Android开发之OkHttp的使用
本篇记录的是Android开发中OkHttp框架的使用。OkHttp是Java中用于网络请求的一个库，主页为：http://square.github.io/okhttp/， github地址为：https://github.com/square/okhttp
下面介绍OkHttp库的用法，本篇会给出OkHttp的使用demo，demo中包含了常用的get请求、post请求、文件的上传和下载，demo运行的效果如下图所示：
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：
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'
}
（1）GET请求
最简单的GET请求用法如下：
//简单的Get请求，不带参数
public void simpleGetClick(View view) {
okHttpClient = new OkHttpClient();
Request request = new Request.Builder()
.url("http://192.168.1.170:8088/okhttp/test_simple_get.php")
.build();
okHttpClient.newCall(request).enqueue(callback);
}//带参数的Get请求
public void addParamGetClick(View view) {
okHttpClient = new OkHttpClient();
Request request = new Request.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：
//请求后的回调接口
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);
}
};（2）POST请求
比较简单的POST请求，用法如下：
//简单的带参数和Header的post请求
public void simplePostClick(View view) {
okHttpClient = new OkHttpClient();
RequestBody requestBody = new FormBody.Builder()
.add("username", "wangwu")
.add("password", "hello12345")
.add("gender", "female")
.build();
Request request = new Request.Builder()
.url("http://192.168.1.170:8088/okhttp/test_simple_post.php")
.post(requestBody)
.addHeader("token", "helloworldhelloworldhelloworld")
.build();
okHttpClient.newCall(request).enqueue(callback);
}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：
//带文本参数和文件参数的post请求
public void filePostClick(View view) {
RequestBody fileBody = RequestBody.create(MediaType.parse("text/plain; charset=utf-8"), tempFile);
RequestBody requestBody = new MultipartBody.Builder()
.setType(MultipartBody.FORM)
.addFormDataPart("username", "wangwu")
.addFormDataPart("password", "hello12345")
.addFormDataPart("gender", "female")
.addFormDataPart("file", "info.txt", fileBody)
.build();
Request request = new Request.Builder()
.url("http://192.168.1.170:8088/okhttp/test_param_post.php")
.post(requestBody)
.addHeader("token", "helloworldhelloworldhelloworld")
.build();
okHttpClient.newCall(request).enqueue(callback);
}（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;
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);
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
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
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
progressListener.update(bytesWritten, contentLength, bytesWritten == contentLength);
}
};
}
}
//进度回调接口
interface ProgressListener {
void update(long bytesRead, long contentLength, boolean done);
}
}
（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);
}
}
参考：http://blog.csdn.net/lmj623565791/article/details/47911083
Demo下载