Android 如何使用Http协议访问网络
Android使用Http协议访问网络主要有两种方式,一个是使用 java.net.*(标准Java接口),另一个是使用 Org.apache接口。
java.net.*:中是可以认为是JDK中的java网络处理包,提供了流,Socket,网络协议等常见网络相关类。
Apache HttpClient:是一个开源项目,功能相对与JDK中的更加完善,可以为客户端提供高效丰富的Http编程支持
一:使用java.net包来进行Http协议的网络编程
public class CustomHttpURLConnection { private static String TAG = "CustomHttpUrlConnection"; //代表 客户端与服务器之间的一个Http连接 private static HttpURLConnection conn; public CustomHttpURLConnection() { } /** * 向服务器发送Get请求 * @param strUrl 发送Get请求的url地址 * @param nameValuePairs get请求参数 * @return */ public static String GetFromWebByHttpUrlConnection(String strUrl, NameValuePair... nameValuePairs) { String result=""; try { //1.新建Url对象 URL url = new URL(strUrl); //2.获取并设置HttpURLConnection对象 conn = (HttpURLConnection) url.openConnection(); conn.setDoInput(true); conn.setConnectTimeout(3000); conn.setReadTimeout(4000); conn.setRequestProperty("accept", "*/*"); //3.连接服务器 conn.connect(); //4.从建立好的连接中获取inputStream InputStream stream=conn.getInputStream(); //5.为了更好的读取inputStream中的数据,包装inputStream InputStreamReader inReader=new InputStreamReader(stream); BufferedReader buffer=new BufferedReader(inReader); //6.开始读取数据 String strLine=null; while((strLine=buffer.readLine())!=null) { result+=strLine; } //7.关闭出入流 inReader.close(); //8.关闭连接 conn.disconnect(); return result; } catch (MalformedURLException e) { Log.e(TAG, "getFromWebByHttpUrlCOnnection:"+e.getMessage()); e.printStackTrace(); return null; } catch (IOException e) { Log.e(TAG, "getFromWebByHttpUrlCOnnection:"+e.getMessage()); e.printStackTrace(); return null; } } /** * 向服务器发送Post请求 * @param strUrl * @param nameValuePairs * @return */ public static String PostFromWebByHttpURLConnection(String strUrl, NameValuePair... nameValuePairs) { String result=""; try { URL url = new URL(strUrl); conn = (HttpURLConnection) url .openConnection(); // 设置是否从httpUrlConnection读入,默认情况下是true; conn.setDoInput(true); // 设置是否向httpUrlConnection输出,因为这个是post请求,参数要放在 // http正文内,因此需要设为true, 默认情况下是false; conn.setDoOutput(true); // 设定请求的方法为"POST",默认是GET conn.setRequestMethod("POST"); //设置超时 conn.setConnectTimeout(3000); conn.setReadTimeout(4000); // Post 请求不能使用缓存 conn.setUseCaches(false); conn.setInstanceFollowRedirects(true); // 设定传送的内容类型是可序列化的java对象 // (如果不设此项,在传送序列化对象时,当WEB服务默认的不是这种类型时可能抛java.io.EOFException) conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); // 连接,从上述第2条中url.openConnection()至此的配置必须要在connect之前完成, conn.connect(); InputStream in = conn.getInputStream(); InputStreamReader inStream=new InputStreamReader(in); BufferedReader buffer=new BufferedReader(inStream); String strLine=null; while((strLine=buffer.readLine())!=null) { result+=strLine; } return result; } catch (IOException ex) { Log.e(TAG,"PostFromWebByHttpURLConnection:"+ ex.getMessage()); ex.printStackTrace(); return null; } } }
二:使用Apache HttpClient
public class CustomHttpClient { private static String TAG = "CustomHttpClient"; private static final CommonLog log = LogFactory.createLog(); private static final String CHARSET_UTF8 = HTTP.UTF_8; private static final String CHARSET_GB2312 = "GB2312"; private static HttpClient customerHttpClient; private CustomHttpClient() { } /** * HttpClient post方法 * * @param url * @param nameValuePairs * @return */ public static String PostFromWebByHttpClient(Context context, String url, NameValuePair... nameValuePairs) { try { List<NameValuePair> params = new ArrayList<NameValuePair>(); if (nameValuePairs != null) { for (int i = 0; i < nameValuePairs.length; i++) { params.add(nameValuePairs[i]); } } UrlEncodedFormEntity urlEncoded = new UrlEncodedFormEntity(params, CHARSET_UTF8); HttpPost httpPost = new HttpPost(url); httpPost.setEntity(urlEncoded); HttpClient client = getHttpClient(context); HttpResponse response = client.execute(httpPost); if (response.getStatusLine().getStatusCode() != HttpStatus.SC_OK) { throw new RuntimeException("请求失败"); } HttpEntity resEntity = response.getEntity(); return (resEntity == null) ? null : EntityUtils.toString(resEntity, CHARSET_UTF8); } catch (UnsupportedEncodingException e) { Log.w(TAG, e.getMessage()); return null; } catch (ClientProtocolException e) { Log.w(TAG, e.getMessage()); return null; } catch (IOException e) { throw new RuntimeException(context.getResources().getString( R.string.httpError), e); } } public static String getFromWebByHttpClient(Context context, String url, NameValuePair... nameValuePairs) throws Exception{ log.d("getFromWebByHttpClient url = " + url); try { // http地址 // String httpUrl = // "http://192.168.1.110:8080/httpget.jsp?par=HttpClient_android_Get"; StringBuilder sb = new StringBuilder(); sb.append(url); if (nameValuePairs != null && nameValuePairs.length > 0) { sb.append("?"); for (int i = 0; i < nameValuePairs.length; i++) { if (i > 0) { sb.append("&"); } sb.append(String.format("%s=%s", nameValuePairs[i].getName(), nameValuePairs[i].getValue())); } } // HttpGet连接对象 HttpGet httpRequest = new HttpGet(sb.toString()); // 取得HttpClient对象 HttpClient httpclient = getHttpClient(context); // 请求HttpClient,取得HttpResponse HttpResponse httpResponse = httpclient.execute(httpRequest); // 请求成功 if (httpResponse.getStatusLine().getStatusCode() != HttpStatus.SC_OK) { throw new RuntimeException(context.getResources().getString( R.string.httpError)); } return EntityUtils.toString(httpResponse.getEntity()); } catch (ParseException e) { // TODO Auto-generated catch block throw new RuntimeException(context.getResources().getString( R.string.httpError),e); } catch (IOException e) { // TODO Auto-generated catch block log.e("IOException "); e.printStackTrace(); throw new RuntimeException(context.getResources().getString( R.string.httpError),e); } } /** * 创建httpClient实例 * * @return * @throws Exception */ private static synchronized HttpClient getHttpClient(Context context) { if (null == customerHttpClient) { HttpParams params = new BasicHttpParams(); // 设置一些基本参数 HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1); HttpProtocolParams.setContentCharset(params, CHARSET_UTF8); HttpProtocolParams.setUseExpectContinue(params, true); HttpProtocolParams .setUserAgent( params, "Mozilla/5.0(Linux;U;Android 2.2.1;en-us;Nexus One Build.FRG83) " + "AppleWebKit/553.1(KHTML,like Gecko) Version/4.0 Mobile Safari/533.1"); // 超时设置 /* 从连接池中取连接的超时时间 */ ConnManagerParams.setTimeout(params, 1000); /* 连接超时 */ int ConnectionTimeOut = 3000; if (!HttpUtils.isWifiDataEnable(context)) { ConnectionTimeOut = 10000; } HttpConnectionParams .setConnectionTimeout(params, ConnectionTimeOut); /* 请求超时 */ HttpConnectionParams.setSoTimeout(params, 4000); // 设置我们的HttpClient支持HTTP和HTTPS两种模式 SchemeRegistry schReg = new SchemeRegistry(); schReg.register(new Scheme("http", PlainSocketFactory .getSocketFactory(), 80)); schReg.register(new Scheme("https", SSLSocketFactory .getSocketFactory(), 443)); // 使用线程安全的连接管理来创建HttpClient ClientConnectionManager conMgr = new ThreadSafeClientConnManager( params, schReg); customerHttpClient = new DefaultHttpClient(conMgr, params); } return customerHttpClient; } }