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.core.client.JsArrayString; 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.PositionData; import com.google.gwt.gdata.client.finance.PositionEntry; import com.google.gwt.gdata.client.finance.PositionFeed; import com.google.gwt.gdata.client.finance.PositionFeedCallback; 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 positions. */ public class FinanceRetrievePositionsDemo 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 FinanceRetrievePositionsDemo(); } @Override public String getDescription() { return "<p>As well as portfolio and transaction feeds, the Google " + "Finance Portfolio Data API offers an intermediate, read-only " + "feed know as the position feed. This is a summary of all of " + "the contents of a particular portfolio, grouped by ticker " + "symbol. Each entry in this feed, know as a position, is " + "derived from the transactions entered for that symbol. Each " + "position entry has position data that may include current " + "number of shares of a particular stock or mutual fund if " + "specified in the transactions as well as investment gain if " + "requested and if purchase price and date have been " + "specified.</p>"; } @Override public String getName() { return "Finance - Retrieving positions"; } }; } 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 FinanceRetrievePositionsDemo() { 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 and its * ID and calls getPositions to retrieve the corresponding * positions feed. * * @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(); if (entries.length == 0) { showStatus("You have no portfolios.", false); } else { PortfolioEntry targetPortfolio = entries[0]; String portfolioId = targetPortfolio.getId().getValue(); JsArrayString match = regExpMatch("\\/(\\d+)$", portfolioId); if (match.length() > 1) { portfolioId = match.get(1); } else { showStatus("Error parsing the portfolio id.", true); } getPositions(portfolioId); } } }); } /** * Retrieve the positions feed for a given portfolio using the * Finance service and the positions feed uri. * The failure handler displays an error message while the * success handler calls showData to display the position entries. * * @param portfolioId The id of the portfolio for which to * retrieve position data */ private void getPositions(String portfolioId) { showStatus("Loading positions feed...", false); String positionsFeedUri = "http://finance.google.com/finance/feeds/default/" + "portfolios/" + portfolioId + "/positions"; service.getPositionFeed(positionsFeedUri, new PositionFeedCallback() { public void onFailure(CallErrorException caught) { showStatus("An error occurred while retrieving the positions feed: " + caught.getMessage(), true); } public void onSuccess(PositionFeed result) { PositionEntry[] entries = result.getEntries(); if (entries.length == 0) { showStatus("No transactions found.", false); } else { showData(entries); } } }); } /** * Expose the JavaScript regular expression parsing to GWT. * * @param regEx The regular expression to use * @param target The text string to parse * @return A JavaScript string array containing any matches */ private native JsArrayString regExpMatch(String regEx, String target) /*-{ var re = new RegExp(); return re.compile(regEx).exec(target); }-*/; /** * Displays a set of Finance position entries in a tabular * fashion with the help of a GWT FlexTable widget. The data fields * Title and Shares are displayed. * * @param entries The Finance position entries to display. */ private void showData(PositionEntry[] entries) { mainPanel.clear(); String[] labels = new String[] { "Title", "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++) { PositionEntry entry = entries[i]; PositionData data = entry.getPositionData(); int row = mainPanel.insertRow(i + 1); mainPanel.addCell(row); mainPanel.setWidget(row, 0, new Label(entry.getTitle().getText())); mainPanel.addCell(row); mainPanel.setWidget(row, 1, 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_RetrievePositionsDemo_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); } } }