readerdelete.java

采用java+sql实现图书管理系统

import java.awt.*;//
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;

public class ReaderDelete
    extends JFrame
    implements ActionListener {
  DataBaseManager db = new DataBaseManager();
  ResultSet rs;//返回查询的结果集
  Container c;//Container继承于Componet
  JLabel TipLabel = new JLabel("请输入要删除的读者学号：", JLabel.CENTER);//显示标签
  JTextField readerDeleteTextField = new JTextField(15);//创建可以编辑的删除文本框
  JButton yesBtn, exitBtn;//创建两个选择按钮，“确定”与“退出”
  JPanel panel1 = new JPanel();
  public ReaderDelete() {
    super("删除读者信息");
    c = getContentPane();
    c.setLayout(new BorderLayout());//页面设置布局
    c.add(TipLabel, BorderLayout.NORTH);//显示在北面
    c.add(readerDeleteTextField, BorderLayout.CENTER);//编辑框在中间，输入书名
    yesBtn = new JButton("确定");
    exitBtn = new JButton("退出");
    yesBtn.addActionListener(this);//侦听
    exitBtn.addActionListener(this);
    panel1.add(yesBtn);//按钮增加到面板
    panel1.add(exitBtn);
    c.add(panel1, BorderLayout.SOUTH);//按钮在南面
  }
   //事件发生的处理操作
 public void actionPerformed(ActionEvent e) {
    try {
      if (e.getSource() == exitBtn) {//取消
        db.closeConnection();
        this.dispose();
      }
      else if (e.getSource() == yesBtn) {//确定删除
        String strSQL = "select * from readers where Readerno='" +
            readerDeleteTextField.getText().trim() + "'";
        if (readerDeleteTextField.getText().trim().equals("")) {
          JOptionPane.showMessageDialog(null, "学号不能为空！");
        }
        else if (db.getResult(strSQL).first()) {
          strSQL = "delete from readers where Readerno='" +
              readerDeleteTextField.getText().trim() + "'";
          if (db.updateSql(strSQL)>0) {
            JOptionPane.showMessageDialog(null, "删除成功!");
            this.dispose();
            }
          else {
            JOptionPane.showMessageDialog(null, "删除失败！");
            this.dispose();
          }

          db.closeConnection();
        }
        else {
          JOptionPane.showMessageDialog(null, "不存在此读者！");
        }
      }
    }
      catch (SQLException sqle) {
        System.out.println(sqle.toString());//数据库连接失败
      }
      catch (Exception ex) {
        System.out.println(ex.toString());
      }
    }
  }