Java tutorial
/** * Copyright (c) 2000-present Liferay, Inc. All rights reserved. * * This library is free software; you can redistribute it and/or modify it under * the terms of the GNU Lesser General Public License as published by the Free * Software Foundation; either version 2.1 of the License, or (at your option) * any later version. * * This library 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 Lesser General Public License for more * details. */ package com.liferay.samplestruts.struts.action; import com.liferay.portal.kernel.log.Log; import com.liferay.portal.kernel.log.LogFactoryUtil; import java.io.OutputStream; import java.util.Enumeration; import javax.portlet.PortletSessionUtil; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import javax.servlet.jsp.PageContext; import org.apache.struts.action.Action; import org.apache.struts.action.ActionForm; import org.apache.struts.action.ActionForward; import org.apache.struts.action.ActionMapping; import org.jfree.chart.ChartFactory; import org.jfree.chart.ChartUtilities; import org.jfree.chart.JFreeChart; import org.jfree.chart.plot.PlotOrientation; import org.jfree.data.category.CategoryDataset; import org.jfree.data.category.DefaultCategoryDataset; import org.jfree.data.general.DatasetUtilities; import org.jfree.data.general.PieDataset; /** * @author Brian Wing Shun Chan */ public class ViewChartAction extends Action { @Override public ActionForward execute(ActionMapping actionMapping, ActionForm actionForm, HttpServletRequest request, HttpServletResponse response) throws Exception { try { if (_log.isInfoEnabled()) { _log.info("execute"); } String attrName = "chart_name"; // Application scoped session attributes can be fetched from the // servlet directly. Portlet scoped session attributes can be // fetched from Sun's PortletSessionUtil. HttpSession session = request.getSession(); String chartName = (String) session.getAttribute(attrName); //(String)_getAttribute(request, attrName); // Chart String chartType = request.getParameter("chart_type"); CategoryDataset dataset = _getDataset(); String xName = "Soda"; String yName = "Votes"; JFreeChart chart = null; if (chartType.equals("area")) { chart = ChartFactory.createAreaChart(chartName, xName, yName, dataset, PlotOrientation.VERTICAL, true, false, false); } else if (chartType.equals("horizontal_bar")) { chart = ChartFactory.createBarChart(chartName, xName, yName, dataset, PlotOrientation.HORIZONTAL, true, false, false); } else if (chartType.equals("line")) { chart = ChartFactory.createLineChart(chartName, xName, yName, dataset, PlotOrientation.VERTICAL, true, false, false); } else if (chartType.equals("vertical_bar")) { chart = ChartFactory.createBarChart(chartName, xName, yName, dataset, PlotOrientation.VERTICAL, true, false, false); } else { PieDataset pieData = DatasetUtilities.createPieDatasetForRow(dataset, 0); chart = ChartFactory.createPieChart(chartName, pieData, true, false, false); } response.setContentType("image/jpeg"); OutputStream out = response.getOutputStream(); ChartUtilities.writeChartAsJPEG(out, chart, 400, 400); return actionMapping.findForward("/common/null.jsp"); } catch (Exception e) { request.setAttribute(PageContext.EXCEPTION, e); return actionMapping.findForward("/common/error.jsp"); } } private Object _getAttribute(HttpServletRequest request, String attrName) { // Go through all the session attributes and use Sun's // PortletSessionUtil to match the correct attribute name HttpSession session = request.getSession(); Enumeration<String> enu = session.getAttributeNames(); while (enu.hasMoreElements()) { String encodedAttrName = enu.nextElement(); String decodedAttrName = PortletSessionUtil.decodeAttributeName(encodedAttrName); if (decodedAttrName.equals(attrName)) { return session.getAttribute(encodedAttrName); } } return null; } private CategoryDataset _getDataset() throws Exception { DefaultCategoryDataset dataset = new DefaultCategoryDataset(); String seriesName = ""; dataset.addValue(Integer.valueOf(9), seriesName, "Coke"); dataset.addValue(Integer.valueOf(21), seriesName, "Pepsi"); return dataset; } private static Log _log = LogFactoryUtil.getLog(ViewChartAction.class); }