removemembers.java

这个软件是一个图书管理系统

//import the packages for using the classes in them into the program
   import java.awt.*;
   import java.text.*;
   import java.util.*;
   import javax.swing.*;
   import java.awt.event.*;

/**
 *A public class
 */
   public class removeMembers extends JInternalFrame {
   /***************************************************************************
    ***      declaration of the private variables used in the program       ***
    ***************************************************************************/
   
   //for creating the North Panel
      private JPanel northPanel = new JPanel();
   //for creating the label
      private JLabel title = new JLabel("MEMBER INFORMATION");
   
   //for creating the Center Panel
      private JPanel centerPanel = new JPanel();
   //for creating an Internal Panel in the center panel
      private JPanel removePanel = new JPanel();
   //for creating the label
      private JLabel removeLabel = new JLabel("Member ID: ");
   //for creating the text field
      private JTextField removeTextField = new JTextField();
   //for creating string to store the data
      private String data;
   //for creating an Internal Panel in the center panel
      private JPanel removeMemberPanel = new JPanel();
   //for creating the button
      private JButton removeButton = new JButton("Remove");
   
   //for creating the South Panel
      private JPanel southPanel = new JPanel();
   //for adding the button
      private JButton exitButton = new JButton("Exit");
   
   //create objects from another classes for using them in the ActionListener
      private toDatabase dataToDatabase;
   //for checking the information from the text field
      public boolean isCorrect() {
         if(!removeTextField.getText().equals("")) {
            data = removeTextField.getText();
            return true;
         }
         else
            return false;
      }
   //constructor of removeMembers
      public removeMembers() {
      //for setting the title for the internal frame
         super("Remove Members", false, true, false, true);
      //for setting the icon
         setFrameIcon(new ImageIcon(ClassLoader.getSystemResource("images/Delete16.gif")));
      //for getting the graphical user interface components display area
         Container cp = getContentPane();
      
      //for setting the layout
         northPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
      //for setting the font
         title.setFont(new Font("Tahoma", Font.BOLD, 14));
      //for adding the label
         northPanel.add(title);
      //for adding the panel to the container
         cp.add("North", northPanel);
      
      //for setting the layout
         centerPanel.setLayout(new BorderLayout());
      //for setting the layout
         removePanel.setLayout(new GridLayout(1,2,1,1));
      //for adding the label
         removePanel.add(removeLabel);
      //for adding the text field
         removePanel.add(removeTextField);
      //for adding the internal panel to the panel
         centerPanel.add("Center", removePanel);
      
      //for setting the layout
         removeMemberPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
      //for adding the button
         removeMemberPanel.add(removeButton);
      //for addint the internal panel to the center panel
         centerPanel.add("South", removeMemberPanel);
      //for setting the border
         centerPanel.setBorder(BorderFactory.createTitledBorder("Remove a member:"));
      //for adding the center panel to the container
         cp.add("Center", centerPanel);
      
      /**
       *for setting the font for the label & buttons
       */
         removeLabel.setFont(new Font("Tahoma", Font.BOLD, 11));
         removeTextField.setFont(new Font("Tahoma", Font.PLAIN, 11));
         exitButton.setFont(new Font("Tahoma", Font.BOLD, 11));
         removeButton.setFont(new Font("Tahoma", Font.BOLD, 11));
      
      //for setting the layout
         southPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
      //for adding the button
         southPanel.add(exitButton);
      //for setting the border
         southPanel.setBorder(BorderFactory.createEtchedBorder());
      //for add the south panel to the container
         cp.add("South", southPanel);
      
      /***********************************************************************
       * for adding the action listener to the button,first the text will be *
       * taken from the JTextField and make the connection for database,     *
       * after that update the table in the database with the new value      *
       ***********************************************************************/
         removeButton.addActionListener(
                                 new ActionListener() {
                                    public void actionPerformed(ActionEvent ae) {
                                    //for checking if there is a missing information
                                       if(isCorrect()) {
                                          Thread runner = 
                                             new Thread() {
                                                public void run() {
                                                   dataToDatabase = new toDatabase();
                                                //for checking if the user borrowed any book form the library
                                                   if(dataToDatabase.isDouble("SELECT ID FROM Members WHERE MemberID = " + data + " AND NumberOfBooks = 0")) {
                                                      dataToDatabase.update("DELETE FROM Members WHERE MemberID = " + data);
                                                   //for setting the JTextField to null
                                                      removeTextField.setText(null);
                                                   }
                                                   else
                                                      JOptionPane.showMessageDialog(null,"Book(s) borrowed by the member","Warning",JOptionPane.WARNING_MESSAGE);
                                                }
                                             };
                                          runner.start();
                                       }
                                       //if there is a missing data, then display Message Dialog
                                       else {
                                          JOptionPane.showMessageDialog(null,"Please, complete the information","Warning",JOptionPane.WARNING_MESSAGE);
                                       }
                                    }
                                 });
      //for adding the action listener for the button to dispose the frame
         exitButton.addActionListener(
                                 new ActionListener() {
                                    public void actionPerformed(ActionEvent ae) {
                                       dispose();
                                    }
                                 });
      //for setting the visible to true
         setSize(300,180);
         setVisible(true);
      //show the internal frame
        // pack();
      }
   }