Java tutorial
/* * Copyright (C) 2009 Teleca Poland Sp. z o.o. <android@teleca.com> * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.teleca.jamendo.util; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.net.SocketException; import java.net.UnknownHostException; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; import com.teleca.jamendo.MyApplication; import com.teleca.jamendo.model.ErrorMsg; import android.util.Log; /** * @author Lukasz Wisniewski */ public class Caller { /** * Cache for most recent request */ private static RequestCache requestCache = null; /** * Performs HTTP GET using Apache HTTP Client v 4 * * @param url * @return * @throws ErrorMsg */ public static String doGet(String url) throws ErrorMsg { String data = null; if (requestCache != null) { data = requestCache.get(url); if (data != null) { Log.d(MyApplication.TAG, "Caller.doGet [cached] " + url); return data; } } // initialize HTTP GET request objects HttpClient httpClient = new DefaultHttpClient(); HttpGet httpGet = new HttpGet(url); HttpResponse httpResponse; try { // execute request try { httpResponse = httpClient.execute(httpGet); } catch (UnknownHostException e) { ErrorMsg wsError = new ErrorMsg(); wsError.setMessage(e.getLocalizedMessage()); throw wsError; } catch (SocketException e) { ErrorMsg wsError = new ErrorMsg(); wsError.setMessage(e.getLocalizedMessage()); throw wsError; } // request data HttpEntity httpEntity = httpResponse.getEntity(); if (httpEntity != null) { InputStream inputStream = httpEntity.getContent(); data = convertStreamToString(inputStream); // cache the result if (requestCache != null) { requestCache.put(url, data); } } } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } Log.d(MyApplication.TAG, "Caller.doGet " + url); return data; } private static String convertStreamToString(InputStream is) { BufferedReader reader = new BufferedReader(new InputStreamReader(is)); StringBuilder sb = new StringBuilder(); String line = null; try { while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } } catch (IOException e) { e.printStackTrace(); } finally { try { is.close(); } catch (IOException e) { e.printStackTrace(); } } return sb.toString(); } public static void setRequestCache(RequestCache requestCache) { Caller.requestCache = requestCache; } public static String createStringFromIds(int[] ids) { if (ids == null) return ""; String query = ""; for (int id : ids) { query = query + id + "+"; } return query; } }