Java tutorial
/** * The contents of this file are subject to the OpenMRS Public License * Version 1.0 (the "License"); you may not use this file except in * compliance with the License. You may obtain a copy of the License at * http://license.openmrs.org * * Software distributed under the License is distributed on an "AS IS" * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the * License for the specific language governing rights and limitations * under the License. * * Copyright (C) OpenMRS, LLC. All Rights Reserved. */ package org.openmrs.module.tracpatienttransfer.web.view.chart; import java.awt.BasicStroke; import java.awt.Color; import java.awt.Font; import java.util.Map; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.jfree.chart.ChartUtilities; import org.jfree.chart.JFreeChart; import org.openmrs.module.tracpatienttransfer.util.TransferOutInPatientUtil; import org.springframework.web.servlet.view.AbstractView; /** * Base class for views that render usage data as a comma separated values */ public abstract class AbstractChartView extends AbstractView { protected static final Log log = LogFactory.getLog(AbstractChartView.class); private static Font font = new Font("Verdana", Font.PLAIN, 10); private static Color bkColor = new Color(240, 240, 250); /** * @see org.springframework.web.servlet.view.AbstractView */ @Override @SuppressWarnings("unchecked") protected void renderMergedOutputModel(Map model, HttpServletRequest request, HttpServletResponse response) throws Exception { // Respond as a PNG image response.setContentType("image/png"); // Disable caching response.setHeader("Pragma", "No-cache"); response.setDateHeader("Expires", 0); response.setHeader("Cache-Control", "no-cache"); int width = Integer.valueOf(request.getParameter("width")); int height = Integer.valueOf(request.getParameter("height")); ; JFreeChart chart = createChart(model, request); chart.setBackgroundPaint(Color.WHITE); chart.getPlot().setOutlineStroke(new BasicStroke(0)); chart.getPlot().setOutlinePaint(getBackgroundColor()); chart.getPlot().setBackgroundPaint(getBackgroundColor()); chart.getPlot().setNoDataMessage( TransferOutInPatientUtil.getMessage("tracpatienttransfer.error.noDataAvailable", null)); ChartUtilities.writeChartAsPNG(response.getOutputStream(), chart, width, height); } /** * Generates a JFreeChart * * @param model * the model * @param request * the servlet request * @return the chart object */ protected abstract JFreeChart createChart(Map<String, Object> model, HttpServletRequest request); /** * Gets the font for chart rendering */ protected Font getFont() { return font; } /** * Gets the plot background color */ protected Color getBackgroundColor() { return bkColor; } }