OKHTTP网络请求——上传下载

http://www.open-open.com/lib/view/open1462258981866.html

http://www.2cto.com/kf/201604/500820.html

概念：okHttp 是同步请求。

noHttp 是异步请求

下面上代码一一说明：

要使用OkHttp，必须在项目中先导入OkHttp，在app模块的build.gradle文件中，加入下面的代码：

?

1

2

3

4

5

6

dependencies {

    compile fileTree(dir: 'libs', include: ['*.jar'])

    testCompile'junit:junit:4.12'

    compile'com.android.support:appcompat-v7:23.1.1'

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

}

这样就将OkHttp导入到项目中了。

 

（1）GET请求

最简单的GET请求用法如下：

 

?

1

2

3

4

5

6

7

8

//简单的Get请求，不带参数

publicvoidsimpleGetClick(View view) {

    okHttpClient = newOkHttpClient();

    Request request = newRequest.Builder()

            .url("http://192.168.1.170:8088/okhttp/test_simple_get.php")

            .build();

    okHttpClient.newCall(request).enqueue(callback);

}

如果请求中要添加Header头和参数，可以用下面的方式：

 

 

?

1

2

3

4

5

6

7

8

9

//带参数的Get请求

publicvoidaddParamGetClick(View view) {

    okHttpClient = newOkHttpClient();

    Request request = newRequest.Builder()

            .addHeader("token","asdlfjkasdljfaskdjfalsjkljalk") //请求头中加入参数

            .url("http://192.168.1.170:8088/okhttp/test_param_get.php?username=zhangsan&phone=13888888888") //携带参数

            .build();

    okHttpClient.newCall(request).enqueue(callback);

}

需要注意的是，上面的代码中，callback是请求后的回调接口，代码如下：

?

1

2

3

4

5

6

7

8

9

10

11

12

//请求后的回调接口

privateCallback callback = newCallback() {

    @Override

    publicvoidonFailure(Call call, IOException e) {

        setResult(e.getMessage(),false);

    }

 

    @Override

    publicvoidonResponse(Call call, Response response) throwsIOException {

        setResult(response.body().string(),true);

    }

};

这个回调接口需要注意的是，onResponse和onFailure都不是在UI线程中执行的，所以如果我们要在onResponse或onFailure中进行UI相关的操作，需要在UI线程中进行。

（2）POST请求

比较简单的POST请求，用法如下：

 

?

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

//简单的带参数和Header的post请求

publicvoidsimplePostClick(View view) {

    okHttpClient = newOkHttpClient();

    RequestBody requestBody = newFormBody.Builder()

            .add("username","wangwu")

            .add("password","hello12345")

            .add("gender","female")

            .build();

    Request request = newRequest.Builder()

            .url("http://192.168.1.170:8088/okhttp/test_simple_post.php")

            .post(requestBody)

            .addHeader("token","helloworldhelloworldhelloworld")

            .build();

    okHttpClient.newCall(request).enqueue(callback);

}

这里我们需要先构造一个RequestBody，然后把需要携带的参数放到RequestBody中，然后使用这个RequestBody构建一个Request请求，最后将这个请求放入队列中执行

 

如果我们的POST请求稍微复杂点，比如携带的参数既有文本类型的，又有文件类型的，那么可以用下面的方式来请求：

 

?

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

//带文本参数和文件参数的post请求

publicvoidfilePostClick(View view) {

    RequestBody fileBody = RequestBody.create(MediaType.parse("text/plain; charset=utf-8"), tempFile);

    RequestBody requestBody = newMultipartBody.Builder()

            .setType(MultipartBody.FORM)

            .addFormDataPart("username","wangwu")

            .addFormDataPart("password","hello12345")

            .addFormDataPart("gender","female")

            .addFormDataPart("file","info.txt", fileBody)

            .build();

    Request request = newRequest.Builder()

            .url("http://192.168.1.170:8088/okhttp/test_param_post.php")

            .post(requestBody)

            .addHeader("token","helloworldhelloworldhelloworld")

            .build();

    okHttpClient.newCall(request).enqueue(callback);

}

上面的代码中，tempFile是一个文本文件，为了POST提交文件和一些其他的参数，我们使用MultipartBody来构建一个请求体，需要注意的是，因为POST的内容含有文件，所以我们必须为这个请求体设置setType(MultipartBody.FORM)

（3）文件的上传

文件上传并显示进度，这个代码稍微有些复杂，下面直接上代码：

package com.test.testokhttp; import android.os.Environment;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.ProgressBar;import android.widget.TextView;import android.widget.Toast; import java.io.File;import java.io.IOException;import java.util.concurrent.TimeUnit; import okhttp3.Call;import okhttp3.Callback;import okhttp3.Interceptor;import okhttp3.MediaType;import okhttp3.MultipartBody;import okhttp3.OkHttpClient;import okhttp3.Request;import okhttp3.RequestBody;import okhttp3.Response;import okhttp3.ResponseBody;import okio.Buffer;import okio.BufferedSink;import okio.BufferedSource;import okio.ForwardingSink;import okio.ForwardingSource;import okio.Okio;import okio.Sink;import okio.Source; /** 使用okHttp 上传文件并显示进度 */public class UploadActivity extends AppCompatActivity {     private OkHttpClient okHttpClient;    private TextView resultTextView;    private ProgressBar progressBar;    private File tempFile;     @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_upload);        setTitle("上传文件并显示进度");         resultTextView = (TextView) findViewById(R.id.result_textview);        progressBar = (ProgressBar) findViewById(R.id.progress_bar);        progressBar.setMax(100);         okHttpClient = new OkHttpClient.Builder()                .readTimeout(30, TimeUnit.SECONDS)                .connectTimeout(10, TimeUnit.SECONDS)                .writeTimeout(60, TimeUnit.SECONDS)                .build();    }     //点击按钮开始上传文件    public void startUploadClick(View view) {        tempFile = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "test.pdf");        RequestBody requestBody = new MultipartBody.Builder()                .setType(MultipartBody.FORM)                .addFormDataPart("file", "test.pdf", RequestBody.create(MediaType.parse("application/pdf; charset=utf-8"), tempFile))                .build();        ProgressRequestBody progressRequestBody = new ProgressRequestBody(requestBody, progressListener);//通过对RequestBody的包装，实现对上传进度的监听(携带了一个接口的引用)        Request request = new Request.Builder()                .url("http://192.168.1.170:8088/okhttp/test_upload_file.php")                .post(progressRequestBody)                .build();        okHttpClient.newCall(request).enqueue(callback);    }     //通过实现进度回调接口中的方法，来显示进度.   通过回调机制实现了线程间的通讯。//原理是，将回调类定义为一个实现某种接口的类（接口可以省掉），然后在每个多线程类上都注入一个回调对象。当线程执行完毕后，通过回调对象执行自己的回调方法，从而达到线程通信的目的。//白话（我把我的引用给你，你干完了某事，调用我的方法）    private ProgressListener progressListener = new ProgressListener() {        @Override        public void update(long bytesRead, long contentLength, boolean done) {            int progress = (int) (100.0 * bytesRead / contentLength);            progressBar.setProgress(progress);        }    };     //请求后的回调方法    private Callback callback = new Callback() {        @Override        public void onFailure(Call call, IOException e) {            setResult(e.getMessage(), false);        }         @Override        public void onResponse(Call call, Response response) throws IOException {            setResult(response.body().string(), true);        }    };     //显示请求返回的结果（在主线程）    private void setResult(final String msg, final boolean success) {        runOnUiThread(new Runnable() {            @Override            public void run() {                if (success) {                    Toast.makeText(UploadActivity.this, "请求成功", Toast.LENGTH_SHORT).show();                } else {                    Toast.makeText(UploadActivity.this, "请求失败", Toast.LENGTH_SHORT).show();                }                resultTextView.setText(msg);            }        });    }     //自定义的RequestBody，能够显示进度    public class ProgressRequestBody extends RequestBody {        //实际的待包装请求体        private final RequestBody requestBody;        //进度回调接口        private final ProgressListener progressListener;        //包装完成的BufferedSink        private BufferedSink bufferedSink;         /**         * 构造函数，赋值         *         * @param requestBody      待包装的请求体         * @param progressListener 回调接口         */        public ProgressRequestBody(RequestBody requestBody, ProgressListener progressListener) {            this.requestBody = requestBody;            this.progressListener = progressListener;        }         /**         * 重写调用实际的响应体的contentType         *         * @return MediaType         */        @Override        public MediaType contentType() {            return requestBody.contentType();        }         /**         * 重写调用实际的响应体的contentLength         *         * @return contentLength         * @throws IOException 异常         */        @Override        public long contentLength() throws IOException {            return requestBody.contentLength();        }         /**         * 重写进行写入         *         * @param sink BufferedSink         * @throws IOException 异常         */        @Override        public void writeTo(BufferedSink sink) throws IOException {            if (bufferedSink == null) {                //包装                bufferedSink = Okio.buffer(sink(sink));            }            //写入            requestBody.writeTo(bufferedSink);            //必须调用flush，否则最后一部分数据可能不会被写入            bufferedSink.flush();         }         /**         * 写入，回调进度接口         *         * @param sink Sink         * @return Sink         */        private Sink sink(Sink sink) {            return new ForwardingSink(sink) {                //当前写入字节数                long bytesWritten = 0L;                //总字节长度，避免多次调用contentLength()方法                long contentLength = 0L;                 @Override                public void write(Buffer source, long byteCount) throws IOException {                    super.write(source, byteCount);                    if (contentLength == 0) {                        //获得contentLength的值，后续不再调用                        contentLength = contentLength();                    }                    //增加当前写入的字节数                    bytesWritten += byteCount;                    //回调（在子线程中回调，在主线程中修改ui）                    progressListener.update(bytesWritten, contentLength, bytesWritten == contentLength);                }            };        }    }     //进度回调接口    interface ProgressListener {        void update(long bytesRead, long contentLength, boolean done);    } }

上面需要注意的是，上传文件需要实现自定义的RequestBody，也就是上面的ProgressRequestBody，在ProgressRequestBody中获取上传的进度。

（4）文件的下载

下载和上传类似，区别在于，需要我们实习自定义的ResponseBody而不是RequestBody了，下面上代码：

import android.os.Environment;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.ProgressBar;import android.widget.TextView;import android.widget.Toast; import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.util.concurrent.TimeUnit; import okhttp3.Call;import okhttp3.Callback;import okhttp3.Interceptor;import okhttp3.MediaType;import okhttp3.OkHttpClient;import okhttp3.Request;import okhttp3.Response;import okhttp3.ResponseBody;import okio.Buffer;import okio.BufferedSource;import okio.ForwardingSource;import okio.Okio;import okio.Source; public class DownloadActivity extends AppCompatActivity {     private OkHttpClient okHttpClient;    private TextView resultTextView;    private ProgressBar progressBar;    private File tempFile;     @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_download);        setTitle("下载文件并显示进度");         okHttpClient = new OkHttpClient.Builder()                .addNetworkInterceptor(new Interceptor() {                    @Override public Response intercept(Interceptor.Chain chain) throws IOException {                        Response originalResponse = chain.proceed(chain.request());                        return originalResponse.newBuilder()                                .body(new ProgressResponseBody(originalResponse.body(), progressListener))                                .build();                    }                })                .connectTimeout(5, TimeUnit.SECONDS)                .readTimeout(300, TimeUnit.SECONDS)                .writeTimeout(30, TimeUnit.SECONDS)                .build();        resultTextView = (TextView) findViewById(R.id.result_textview);        progressBar = (ProgressBar) findViewById(R.id.progress_bar);        tempFile = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + System.currentTimeMillis() + ".pdf");    }     //下载文件    public void startDownloadClick(View view) {        Request request = new Request.Builder()                .url("http://192.168.1.170:8088/okhttp/test.pdf")                .build();        okHttpClient.newCall(request).enqueue(callback);    }     private ProgressListener progressListener = new ProgressListener() {        @Override        public void update(long bytesRead, long contentLength, boolean done) {            int progress = (int) (100.0 * bytesRead / contentLength);            progressBar.setProgress(progress);        }    };     //请求后的回调方法    private Callback callback = new Callback() {        @Override        public void onFailure(Call call, IOException e) {            setResult(e.getMessage(), false);        }         @Override        public void onResponse(Call call, Response response) throws IOException {            if(response != null) {                //下载完成，保存数据到文件                InputStream is = response.body().byteStream();                FileOutputStream fos = new FileOutputStream(tempFile);                byte[] buf = new byte[1024];                int hasRead = 0;                while((hasRead = is.read(buf)) > 0) {                    fos.write(buf, 0, hasRead);                }                fos.close();                is.close();                setResult("下载成功", true);            }        }    };     //显示请求返回的结果    private void setResult(final String msg, final boolean success) {        runOnUiThread(new Runnable() {            @Override            public void run() {                if (success) {                    Toast.makeText(DownloadActivity.this, "请求成功", Toast.LENGTH_SHORT).show();                } else {                    Toast.makeText(DownloadActivity.this, "请求失败", Toast.LENGTH_SHORT).show();                }                resultTextView.setText(msg);            }        });    }         //自定义的ResponseBody，在其中处理进度    private static class ProgressResponseBody extends ResponseBody {         private final ResponseBody responseBody;        private final ProgressListener progressListener;        private BufferedSource bufferedSource;         public ProgressResponseBody(ResponseBody responseBody, ProgressListener progressListener) {            this.responseBody = responseBody;            this.progressListener = progressListener;        }         @Override public MediaType contentType() {            return responseBody.contentType();        }         @Override public long contentLength() {            return responseBody.contentLength();        }         @Override public BufferedSource source() {            if (bufferedSource == null) {                bufferedSource = Okio.buffer(source(responseBody.source()));            }            return bufferedSource;        }         private Source source(Source source) {            return new ForwardingSource(source) {                long totalBytesRead = 0L;                 @Override public long read(Buffer sink, long byteCount) throws IOException {                    long bytesRead = super.read(sink, byteCount);                    // read() returns the number of bytes read, or -1 if this source is exhausted.                    totalBytesRead += bytesRead != -1 ? bytesRead : 0;                    progressListener.update(totalBytesRead, responseBody.contentLength(), bytesRead == -1);                    return bytesRead;                }            };        }    }     //进度回调接口    interface ProgressListener {        void update(long bytesRead, long contentLength, boolean done);    }}

如果我们在项目中直接使用上面的代码来进行http请求的话，势必会比较麻烦，所以这里我们需要封装上面的代码，尽量在项目中能用简短的代码完成网络请求。另外，一个项目中肯定会有很多个网络请求，我们没必要在每次网络请求中都创建一个OkHttpClient对象，所有的请求公用一个OkHttpClient就可以了。