Java tutorial
package de.kp.ames.web.client.core.http; /** * This Java module is part of the * Application Developer Framework * * Project: AMES-Web-GUI * Package: de.kp.ames.web.client.core.http * Module: ConnectionManager * @author krusche@dr-kruscheundpartner.de * * Add your semantic annotations within the SemanticAssist tags and * mark them with a leading hashtag #: * * <SemanticAssist> * #client #connection #core #http #manager #web * </SemanticAssist> * */ /** * Copyright 2012 Dr. Krusche & Partner PartG * * AMES-Web-GUI is free software: you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, either version 3 of * the License, or (at your option) any later version. * * AMES- Web-GUI is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * * See the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this software. If not, see <http://www.gnu.org/licenses/>. * */ import java.util.HashMap; import java.util.Set; import com.google.gwt.http.client.Request; import com.google.gwt.http.client.RequestBuilder; import com.google.gwt.http.client.RequestCallback; import com.google.gwt.http.client.RequestException; import com.google.gwt.http.client.RequestTimeoutException; import com.google.gwt.http.client.Response; import com.google.gwt.http.client.URL; import de.kp.ames.web.client.core.globals.GuiConstants; import de.kp.ames.web.client.core.method.RequestMethodImpl; /** * @author Stefan Krusche (krusche@dr-kruscheundpartner.de) * */ public class ConnectionManager { private static final int STATUS_CODE_OK = 200; private static ConnectionManager instance = new ConnectionManager(); public static ConnectionManager getInstance() { if (instance == null) instance = new ConnectionManager(); return instance; } /** * @param baseUrl * @param method * @param callback */ public void sendGetRequest(final String baseUrl, final RequestMethodImpl method, final HashMap<String, String> headers, final ConnectionCallback callback) { String url = baseUrl + method.toQuery(); sendGetRequest(url, headers, callback); } /** * @param url * @param callback */ public void sendGetRequest(final String url, final HashMap<String, String> headers, final ConnectionCallback callback) { RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, URL.encode(url)); builder.setTimeoutMillis(GuiConstants.CONNECTION_TIMEOUT); /* * Set header parameters */ if (headers.isEmpty() == false) { Set<String> keys = headers.keySet(); for (String key : keys) { builder.setHeader(key, headers.get(key)); } } /* * Set request callback */ builder.setCallback(new RequestCallback() { public void onResponseReceived(Request request, Response response) { if (STATUS_CODE_OK == response.getStatusCode()) { handleSuccess(response, callback); } else { handleFailure(response, callback); } } public void onError(Request request, Throwable exception) { if (exception instanceof RequestTimeoutException) { handleTimeout(exception, callback); } else { handleError(exception, callback); } } }); try { builder.send(); } catch (RequestException e) { handleError(e, callback); } } /** * @param baseUrl * @param method * @param requestData * @param callback */ public void sendPostRequest(final String baseUrl, final RequestMethodImpl method, final HashMap<String, String> headers, final String requestData, final ConnectionCallback callback) { String url = baseUrl + method.toQuery(); sendPostRequest(url, headers, requestData, callback); } /** * @param url * @param requestData * @param callback */ public void sendPostRequest(final String url, final HashMap<String, String> headers, final String requestData, final ConnectionCallback callback) { RequestBuilder builder = new RequestBuilder(RequestBuilder.POST, URL.encode(url)); builder.setTimeoutMillis(GuiConstants.CONNECTION_TIMEOUT); /* * Set header parameters */ if (headers.isEmpty() == false) { Set<String> keys = headers.keySet(); for (String key : keys) { builder.setHeader(key, headers.get(key)); } } /* * Set request data */ if (requestData != null) builder.setRequestData(requestData); /* * Set request callback */ builder.setCallback(new RequestCallback() { public void onResponseReceived(Request request, Response response) { if (STATUS_CODE_OK == response.getStatusCode()) { handleSuccess(response, callback); } else { handleFailure(response, callback); } } public void onError(Request request, Throwable exception) { if (exception instanceof RequestTimeoutException) { handleTimeout(exception, callback); } else { handleError(exception, callback); } } }); try { builder.send(); } catch (RequestException e) { handleError(e, callback); } } /** * @param response * @param callback */ private void handleSuccess(Response response, ConnectionCallback callback) { String responseText = response.getText(); if (callback != null) callback.onSuccess(responseText); } /** * @param response * @param callback */ private void handleFailure(Response response, ConnectionCallback callback) { String responseText = response.getText(); if (callback != null) callback.onFailure(responseText); } /** * @param throwable * @param callback */ private void handleError(Throwable throwable, ConnectionCallback callback) { if (callback != null) callback.onError(throwable); } /** * @param exception * @param callback */ private void handleError(RequestException exception, ConnectionCallback callback) { if (callback != null) callback.onError(exception); } /** * @param throwable * @param callback */ private void handleTimeout(Throwable throwable, ConnectionCallback callback) { RequestTimeoutException exception = (RequestTimeoutException) throwable; if (callback != null) callback.onTimeout(exception.getMessage()); } }