【移動GIS】android中訪問HTTP介面

移動GIS中，訪問INTERNET是不可或缺的，無論是線上地圖還是離線的，都得用到，再次，整理了一個HttpConnection通用類，省的每次用的時候都copy了

import java.io.IOException;import java.io.InputStream;import java.util.List;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.NameValuePair;import org.apache.http.StatusLine;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.params.BasicHttpParams;import org.apache.http.params.HttpConnectionParams;import org.apache.http.params.HttpParams;import org.apache.http.util.EntityUtils;import android.util.Log;public class HttpConnection {private DefaultHttpClient client;private InputStream stream;private HttpEntity entity;private String mUserAgent;private final static int TIMEOUT_CONNECTION=3000; //ms private final static int TIMEOUT_SOCKET=8000; //ms/** Constructor.  * Opens the url with an HttpURLConnection, then opens a stream on it.  * @param String sUrl: url to open */public HttpConnection(){stream = null;entity = null;HttpParams httpParameters = new BasicHttpParams();/* useful?HttpProtocolParams.setContentCharset(httpParameters, "UTF-8"); HttpProtocolParams.setHttpElementCharset(httpParameters, "UTF-8");*/// Set the timeout in milliseconds until a connection is established.HttpConnectionParams.setConnectionTimeout(httpParameters, TIMEOUT_CONNECTION);// Set the default socket timeout (SO_TIMEOUT) // in milliseconds which is the timeout for waiting for data.HttpConnectionParams.setSoTimeout(httpParameters, TIMEOUT_SOCKET);client = new DefaultHttpClient(httpParameters); //TODO: created here. Reuse to do for better perfs???...}public void setUserAgent(String userAgent){mUserAgent = userAgent;}public void doGet(String sUrl){HttpGet request = new HttpGet(sUrl);if (mUserAgent != null)request.setHeader("User-Agent", mUserAgent);try {HttpResponse response = client.execute(request);StatusLine status = response.getStatusLine();if (status.getStatusCode() != 200) {Log.e(BonusPackHelper.LOG_TAG, "Invalid response from server: " + status.toString());} else {entity = response.getEntity();}} catch (IOException e){e.printStackTrace();}}public void doPost(String sUrl, List<NameValuePair> nameValuePairs) {HttpPost request = new HttpPost(sUrl);if (mUserAgent != null)request.setHeader("User-Agent", mUserAgent);try {request.setEntity(new UrlEncodedFormEntity(nameValuePairs));HttpResponse response = client.execute(request);StatusLine status = response.getStatusLine();if (status.getStatusCode() != 200) {Log.e(BonusPackHelper.LOG_TAG, "Invalid response from server: " + status.toString());} else {entity = response.getEntity();}} catch (ClientProtocolException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}/**  * @return the opened InputStream, or null if creation failed for any reason.  */public InputStream getStream() {try {if (entity != null)stream = entity.getContent();} catch (IOException e) {e.printStackTrace();}return stream;}/** * @return the whole content as a String, or null if creation failed for any reason.  */public String getContentAsString(){try {if (entity != null) {return EntityUtils.toString(entity, "UTF-8");//setting the charset is important if none found in the entity. } else return null;} catch (IOException e) {e.printStackTrace();return null;}}/** * Calling close once is mandatory.  */public void close(){if (stream != null){try { stream.close();stream = null;} catch (IOException e) {e.printStackTrace();}}if (entity != null){try {entity.consumeContent(); //"finish". Important if we want to reuse the client object one day... entity = null;} catch (IOException e) {e.printStackTrace();}}if (client != null){client.getConnectionManager().shutdown();client = null;}}}：

  該怎麼用呢？很簡單了，舉個例子吧

HttpConnection connection = new HttpConnection();  connection.doGet("http://www.google.com");  InputStream stream = connection.getStream();  if (stream != null) {  //得到流之後, 就可以處理了，比如XML解析等。。。  }