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.gdata.client.GData; import com.google.gwt.gdata.client.GDataSystemPackage; import com.google.gwt.gdata.client.finance.FinanceService; import com.google.gwt.gdata.client.finance.PortfolioEntry; import com.google.gwt.gdata.client.finance.PortfolioFeed; import com.google.gwt.gdata.client.finance.PortfolioFeedCallback; import com.google.gwt.gdata.client.finance.TransactionData; import com.google.gwt.gdata.client.finance.TransactionEntry; import com.google.gwt.gdata.client.finance.TransactionFeed; import com.google.gwt.gdata.client.finance.TransactionFeedCallback; import com.google.gwt.gdata.client.impl.CallErrorException; import com.google.gwt.user.client.ui.FlexTable; import com.google.gwt.user.client.ui.Label; /** * The following example demonstrates how to retrieve a list of transactions. */ public class FinanceRetrieveTransactionsDemo 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 FinanceRetrieveTransactionsDemo(); } @Override public String getDescription() { return "<p>In this sample, all transactions for a particular " + "ticker (e.g. NYSE:IBM) are retrieved for a portfolio. The " + "user's portfolio feed is queried and searched for a portfolio " + "starting with 'GWT-Finance-Client'. The transaction feed for " + "NASDAQ:GOOG is then queried for this portfolio and basic " + "information is displayed. (This portfolio and transaction " + "were created in the examples above -- if no transactions for " + "a given ticker exist, the transaction feed will not exist and " + "an error will be generated).</p>"; } @Override public String getName() { return "Finance - Retrieving transactions"; } }; } 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 FinanceRetrieveTransactionsDemo() { 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 retrieves all transactions * with the ticker symbol "NASDAQ:GOOG". * If no transactions exist with this symbol, the request will fail. * 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 { String ticker = "NASDAQ:GOOG"; String transactionFeedUri = targetPortfolio.getEditLink().getHref() + "/positions/" + ticker + "/transactions"; getTransactions(transactionFeedUri); } } }); } /** * Retrieve the transactions feed for a given portfolio using the * Finance service and the transactions feed uri. * The failure handler displays an error message while the * success handler calls showData to display the transaction entries. * * @param transactionFeedUri The transaction feed uri */ private void getTransactions(String transactionFeedUri) { showStatus("Loading transactions feed...", false); service.getTransactionFeed(transactionFeedUri, new TransactionFeedCallback() { public void onFailure(CallErrorException caught) { showStatus("An error occurred while retrieving the portfolios " + "feed: " + caught.getMessage(), true); } public void onSuccess(TransactionFeed result) { TransactionEntry[] entries = result.getEntries(); if (entries.length == 0) { showStatus("No transactions found.", false); } else { showData(entries); } } }); } /** * Displays a set of Finance transaction entries in a tabular * fashion with the help of a GWT FlexTable widget. The data fields * Notes, Type and Shares are displayed. * * @param entries The Finance transaction entries to display. */ private void showData(TransactionEntry[] entries) { mainPanel.clear(); String[] labels = new String[] { "Notes", "Type", "Shares" }; mainPanel.insertRow(0); for (int i = 0; i < labels.length; i++) { mainPanel.addCell(0); mainPanel.setWidget(0, i, new Label(labels[i])); mainPanel.getFlexCellFormatter().setStyleName(0, i, "hm-tableheader"); } for (int i = 0; i < entries.length; i++) { TransactionEntry entry = entries[i]; TransactionData data = entry.getTransactionData(); int row = mainPanel.insertRow(i + 1); mainPanel.addCell(row); mainPanel.setWidget(row, 0, new Label(data.getNotes())); mainPanel.addCell(row); mainPanel.setWidget(row, 1, new Label(data.getType())); mainPanel.addCell(row); mainPanel.setWidget(row, 2, new Label("" + data.getShares())); } } /** * 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_RetrieveTransactionsDemo_v2.0"); if (User.getStatus(scope) == AuthSubStatus.LOGGED_IN) { getPortfolios("http://finance.google.com/finance/feeds/default/portfolios"); } else { showStatus("You are not logged on to Google Finance.", true); } } }