使用JFreeChart显示您的Oracle数据库数据(5)

   /**
* Create Bar Chart showing salary of each employee.
    * 
* @param aOrientation Horizontal or Vertical orientation of bar chart.
* @return Bar Chart.
    */
public JFreeChart createSalaryPerFinanceEmployeeBarChart(
PlotOrientation aOrientation)
   {
JFreeChart barChart = null;

try
      {
final String QUERY_SALARY_PER_FINANCE_EMPLOYEE =
"SELECT first_name || ' ' || last_name AS Name, salary " +
"FROM employees " +
"WHERE department_id = 100";

final CategoryDataset barDataset =
new JDBCCategoryDataset( databaseAccess.getOracleDbConnection(),
QUERY_SALARY_PER_FINANCE_EMPLOYEE );

barChart =
ChartFactory.createBarChart( TITLE_SALARY_PER_FINANCE_EMP, // title
LABEL_EMPLOYEES_FINANCE, // x-axis label
LABEL_SALARIES,          // y-axis label
barDataset,
aOrientation,
true,      // legend displayed
true,      // tooltips displayed
false );   // no URLs

      }
catch (SQLException sqlEx)
      {
// . . . exception handling goes here . . .
      }    

return barChart;
   }
. . .

JFrame frame = new JFrame(aTitle);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

JFreeChart barChart =
createSalaryPerFinanceEmployeeBarChart(
PlotOrientation.VERTICAL);
         
BufferedImage image = barChart.createBufferedImage(750,450);
JLabel label = new JLabel();
label.setIcon(new ImageIcon(image));
frame.getContentPane().add(label);

frame.pack();
frame.setVisible(true);