9.2.2  Example of creating a image file by the server side 

The second example shows a JSP listing of how to create the graph, encode it to a JPEG image file and 

provide a link to the file. The example is much the same as in chapter 9.2.1. 

<% 

  response.reset(); 

/* Init the chart object and set it's size */ 

  com.klg.jclass.chart.beans.SimpleChart chart = new 

com.klg.jclass.chart.beans.SimpleChart(); 

  chart.setSize(new java.awt.Dimension(500,300)); 

/* Fetch the graph data using a XfijFinder component. The graph will show 

lengths of lab test results (field number  6  in file  80001 ) in a simple plot 

graph connected with lines. */ 

  xfij.core.XfijFinder finder = new xfij.core.XfijFinder(); 

  finder.setFileNumber(new xfij.editor.FileNumber("80001")); 

  finder.setWRPCBroker(laboratoriotutkimusBean.getBroker()); 

  finder.setFields(new String[] { "6" }); 

  String[] results = finder.getList(); 

/* Create a TableModel that is used as data source by the graph component and 

create the actual graph image. */

  javax.swing.table.TableModel model = 

xfij.util.ChartUtil.ResultsToTableModel(results, false); 

  chart.setSwingDataModel(model); 

  chart.setXAxisTitleText("Record number"); 

  chart.setYAxisTitleText("The length of result"); 

  chart.repaint(); 

/* Save the image into a file  testImage.png . The session id string is added to 

the file name, because we need to provide access for many clients (sessions) at 

same time */ 

  java.io.File file = new 

java.io.File(application.getRealPath("testImage"+session.getId()+".png")); 

  xfij.util.ChartUtil.encode(chart.serverSnapshot(), "PNG", new 

java.io.FileOutputStream(file)); 

%> 

/* Provide the image to the client browser */ 

The downside of this technique is that the images must be deleted from the server by the application or they 

will remain there. 

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