From 137da15d07cbaac9618f59af10fdf19819985ba8 Mon Sep 17 00:00:00 2001 From: Philip Luppens Date: Sat, 8 Sep 2007 21:48:46 +0000 Subject: [PATCH] Made some minimal changes to improve the JFreeChart Result: - chart getter can be specified - type (png/jpg) can be specified - throws NPEs if required fields are missing - added example configuration and Action git-svn-id: https://svn.apache.org/repos/asf/struts/struts2/trunk@573912 13f79535-47bb-0310-9956-ffa450edef68 --- .../struts2/dispatcher/ChartResult.java | 185 +++++++++++++----- 1 file changed, 131 insertions(+), 54 deletions(-) diff --git a/plugins/jfreechart/src/main/java/org/apache/struts2/dispatcher/ChartResult.java b/plugins/jfreechart/src/main/java/org/apache/struts2/dispatcher/ChartResult.java index 129c7a5a2..e273104ae 100644 --- a/plugins/jfreechart/src/main/java/org/apache/struts2/dispatcher/ChartResult.java +++ b/plugins/jfreechart/src/main/java/org/apache/struts2/dispatcher/ChartResult.java @@ -26,88 +26,165 @@ import com.opensymphony.xwork2.Result; import org.jfree.chart.ChartUtilities; import org.jfree.chart.JFreeChart; -import javax.servlet.http.HttpServletResponse; import java.io.OutputStream; - /** + * + *

* A custom Result type for chart data. Built on top of * JFreeChart. When executed - * this Result will write the given chart as a PNG to the servlet output stream. + * this Result will write the given chart as a PNG or JPG to the servlet output stream. + *

+ * + *

+ * This result type takes the following parameters: + *

+ * + *

+ *

+ * + *

+ * Example: + *

+ * 


+ * public class ExampleChartAction extends ActionSupport {
  *
+ *	    private JFreeChart chart;
+ *
+ *	    public String execute() throws Exception {
+ *		    // chart creation logic...
+ *		    XYSeries dataSeries = new XYSeries(new Integer(1)); // pass a key for this serie
+ *		    for (int i = 0; i <= 100; i++) {
+ *			    dataSeries.add(i, RandomUtils.nextInt());
+ *		    }
+ *		    XYSeriesCollection xyDataset = new XYSeriesCollection(dataSeries);
+ *
+ *		    ValueAxis xAxis = new NumberAxis("Raw Marks");
+ *		    ValueAxis yAxis = new NumberAxis("Moderated Marks");
+ *
+ *		    // set my chart variable
+ *		    chart =
+ *			    new JFreeChart( "Moderation Function", JFreeChart.DEFAULT_TITLE_FONT,
+ *				    new XYPlot( xyDataset, xAxis, yAxis, new StandardXYItemRenderer(StandardXYItemRenderer.LINES)),
+ *				    false);
+ *		    chart.setBackgroundPaint(java.awt.Color.white);
+ *
+ *		    return SUCCESS;
+ *	    }
+ * 
+ *      // this method will get called if we specify <param name="value">chart</param>
+ *	    public JFreeChart getChart() {
+ *		    return chart;
+ *	    }
+ *  }
+ *
+ * <result name="success" type="chart">
+ *   <param name="value">chart</param>
+ *   <param name="type">png</param>
+ *   <param name="width">640</param>
+ *   <param name="height">480</param>
+ * </result>
+ *
*/ public class ChartResult implements Result { private static final long serialVersionUID = -6484761870055986612L; + private static final String DEFAULT_TYPE = "png"; + private static final String DEFAULT_VALUE = "chart"; - JFreeChart chart; - boolean chartSet = false; - private int height; - private int width; + private JFreeChart chart; // the JFreeChart to render + Integer height, width; + String type = DEFAULT_TYPE; // supported are jpg, jpeg or png, defaults to png + String value = DEFAULT_VALUE; // defaults to 'chart' + + // CONSTRUCTORS ---------------------------- public ChartResult() { super(); } public ChartResult(JFreeChart chart, int height, int width) { - setChart(chart); - this.height = height; - this.width = width; - } - - /** - * Sets the JFreeChart to use. - * - * @param chart a JFreeChart object. - */ - public ChartResult setChart(JFreeChart chart) { this.chart = chart; - chartSet = true; - return this; - } - - /** - * Sets the chart height. - * - * @param height the height of the chart in pixels. - */ - public ChartResult setHeight(int height) { this.height = height; - return this; - } - - /** - * Sets the chart width. - * - * @param width the width of the chart in pixels. - */ - public ChartResult setWidth(int width) { this.width = width; - return this; } + // ACCESSORS ---------------------------- + + public Integer getHeight() { + return height; + } + + public void setHeight(Integer height) { + this.height = height; + } + + public Integer getWidth() { + return width; + } + + public void setWidth(Integer width) { + this.width = width; + } + + public String getType() { + return type; + } + + public void setType(String type) { + this.type = type; + } + + public String getValue() { + return value; + } + + public void setValue(String value) { + this.value = value; + } + + // OTHER METHODS ----------------------- + + // Required by com.opensymphony.xwork2.Result + /** - * Executes the result. Writes the given chart as a PNG to the servlet output stream. + * Executes the result. Writes the given chart as a PNG or JPG to the servlet output stream. * * @param invocation an encapsulation of the action execution state. * @throws Exception if an error occurs when creating or writing the chart to the servlet output stream. */ public void execute(ActionInvocation invocation) throws Exception { - JFreeChart chart = null; + chart = (JFreeChart) invocation.getStack().findValue(value, JFreeChart.class); + if (chart == null) // we need to have a chart object - if not, blow up + throw new NullPointerException("No JFreeChart object found on the stack with name " + value); + // make sure we have some value for the width and height + if (height == null) + throw new NullPointerException("No height parameter was given."); + if (width == null) + throw new NullPointerException("No width parameter was given."); - if (chartSet) { - chart = this.chart; - } else { - chart = (JFreeChart) invocation.getStack().findValue("chart"); + // get a reference to the servlet output stream to write our chart image to + OutputStream os = ServletActionContext.getResponse().getOutputStream(); + try { + // check the type to see what kind of output we have to produce + if ("png".equalsIgnoreCase(type)) + ChartUtilities.writeChartAsPNG(os, chart, width, height); + else if ("jpg".equalsIgnoreCase(type) || "jpeg".equalsIgnoreCase(type)) + ChartUtilities.writeChartAsJPEG(os, chart, width, height); + else + throw new IllegalArgumentException(type + " is not a supported render type (only JPG and PNG are)."); + } finally { + if (os != null) os.flush(); } - - if (chart == null) { - throw new NullPointerException("No chart found"); - } - - HttpServletResponse response = ServletActionContext.getResponse(); - OutputStream os = response.getOutputStream(); - ChartUtilities.writeChartAsPNG(os, chart, width, height); - os.flush(); } -} +} \ No newline at end of file