Java tutorial
/* * Chart Service for the GLIMMPSE Software System. Creates * publishable quality scatter plots. * * Copyright (C) 2010 Regents of the University of Colorado. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ package edu.cudenver.bios.chartsvc.resource; import java.awt.BasicStroke; import java.awt.Color; import java.io.IOException; import java.util.ArrayList; import java.util.List; import org.jfree.chart.JFreeChart; import org.jfree.chart.axis.NumberAxis; import org.jfree.chart.block.BlockBorder; import org.jfree.chart.block.ColumnArrangement; import org.jfree.chart.plot.XYPlot; import org.jfree.chart.renderer.xy.XYSplineRenderer; import org.jfree.chart.title.LegendTitle; import org.jfree.data.xy.XYDataset; import org.jfree.data.xy.XYSeries; import org.jfree.data.xy.XYSeriesCollection; import org.jfree.ui.RectangleEdge; import org.restlet.data.Form; import org.restlet.data.Status; import org.restlet.representation.Representation; import org.restlet.representation.Variant; import org.restlet.resource.Get; import org.restlet.resource.ResourceException; import org.restlet.resource.ServerResource; import edu.cudenver.bios.chartsvc.application.ChartLogger; import edu.cudenver.bios.chartsvc.domain.Axis; import edu.cudenver.bios.chartsvc.domain.Chart; import edu.cudenver.bios.chartsvc.domain.LineStyle; import edu.cudenver.bios.chartsvc.domain.Series; import edu.cudenver.bios.chartsvc.representation.ChartImageRepresentation; import edu.cudenver.bios.chartsvc.representation.ErrorXMLRepresentation; /** * Resource which responds to requests for scatter plots * @author Sarah Kreidler * */ public class ScatterPlotResource extends ServerResource { private static final int DEFAULT_WIDTH = 300; private static final int DEFAULT_HEIGHT = 300; private static final String FORM_TAG_CHART = "chart"; private static final String FORM_TAG_SAVE = "save"; private Form queryParams = null; /** * Returns a full representation for a given variant. */ @Get public Representation represent(Variant variant) { queryParams = getRequest().getResourceRef().getQueryAsForm(); ChartImageRepresentation rep = null; try { // parse the chart parameters from the entity body Chart chartSpecification = ChartResourceHelper.chartFromQueryString(queryParams, false); // build a JFreeChart from the specs JFreeChart renderedChart = buildScatterPlot(chartSpecification); // write to an image representation rep = new ChartImageRepresentation(renderedChart, chartSpecification.getWidth(), chartSpecification.getHeight()); // Add file save headers if requested String saveStr = queryParams.getFirstValue(FORM_TAG_SAVE); boolean save = Boolean.parseBoolean(saveStr); if (save) { Form responseHeaders = (Form) getResponse().getAttributes().get("org.restlet.http.headers"); if (responseHeaders == null) { responseHeaders = new Form(); getResponse().getAttributes().put("org.restlet.http.headers", responseHeaders); } responseHeaders.add("Content-type", "application/force-download"); responseHeaders.add("Content-disposition", "attachment; filename=chart.jpg"); } getResponse().setEntity(rep); getResponse().setStatus(Status.SUCCESS_CREATED); } catch (IllegalArgumentException iae) { ChartLogger.getInstance().error(iae.getMessage()); try { getResponse().setEntity(new ErrorXMLRepresentation(iae.getMessage())); } catch (IOException e) { } getResponse().setStatus(Status.CLIENT_ERROR_BAD_REQUEST); } catch (ResourceException re) { ChartLogger.getInstance().error(re.getMessage()); try { getResponse().setEntity(new ErrorXMLRepresentation(re.getMessage())); } catch (IOException e) { } getResponse().setStatus(re.getStatus()); } return rep; } /** * Create a JFreeChart object from the chart specification. JFreechart provides * functionality to render 2D scatter plots as jpeg images * * @param chart chart specification object * @return JFreeChart object * @throws ResourceException */ private JFreeChart buildScatterPlot(Chart chart) throws ResourceException { ArrayList<LineStyle> lineStyleList = chart.getLineStyleList(); float dashedLength = 1.0f; float spaceLength = 1.0f; float thickness = 1.0f; // the first series is treated as the x values if (chart.getSeries() == null || chart.getSeries().size() <= 0) throw new ResourceException(Status.CLIENT_ERROR_BAD_REQUEST, "No data series specified"); // create the jfree chart series XYSeriesCollection chartData = new XYSeriesCollection(); // use a spline renderer to make the connecting lines smooth XYSplineRenderer rend = new XYSplineRenderer(); int seriesIdx = 0; for (Series series : chart.getSeries()) { XYSeries xySeries = new XYSeries(series.getLabel()); List<Double> xList = series.getXCoordinates(); List<Double> yList = series.getYCoordinates(); if (xList != null && yList != null && xList.size() == yList.size()) { for (int i = 0; i < xList.size(); i++) { xySeries.add(xList.get(i), yList.get(i)); } } if (seriesIdx >= 0 && seriesIdx < lineStyleList.size()) { LineStyle lineStyle = lineStyleList.get(seriesIdx); dashedLength = (float) lineStyle.getDashLength(); spaceLength = (float) lineStyle.getSpaceLength(); thickness = (float) lineStyle.getWidth(); } else { dashedLength = 1.0f; spaceLength = 1.0f; thickness = 1.0f; } // set the line style rend.setSeriesPaint(seriesIdx, Color.BLACK); if (seriesIdx >= 0) { /*rend.setSeriesStroke(seriesIdx, new BasicStroke(2.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND, 1.0f, new float[] {(float) seriesIdx, (float) 2*seriesIdx}, 0.0f));*/ rend.setSeriesStroke(seriesIdx, new BasicStroke(thickness, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND, 1.0f, new float[] { dashedLength, spaceLength }, 0.0f)); } // add the series to the data set chartData.addSeries(xySeries); seriesIdx++; } // turn off shapes displayed at each data point to make a smooth curve rend.setBaseShapesVisible(false); // Create the line chart NumberAxis xAxis = new NumberAxis(); xAxis.setAutoRangeIncludesZero(false); if (chart.getXAxis() != null) { Axis xAxisSpec = chart.getXAxis(); xAxis.setLabel(xAxisSpec.getLabel()); if (!Double.isNaN(xAxisSpec.getRangeMin()) && !Double.isNaN(xAxisSpec.getRangeMax())) { xAxis.setRange(xAxisSpec.getRangeMin(), xAxisSpec.getRangeMax()); } } NumberAxis yAxis = new NumberAxis(); if (chart.getYAxis() != null) { Axis yAxisSpec = chart.getYAxis(); yAxis.setLabel(chart.getYAxis().getLabel()); if (!Double.isNaN(yAxisSpec.getRangeMin()) && !Double.isNaN(yAxisSpec.getRangeMax())) { xAxis.setRange(yAxisSpec.getRangeMin(), yAxisSpec.getRangeMax()); } } XYPlot plot = new XYPlot((XYDataset) chartData, xAxis, yAxis, rend); plot.setDomainGridlinesVisible(false); plot.setRangeGridlinesVisible(false); JFreeChart renderedChart = new JFreeChart(chart.getTitle(), JFreeChart.DEFAULT_TITLE_FONT, plot, false); renderedChart.setBackgroundPaint(Color.WHITE); if (chart.hasLegend()) { LegendTitle legend = new LegendTitle(plot, new ColumnArrangement(), new ColumnArrangement()); legend.setFrame(BlockBorder.NONE); legend.setPosition(RectangleEdge.BOTTOM); renderedChart.addLegend(legend); } return renderedChart; } }