单科成绩.java

经过调查分析

/*
 * 单科成绩.java
 *
 * Created on 2008年10月12日, 下午2:09
 */

package javaapplication1;
import java.awt.*;
import java.sql.*;
import java.util.*;
import javax.swing.*;
/**
 *
 * @author  mis06
 */
public class 单科成绩 extends javax.swing.JPanel {
    
    /** Creates new form 单科成绩 */
    public 单科成绩() {
        initComponents();
    }
    
    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:initComponents
    private void initComponents() {
        jLabel1 = new javax.swing.JLabel();
        jTextField1 = new javax.swing.JTextField();
        jButton1 = new javax.swing.JButton();
        jScrollPane1 = new javax.swing.JScrollPane();
        jTextArea1 = new javax.swing.JTextArea();

        jLabel1.setText("\u8bfe\u7a0b\u53f7");

        jButton1.setText("\u67e5\u8be2");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jTextArea1.setColumns(20);
        jTextArea1.setRows(5);
        jScrollPane1.setViewportView(jTextArea1);

        org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .add(75, 75, 75)
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
                    .add(layout.createSequentialGroup()
                        .add(jLabel1)
                        .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                        .add(jTextField1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 97, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                        .add(jButton1))
                    .add(jScrollPane1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 234, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(111, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .add(29, 29, 29)
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.BASELINE)
                    .add(jLabel1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 25, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                    .add(jTextField1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                    .add(jButton1))
                .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                .add(jScrollPane1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 211, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(124, Short.MAX_VALUE))
        );
    }// </editor-fold>//GEN-END:initComponents

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
    
 try{
     String str=new String(jTextField1.getText()); 
     Statement statement;
      Connect con=new Connect();
      statement=con.con.createStatement();
      String s1="SELECT  课程.课程号,课程.课程名,成绩.成绩  FROM 课程,成绩 WHERE 成绩.学号=(SELECT 编号 FROM 用户 WHERE 状态='登录') AND 成绩.课程号='"+str+"' AND 课程.课程号='"+str+"'";
      ResultSet resultSet=statement.executeQuery(s1);
    
    StringBuffer results=new StringBuffer();
    ResultSetMetaData metaData=resultSet.getMetaData();
    int numberOfColumns=metaData.getColumnCount();
    
      for(int i=1;i<=numberOfColumns;i++)
       results.append(metaData.getColumnName(i)+"\t");
          results.append("\n");
     
          while(resultSet.next())
       {  
        for(int i=1;i<=numberOfColumns;i++)
          results.append(resultSet.getObject(i)+"\t");
        results.append("\n");
       }
          
          jTextArea1.setText(results.toString());
          jTextArea1.setEditable(false);
    }
  
        catch(SQLException sqlException){
        JOptionPane.showMessageDialog(null,sqlException.getMessage(),"Database Error",JOptionPane.ERROR_MESSAGE);
        System.exit(1);}

   catch(ClassNotFoundException classNotFound){
       JOptionPane.showMessageDialog(null,classNotFound.getMessage(),"Driver Not Found",JOptionPane.ERROR_MESSAGE);
        System.exit(1);}// TODO add your handling code here:
    }//GEN-LAST:event_jButton1ActionPerformed
    
    
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton jButton1;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTextArea jTextArea1;
    private javax.swing.JTextField jTextField1;
    // End of variables declaration//GEN-END:variables
    
}