }
            @Override
            public void onResponse(Response response) throws IOException {
                if (response != null && response.isSuccessful()) {
                    onSuccessByteMethod(response.body().bytes(), callBack);
                }
            }
        }); 
   }
    /**
     * 請求返回的結果是一個imageview類型 bitmap類型
     *
     * @param url
     * @param callBack
     */
    public void asyncDownLoadIamgeByURL(String url, final Func3 callBack) {
        final Request request = new Request.Builder().url(url).build();
        mClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Request request, IOException e) {
                e.printStackTrace();
            }
            @Override
            public void onResponse(Response response) throws IOException {
                if (response != null && response.isSuccessful()) {
                    byte[] data = response.body().bytes();
                    Bitmap bitmap = new
             CropSquareTrans().transform(BitmapFactory.decodeByteArray(data, 0, data.length));
                    callBack.onResponse(bitmap);
                }
            }
        });
    }
    /**
     * 模擬表單提交
     *
     * @param url
     * @param params
     * @param callBack
     */
    public void sendComplexForm(String url, Map<String, String> params, final Func4 callBack) {
        FormEncodingBuilder formEncodingBuilder = new FormEncodingBuilder();
//表單對象
        if (params != null && !params.isEmpty()) {
            for (Map.Entry<String, String> entry : params.entrySet()) {
                formEncodingBuilder.add(entry.getKey(), entry.getValue());
            }
        }
        RequestBody requestBody = formEncodingBuilder.build();
        //采用post方式提交
        Request request = new Request.Builder().url(url).post(requestBody).build();
        mClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Request request, IOException e) {
                e.printStackTrace();
            }
            @Override
            public void onResponse(Response response) throws IOException {
                if (response != null && response.isSuccessful()) {
                    onSuccessJsonObjectMethod(response.body().string(), callBack);
                }
            }
        });
    }
    /**
     * 向服務器提交String請求
     *
     * @param url
     * @param content
     * @param callBack
     */
    public void sendStringByPostMethod(String url, String content, final Func4 callBack) {        
          final Request request = new Request.Builder()
          .url(url).post(RequestBody.create(MEDIA_TYPE_MARKWODN, content)).build();
          mClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Request request, IOException e) {
                e.printStackTrace();
            }
            @Override
            public void onResponse(Response response) throws IOException {
                if (request != null && response.isSuccessful()) {
                    onSuccessJsonObjectMethod(response.body().string(), callBack); 
               }
            }
        });
    }
    /**
     * 請求返回的結果是json字符串
     *
     * @param jsonValue
     * @param callBack
     */
    private void onSuccessJsonStringMethod(final String jsonValue, final Func1 callBack) {
        mHandler.post(new Runnable() {
            @Override
            public void run() {
                if (callBack != null) {
                    try {
                        callBack.onResponse(jsonValue);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        });
    }
    /**
     * 返回響應的結果是json對象
     *
     * @param jsonValue
     * @param callBack
     */
    private void onSuccessJsonObjectMethod(final String jsonValue, final Func4 callBack) {
        mHandler.post(new Runnable() {
            @Override
            public void run() {
                if (callBack != null) {
                    try {
                        callBack.onResponse(new JSONObject(jsonValue));
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                } 
           }
        });
    }
    /**
     * 返回響應的是byte[] 數組
     *
     * @param data
     * @param callBack
     */
    private void onSuccessByteMethod(final byte[] data, final Func2 callBack) {
        mHandler.post(new Runnable() {
            @Override
            public void run() {
                if (callBack != null) {
                    callBack.onResponse(data);
                }
            }
        });
    }

    //     定義四個接口，對外部調用
    interface Func1 {
        void onResponse(String result);
    }
    interface Func2 {
        void onResponse(byte[] result);
    }
    interface Func3 {
        void onResponse(Bitmap bitmap);
    }
    interface Func4 {
        void onResponse(JSONObject jsonObject);
    }
}

4.最后在補充一個緩存數據的代碼

· 先設置一個路徑
private static String savePath = Environment.getExternalStorageDirectory()
      .getAbsolutePath() + "/mydata/dataCash";

private static File mCashFile = new File(savePath);
private static int mCacheSize = 20 * 1024 * 1024;

private static final Interceptor REWRITE_CACHE_CONTROL_INTERCEPTOR = new Interceptor() {
      @Override
      public Response intercept(Chain chain) throws IOException {
          Request request = chain.request();
          if (!ConnectionUtil.isConnection(LdApplication.getInstance())) {
              request = request.newBuilder()
                      .cacheControl(CacheControl.FORCE_CACHE)
                      .build();
          } else {
              request = request.newBuilder()
                      .cacheControl(CacheControl.FORCE_NETWORK)
                      .build();
          }
          Response originalResponse = chain.proceed(request);
          if (ConnectionUtil.isConnection(LdApplication.getInstance())) {
              //有網的時候讀接口上的@Headers里的配置，可以在這里進行統一的設置
              String cacheControl = request.cacheControl().toString();
              return originalResponse.newBuilder()
                      .header("Cache-Control", cacheControl)
                      .removeHeader("Pragma")
                      .build();
          } else {
              return originalResponse.newBuilder()
                      .header("Cache-Control",
                               "public, only-if-cached, max-stale=2419200")
                      .removeHeader("Pragma")
                      .build(); 
         }
      }
  };

· 以下設置持久化Cookie
public static void setCookie() {
  mClient.setCookieHandler(new CookieManager(
          new PersistentCookieStore(MyApplication.getInstance()),
          CookiePolicy.ACCEPT_ALL));
}
MyApplication.getInstance() ---->在Application用單例的方式實現

5.在主界面中調用

public class MainActivity extends AppCompatActivity {
    private Button mButton;
    private final static String TAG = MainActivity.class.getSimpleName();
    private OKManager mOKManager;

    private String image_path = "http://pic.mmfile.net/thumbs/2016/06/66970_13a13_236.jpg";
    private String json_path = "http://api.avatardata.cn/Weather/Query?key=d79f47b8dcb74eb78ea3d74b88876145&cityname=%E6%B7%B1%E5%9C%B3";

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mButton = (Button) this.findViewById(R.id.button);

    mOKManager = OKManager.getInstance();
    mButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        mOKManager.asyncJsonStringByURL(json_path, new OKManager.Func1() {
            @Override
            public void onResponse(String result) {
                Logger.json(result.toString());
                Log.d(TAG,result);
            }
        });
    }});
  }
}
· 布局很簡單一個點擊按鈕和一個顯示文本
· 然后別忘了在配置文件中添加權限哦~~~~
  <uses-permission android:name="android.permission.INTERNET"/>