android-async-http是一个强大的第三方开源网络请求库，

官网源码：https://github.com/loopj/android-async-http

官网教程：http://loopj.com/android-async-http/

这个网络请求库是基于Apache HttpClient库之上的一个异步网络请求处理库，网络处理均基于Android的非UI线程，通过回调方法处理请求结果。

主要类介绍

AsyncHttpRequest

继承自Runnabler，被submit至线程池执行网络请求并发送start，success等消息

AsyncHttpResponseHandler

接收请求结果，一般重写onSuccess及onFailure接收请求成功或失败的消息，还有onStart，onFinish等消息

TextHttpResponseHandler

继承自AsyncHttpResponseHandler，只是重写了AsyncHttpResponseHandler的onSuccess和onFailure方法，将请求结果由byte数组转换为String

JsonHttpResponseHandler

继承自TextHttpResponseHandler，同样是重写onSuccess和onFailure方法，将请求结果由String转换为JSONObject或JSONArray

BaseJsonHttpResponseHandler

继承自TextHttpResponseHandler，是一个泛型类，提供了parseResponse方法，子类需要提供实现，将请求结果解析成需要的类型，子类可以灵活地使用解析方法，可以直接原始解析，使用gson等。

RequestParams

请求参数，可以添加普通的字符串参数，并可添加File，InputStream上传文件

AsyncHttpClient

核心类，使用HttpClient执行网络请求，提供了get，put，post，delete，head等请求方法，使用起来很简单，只需以url及RequestParams调用相应的方法即可，还可以选择性地传入Context，用于取消Content相关的请求，同时必须提供ResponseHandlerInterface（AsyncHttpResponseHandler继承自ResponseHandlerInterface）的实现类，一般为AsyncHttpResponseHandler的子类，AsyncHttpClient内部有一个线程池，当使用AsyncHttpClient执行网络请求时，最终都会调用sendRequest方法，在这个方法内部将请求参数封装成AsyncHttpRequest（继承自Runnable）交由内部的线程池执行。

SyncHttpClient

继承自AsyncHttpClient，同步执行网络请求，AsyncHttpClient把请求封装成AsyncHttpRequest后提交至线程池，SyncHttpClient把请求封装成AsyncHttpRequest后直接调用它的run方法。

服务器端php测试代码：

<?php
$data = array(
'status'=>'success',
'get'=>json_encode($_GET),
'post'=>json_encode($_POST),
'upload'=>json_encode($_FILES)
);
echo json_encode($data);?>

android客户端测试代码：

package com.penngo.http;import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.AsyncHttpResponseHandler;
import com.loopj.android.http.FileAsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;public class HttpUtil {private static final String BASE_URL = "http://192.168.17.99/";private static AsyncHttpClient client = new AsyncHttpClient();public static void setTimeout(){client.setTimeout(60000);}public static void get(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {client.get(getAbsoluteUrl(url), params, responseHandler);}public static void post(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {client.post(getAbsoluteUrl(url), params, responseHandler);}public static void download(String url, RequestParams params, FileAsyncHttpResponseHandler fileAsyncHttpResponseHandler){client.get(getAbsoluteUrl(url), params, fileAsyncHttpResponseHandler);}private static String getAbsoluteUrl(String relativeUrl) {return BASE_URL + relativeUrl;}
}

package com.penngo.http;import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;import com.loopj.android.http.FileAsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;
import com.loopj.android.http.TextHttpResponseHandler;import org.apache.http.Header;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Locale;public class MainActivity extends Activity {private final static String tag = "MainActivity-->";@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Button getBtn = (Button)this.findViewById(R.id.getBtn);getBtn.setOnClickListener(new View.OnClickListener() {public void onClick(View v) {testGet();}});Button postBtn = (Button)this.findViewById(R.id.postBtn);postBtn.setOnClickListener(new View.OnClickListener() {public void onClick(View v) {testPost();}});Button upLoadBtn = (Button)this.findViewById(R.id.upLoadBtn);upLoadBtn.setOnClickListener(new View.OnClickListener(){public void onClick(View v){testUploadFile();}});Button downloadBtn = (Button)this.findViewById(R.id.downloadBtn);downloadBtn.setOnClickListener(new View.OnClickListener() {public void onClick(View v) {testDownloadFile();}});}private void testGet(){HttpUtil.get("test/android.php", getParames(), responseHandler);}private RequestParams getParames(){RequestParams params = new RequestParams();params.put("user", "penngo");params.put("psw", "penngo");return params;}private TextHttpResponseHandler responseHandler =  new TextHttpResponseHandler(){@Overridepublic void onStart() {Log.e(tag, "onStart====");}@Overridepublic void onSuccess(int statusCode, Header[] headers, String response) {Log.e(tag, "onSuccess====");StringBuilder builder = new StringBuilder();for (Header h : headers) {String _h = String.format(Locale.US, "%s : %s", h.getName(), h.getValue());builder.append(_h);builder.append("\n");}Log.e(tag, "statusCode:" + statusCode + " headers:" + builder.toString() + " response:" + response);}@Overridepublic void onFailure(int statusCode, Header[] headers, String errorResponse, Throwable e) {Log.e(tag, "onFailure====");StringBuilder builder = new StringBuilder();for (Header h : headers) {String _h = String.format(Locale.US, "%s : %s", h.getName(), h.getValue());builder.append(_h);builder.append("\n");}Log.e(tag, "statusCode:" + statusCode + " headers:" + builder.toString(), e);}@Overridepublic void onRetry(int retryNo) {// called when request is retried}};private void testPost(){HttpUtil.post("test/android.php", getParames(), responseHandler);}private void testUploadFile(){RequestParams params = new RequestParams();try {InputStream is = this.getAssets().open("png/launcher.png");String png = this.getExternalCacheDir().getAbsolutePath() + "/launcher.png";File myFile = new File(png);Log.e(tag, "png====" + png);this.copyToSD(png, "png/launcher.png");params.put("pngFile", myFile, RequestParams.APPLICATION_OCTET_STREAM);} catch(Exception e) {Log.e(tag,"上传失败", e);}HttpUtil.post("test/android.php", params, responseHandler);}private void testDownloadFile(){String mp3 = this.getExternalCacheDir().getAbsolutePath() + "/fa.mp3";File mp3File = new File(mp3);FileAsyncHttpResponseHandler fileHandler = new FileAsyncHttpResponseHandler(mp3File){public void onSuccess(int statusCode, Header[] headers, File file){Log.e(tag, "onSuccess====");StringBuilder builder = new StringBuilder();for (Header h : headers) {String _h = String.format(Locale.US, "%s : %s", h.getName(), h.getValue());builder.append(_h);builder.append("\n");}Log.e(tag, "statusCode:" + statusCode + " headers:" + builder.toString() + " file:" + file.getAbsolutePath());}public void onFailure(int statusCode, Header[] headers, Throwable throwable, File file){}};HttpUtil.download("test/fa.mp3", null, fileHandler);}/*** 复制文件到sdcard*/private void copyToSD(String strOut, String srcInput) throws IOException{InputStream myInput;OutputStream myOutput = new FileOutputStream(strOut);myInput = this.getAssets().open(srcInput);byte[] buffer = new byte[1024];int length = myInput.read(buffer);while(length > 0){myOutput.write(buffer, 0, length);length = myInput.read(buffer);}myOutput.flush();myInput.close();myOutput.close();}
}

执行输出结果：

E/MainActivity-->﹕ onStart====

E/MainActivity-->﹕ onSuccess====

E/MainActivity-->﹕ statusCode:200 headers:Date : Wed, 05 Aug 2015 04:30:00 GMT

Server : Apache/2.2.25 (Win32) mod_ssl/2.2.25 OpenSSL/0.9.8y mod_wsgi/3.3 Python/2.7.3

X-Powered-By : ZendServer 6.3.0

Set-Cookie : ZDEDebuggerPresent=php,phtml,php3; path=/

Keep-Alive : timeout=5, max=100

Connection : Keep-Alive

Transfer-Encoding : chunked

Content-Type : text/html

response:{"status":"success","get":"{\"user\":\"penngo\",\"psw\":\"penngo\"}","post":"[]","upload":"[]"}

E/MainActivity-->﹕ onStart====

E/MainActivity-->﹕ onSuccess====

E/MainActivity-->﹕ statusCode:200 headers:Date : Wed, 05 Aug 2015 04:30:15 GMT

Server : Apache/2.2.25 (Win32) mod_ssl/2.2.25 OpenSSL/0.9.8y mod_wsgi/3.3 Python/2.7.3

X-Powered-By : ZendServer 6.3.0

Set-Cookie : ZDEDebuggerPresent=php,phtml,php3; path=/

Keep-Alive : timeout=5, max=100

Connection : Keep-Alive

Transfer-Encoding : chunked

Content-Type : text/html

response:{"status":"success","get":"[]","post":"{\"user\":\"penngo\",\"psw\":\"penngo\"}","upload":"[]"}

E/MainActivity-->﹕ png====/mnt/sdcard/Android/data/com.penngo.http/cache/launcher.png

E/MainActivity-->﹕ onStart====

E/MainActivity-->﹕ onSuccess====

E/MainActivity-->﹕ statusCode:200 headers:Date : Wed, 05 Aug 2015 04:30:24 GMT

Server : Apache/2.2.25 (Win32) mod_ssl/2.2.25 OpenSSL/0.9.8y mod_wsgi/3.3 Python/2.7.3

X-Powered-By : ZendServer 6.3.0

Set-Cookie : ZDEDebuggerPresent=php,phtml,php3; path=/

Keep-Alive : timeout=5, max=100

Connection : Keep-Alive

Transfer-Encoding : chunked

Content-Type : text/html

response:{"status":"success","get":"[]","post":"[]","upload":"{\"pngFile\":{\"name\":\"launcher.png\",\"type\":\"application\\\/octet-stream\",\"tmp_name\":\"C:\\\\Windows\\\\Temp\\\\phpFDC4.tmp\",\"error\":0,\"size\":3418}}"}

E/MainActivity-->﹕ onSuccess====

E/MainActivity-->﹕ statusCode:200 headers:Date : Wed, 05 Aug 2015 04:30:30 GMT

Server : Apache/2.2.25 (Win32) mod_ssl/2.2.25 OpenSSL/0.9.8y mod_wsgi/3.3 Python/2.7.3

Last-Modified : Fri, 19 Dec 2014 08:10:00 GMT

ETag : "13200000000a25c-4776aa-50a8d3c355700"

Accept-Ranges : bytes

Content-Length : 4683434

Keep-Alive : timeout=5, max=100

Connection : Keep-Alive

Content-Type : audio/mpeg

file:/mnt/sdcard/Android/data/com.penngo.http/cache/fa.mp3