使用JFreeChart显示您的Oracle数据库数据(8)

   /**
* Create 3D bar chart representing salaries of shipping clerks.
    * 
* @param aOrientation Horizontal or Vertical orientation.
* @return 3D bar chart.
    */
public JFreeChart createSalaryPerShippingClerkBarChart3D(
PlotOrientation aOrientation)
   {
JFreeChart barChart = null;
      
try
      {
final String QUERY_SALARY_PER_SHIPPING_CLERK =
"SELECT first_name || ' ' || last_name AS name, salary " +
"FROM employees " +
"WHERE job_id = 'SH_CLERK'";
final CategoryDataset barDataset =
new JDBCCategoryDataset( databaseAccess.getOracleDbConnection(),
QUERY_SALARY_PER_SHIPPING_CLERK );

barChart =
ChartFactory.createBarChart3D( TITLE_COUNTRIES_PER_REGION, // title
LABEL_SHIPPING_CLERKS,
LABEL_SALARIES,
barDataset,
aOrientation,
true,      // legend displayed
true,      // tooltips displayed
false );   // no URLs
      }
catch (SQLException sqlEx)
      {
// exception handling code . . .
      }
      
return barChart;
   }

/**
* Write .svg file based on provided JFreeChart.
    * 
* @param aChart Chart to be written out as SVG.
* @param aFileName Name of file (without extension) to hold SVG XML.
* @param aWidth Width of image.
* @param aHeight Height of image.
    */
public void writeSvgBasedOnChart( JFreeChart aChart,
String aFileName,
int aWidth,
int aHeight )
   {
final String fileExtension = ".svg";
final String svgNS = SVGDOMImplementation.SVG_NAMESPACE_URI;
final DOMImplementation dom =
GenericDOMImplementation.getDOMImplementation();
org.w3c.dom.Document document = dom.createDocument(svgNS, "svg", null);
SVGGraphics2D svgGraphic = new SVGGraphics2D(document);
aChart.draw( svgGraphic, new java.awt.Rectangle(aWidth, aHeight) );
      
try
      {
boolean useCSS = true; // we want to use CSS style attributes
OutputStream outputStream =
new FileOutputStream(aFileName + fileExtension);
Writer output = new OutputStreamWriter(outputStream, "UTF-8");
svgGraphic.stream(output, useCSS);                                           
outputStream.flush();
outputStream.close();
      }
catch (IOException ioEx)
      {
System.err.println("Problem encountered trying to write SVG file: ");
ioEx.printStackTrace();
      }
   }