关于OkHttp的基本使用

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

使用okhttp需要导入okhttp jar包和okio!

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Request
final Request request = new Request.Builder()
                .url("https://github.com/luojunquan")
                .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,当然你可以通过Request.Builder设置更多的参数比如:header、method等。
  2. 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。
  3. 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。

需要注意以下几点:

  • nResponse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()

  • 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:

  • @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);
    }

    });
    

    }

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","罗小贱");

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

注: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。

基于Http的文件上传

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, "罗小贱"))
 .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()
{
    //...
});

注: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。

封装

一般的get请求

OkHttpClientManager.getAsyn("https://www.baidu.com", new OkHttpClientManager.ResultCallback()
    {
        @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
        }
    });

注: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

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()
{
    @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")}
    );

注: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.

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()
{
    @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");

注: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。

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。

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 + '\'' +
            '}';
        }
}`

服务端返回:

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

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()
{
    @Override
    public void onError(Request request, Exception e)
    {
        e.printStackTrace();
    }

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

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。

回调对象集合

依然是上述的User类,服务端返回

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

唯一的区别,就是泛型变为List

`    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 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 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 params)
{
    if (params == null) return new Param[0];
    int size = params.size();
    Param[] res = new Param[size];
    Set> entries = params.entrySet();
    int i = 0;
    for (Map.Entry 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 mSessions = new HashMap();

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
{
    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;
    }
}`

你可能感兴趣的:(关于OkHttp的基本使用)