Java tutorial
/******************************************************************************* * Copyright (c) 2014 Alexandr Tsvetkov. * All rights reserved. This program and the accompanying materials * are made available under the terms of the GNU Lesser General Public License * which accompanies this distribution, and is available at * http://www.gnu.org/licenses/lgpl.html * * Contributors: * Alexandr Tsvetkov - initial API and implementation * * Project: * TAO Data Processor * * License agreement: * * 1. This code is published AS IS. Author is not responsible for any damage that can be * caused by any application that uses this code. * 2. Author does not give a garantee, that this code is error free. * 3. This code can be used in NON-COMMERCIAL applications AS IS without any special * permission from author. * 4. This code can be modified without any special permission from author IF AND ONLY IF * this license agreement will remain unchanged. ******************************************************************************/ package ua.at.tsvetkov.data_processor; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.lang.reflect.Constructor; import java.security.InvalidParameterException; import org.apache.http.HttpStatus; import ua.at.tsvetkov.data_processor.interfaces.InputStreamDataInterface; import ua.at.tsvetkov.data_processor.interfaces.StringDataInterface; import ua.at.tsvetkov.data_processor.processors.InputStreamProcessor; import ua.at.tsvetkov.data_processor.processors.StringProcessor; import ua.at.tsvetkov.data_processor.processors.abstractclasses.AbstractProcessor; import ua.at.tsvetkov.data_processor.requests.Request; import ua.at.tsvetkov.util.Const; import ua.at.tsvetkov.util.Log; import android.os.Handler; import android.os.Looper; public class ProcessingCentre<T> { private static final String INVALID_CLASS_PARAMETER = "Invalid class parameter. A class for data processing must implement InputStreamDataInterface or StringDataInterface either extend AbstractProcessor"; private static final String INVALID_PARAMETER = "Invalid parameter. Request or Class can't be eq null"; public static final int BUFFER = 8 * Const.KB; /** * File was opened success. */ public static final int FILE_SUCCESS = 0; /** * Processing ERROR code. */ public static final int ERROR = -1; private Request request; private AbstractProcessor<T> processor; private InputStream inputStream; private String cacheFileName; private Class<T> clazz; private Callback<T> callback; private Thread thread; private final Handler handler; /** * @param request * @param clazz */ public ProcessingCentre(Request request, Class<T> clazz) { if (request == null || clazz == null) { throw new InvalidParameterException(INVALID_PARAMETER); } this.request = request; this.clazz = clazz; this.callback = null; if (Looper.myLooper() != null) handler = new Handler(); else handler = null; thread = Thread.currentThread(); } /** * @param request * @param clazz * @param callback */ public ProcessingCentre(Request request, Class<T> clazz, Callback<T> callback) { if (request == null || clazz == null) { throw new InvalidParameterException(INVALID_PARAMETER); } this.request = request; this.clazz = clazz; this.callback = callback; if (Looper.myLooper() != null) handler = new Handler(); else handler = null; thread = Thread.currentThread(); } public T execute() { if (!isCorrectClass()) { throw new InvalidParameterException(INVALID_CLASS_PARAMETER); } cacheFileName = request.getCacheFileName(); try { if (cacheFileName != null && cacheFileName.length() > 0) { saveToFile(); } else { inputStream = request.getInputStream(); } if (request.getStatusCode() == FILE_SUCCESS || request.getStatusCode() == HttpStatus.SC_OK) { createProcessor(); } if (processor != null) { processor.parse(inputStream); sendMessage(request.getStatusCode(), (T) processor.getResult()); } else { sendMessage(request.getStatusCode(), null); // sendMessage(request.getStatusCode(), inputStream); WTF??? } } catch (Exception e) { Log.e(e); sendMessage(ERROR, null); } finally { try { if (inputStream != null) inputStream.close(); request.close(); } catch (Exception e) { Log.e(e); } } if (DataProcessor.getInstance().getConfiguration().isLogEnabled() && DataProcessor.getInstance().getConfiguration().isShowProcessingTime()) { long time = System.currentTimeMillis() - request.getStartTime(); Log.v("Processing time = " + time + " ms. [ " + request + " ]"); } if (processor != null) return (T) processor.getResult(); else return null; } /** * */ @SuppressWarnings({ "rawtypes", "unchecked" }) private void createProcessor() { try { if (AbstractProcessor.class.isAssignableFrom(clazz)) { Constructor[] construct = clazz.getDeclaredConstructors(); processor = (AbstractProcessor) construct[0].newInstance(); } else if (InputStreamDataInterface.class.isAssignableFrom(clazz)) { Constructor[] construct = clazz.getDeclaredConstructors(); processor = new InputStreamProcessor((InputStreamDataInterface) construct[0].newInstance()); } else if (StringDataInterface.class.isAssignableFrom(clazz)) { Constructor[] construct = clazz.getDeclaredConstructors(); processor = new StringProcessor((StringDataInterface) construct[0].newInstance()); } else Log.e(INVALID_CLASS_PARAMETER); } catch (Exception e) { Log.e("Can't create " + clazz.getCanonicalName(), e); } } /** * @return */ private boolean isCorrectClass() { if (InputStreamDataInterface.class.isAssignableFrom(clazz)) { return true; } else if (StringDataInterface.class.isAssignableFrom(clazz)) { return true; } else if (AbstractProcessor.class.isAssignableFrom(clazz)) { return true; } else return false; } private void sendMessage(final int statusCode, final T object) { if (callback != null) { if (thread == Thread.currentThread()) { callback.onFinish(object, statusCode); } else { handler.post(new Runnable() { @Override public void run() { callback.onFinish(object, statusCode); } }); } } } public void executeAsync() { new Thread(new Runnable() { @Override public void run() { execute(); } }, "Processing center execute async request").start(); } private void saveToFile() throws IOException { File f = new File(cacheFileName); if (!request.isNeedToRewriteFile() && f.exists() && f.length() > 0) { if (DataProcessor.getInstance().getConfiguration().isLogEnabled()) { Log.w("File exist: " + cacheFileName); } return; } FileOutputStream out = new FileOutputStream(cacheFileName); byte[] buffer = new byte[BUFFER]; int bytesRead = -1; inputStream = request.getInputStream(); while ((bytesRead = inputStream.read(buffer)) != -1) { out.write(buffer, 0, bytesRead); } out.flush(); out.close(); inputStream.close(); inputStream = new FileInputStream(cacheFileName); } public static interface Callback<T> { /** * Runs on the UI thread. * * @param obj * @param what */ public abstract void onFinish(T obj, int what); } }