Java tutorial
/* * Copyright 2008 Google Inc. * * 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.google.gwt.gdata.sample.hellogdata.client; import com.google.gwt.accounts.client.AuthSubStatus; import com.google.gwt.accounts.client.User; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.event.dom.client.ClickHandler; import com.google.gwt.gdata.client.GData; import com.google.gwt.gdata.client.GDataSystemPackage; import com.google.gwt.gdata.client.atom.Text; import com.google.gwt.gdata.client.finance.FinanceService; import com.google.gwt.gdata.client.finance.PortfolioEntry; import com.google.gwt.gdata.client.finance.PortfolioEntryCallback; import com.google.gwt.gdata.client.finance.PortfolioFeed; import com.google.gwt.gdata.client.finance.PortfolioFeedCallback; import com.google.gwt.gdata.client.impl.CallErrorException; import com.google.gwt.user.client.ui.Button; import com.google.gwt.user.client.ui.FlexTable; import com.google.gwt.user.client.ui.Label; /** * The following example demonstrates how to update a portfolio. */ public class FinanceUpdatePortfolioDemo extends GDataDemo { /** * This method is used by the main sample app to obtain * information on this sample and a sample instance. * * @return An instance of this demo. */ public static GDataDemoInfo init() { return new GDataDemoInfo() { @Override public GDataDemo createInstance() { return new FinanceUpdatePortfolioDemo(); } @Override public String getDescription() { return "<p>This sample demonstrates how to update an existing " + "portfolio for the authenticated user. It retrieves a list of " + "the user's portfolios, and updates the first portfolio with a " + "title that starts with 'GWT-Finance-Client' with a new " + "title.</p>"; } @Override public String getName() { return "Finance - Updating a portfolio"; } }; } private FinanceService service; private FlexTable mainPanel; private final String scope = "http://finance.google.com/finance/feeds/"; /** * Setup the Finance service and create the main content panel. * If the user is not logged on to Finance display a message, * otherwise start the demo by retrieving the user's portfolios. */ public FinanceUpdatePortfolioDemo() { mainPanel = new FlexTable(); initWidget(mainPanel); if (!GData.isLoaded(GDataSystemPackage.FINANCE)) { showStatus("Loading the GData Finance package...", false); GData.loadGDataApi(GDATA_API_KEY, new Runnable() { public void run() { startDemo(); } }, GDataSystemPackage.FINANCE); } else { startDemo(); } } /** * Retrieve the portfolios feed using the Finance service and * the portfolios feed uri. In GData all get, insert, update * and delete methods always receive a callback defining * success and failure handlers. * Here, the failure handler displays an error message while the * success handler obtains the first portfolio entry with a title * starting with "GWT-Finance-Client" and calls updatePortfolio to * update the portfolio. * If no portfolio is found, a message is displayed. * * @param portfoliosFeedUri The uri of the portfolios feed */ private void getPortfolios(String portfoliosFeedUri) { showStatus("Loading portfolios feed...", false); service.getPortfolioFeed(portfoliosFeedUri, new PortfolioFeedCallback() { public void onFailure(CallErrorException caught) { showStatus("An error occurred while retrieving the portfolios feed: " + caught.getMessage(), true); } public void onSuccess(PortfolioFeed result) { PortfolioEntry[] entries = result.getEntries(); PortfolioEntry targetPortfolio = null; for (PortfolioEntry entry : entries) { if (entry.getTitle().getText().startsWith("GWT-Finance-Client")) { targetPortfolio = entry; break; } } if (targetPortfolio == null) { showStatus("No portfolio found that contains 'GWT-Finance-Client' " + "in the title.", false); } else { updatePortfolio(targetPortfolio); } } }); } /** * Displays a status message to the user. * * @param message The message to display. * @param isError Indicates whether the status is an error status. */ private void showStatus(String message, boolean isError) { mainPanel.clear(); mainPanel.insertRow(0); mainPanel.addCell(0); Label msg = new Label(message); if (isError) { msg.setStylePrimaryName("hm-error"); } mainPanel.setWidget(0, 0, msg); } /** * Starts this demo. */ private void startDemo() { service = FinanceService.newInstance("HelloGData_Finance_UpdatePortfolioDemo_v2.0"); if (User.getStatus(scope) == AuthSubStatus.LOGGED_IN) { Button startButton = new Button("Update a portfolio"); startButton.addClickHandler(new ClickHandler() { public void onClick(ClickEvent event) { getPortfolios("http://finance.google.com/finance/feeds/default/portfolios"); } }); mainPanel.setWidget(0, 0, startButton); } else { showStatus("You are not logged on to Google Finance.", true); } } /** * Update a portfolio by making use of the updateEntry * method of the Entry class. * Set the portfolio title to an arbitrary string. Here * we prefix the title with 'GWT-Finance-Client' so that * we can identify which portfolios were updated by this demo. * On success and failure, display a status message. * * @param targetPortfolio The portfolio entry which to update */ private void updatePortfolio(PortfolioEntry targetPortfolio) { showStatus("Updating portfolio...", false); targetPortfolio.setTitle(Text.newInstance()); targetPortfolio.getTitle().setText("GWT-Finance-Client - updated portfolio"); targetPortfolio.updateEntry(new PortfolioEntryCallback() { public void onFailure(CallErrorException caught) { showStatus("An error occurred while updating a portfolio: " + caught.getMessage(), true); } public void onSuccess(PortfolioEntry result) { showStatus("Updated a portfolio.", false); } }); } }