pay.java

这是一个用jbuilder2005编写的图书管理系统

package bookmanage;

import java.awt.*;
import javax.swing.*;
import java.awt.Rectangle;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.sql.ResultSet;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
import java.sql.SQLException;

/**
 * <p>Title: 图书管理系统</p>
 *
 * <p>Description: Pay类是继承JDialog，是用来付罚款的</p>
 *
 * <p>Copyright: Copyright (c) 2006</p>
 *
 * <p>Company: 浙江工业大学信息学院计算机系</p>
 *
 * @author 曾文秋
 * @version 1.0
 */
public class Pay
    extends JDialog {
  public Pay(Frame owner, String title, boolean modal) {
    super(owner, title, modal);
    try {
      setDefaultCloseOperation(DISPOSE_ON_CLOSE);
      jbInit();
      pack();
    }
    catch (Exception exception) {
      exception.printStackTrace();
    }
  }

  public Pay() {
    this(new Frame(), "Pay", false);
  }

  private void jbInit() throws Exception {
    this.getContentPane().setLayout(null);
    jLabel1.setText("学号：");
    jLabel1.setBounds(new Rectangle(69, 40, 48, 20));
    jLabel2.setText("付款额：");
    jLabel2.setBounds(new Rectangle(69, 74, 48, 20));
    jTextFieldMoney.setBounds(new Rectangle(142, 74, 100, 20));
    jButtonPayCancel.setBounds(new Rectangle(178, 112, 81, 23));
    jButtonPayCancel.setText("取消");
    jButtonPayCancel.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jButtonPayCancel_actionPerformed(e);
      }
    });
    jButtonPayAlert.setBounds(new Rectangle(60, 112, 81, 23));
    jButtonPayAlert.setText("确定");
    jButtonPayAlert.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        jButtonPayAlert_actionPerformed(e);
      }
    });
    this.getContentPane().add(jButtonPayAlert);
    this.getContentPane().add(jButtonPayCancel);
    this.getContentPane().add(jLabel1);
    this.getContentPane().add(jLabel2);
    this.getContentPane().add(jTextFieldPayXuehao);
    this.getContentPane().add(jTextFieldMoney);
    jTextFieldPayXuehao.setBounds(new Rectangle(142, 40, 100, 20));
  }

  JLabel jLabel1 = new JLabel();
  JTextField jTextFieldPayXuehao = new JTextField();
  JLabel jLabel2 = new JLabel();
  JTextField jTextFieldMoney = new JTextField();
  JButton jButtonPayAlert = new JButton();
  JButton jButtonPayCancel = new JButton();
  //定义结果集
  ResultSet rs;
  //定义数据库操作对象
  private DBManager db = new DBManager();


  public boolean isNumeric(String str){
    Pattern pattern = Pattern.compile("[0-9,.]*");
    Matcher isNum = pattern.matcher(str);
    if( !isNum.matches() ){
      return false;
    }
    return true;
  }


  public void jButtonPayCancel_actionPerformed(ActionEvent e) {
    this.dispose();
  }

  public void jButtonPayAlert_actionPerformed(ActionEvent e) {
    String xuehao="";
    float money=0;
    xuehao=jTextFieldPayXuehao.getText().trim();
    if(xuehao.equals("")){
      JOptionPane.showMessageDialog(this, "学号许为空！");
      return;
    }
    if(jTextFieldMoney.getText().trim().equals("")){
      JOptionPane.showMessageDialog(this, "钱不许为空！");
      return;
    }
    if(isNumeric(jTextFieldMoney.getText().trim())){
      money=Float.parseFloat(jTextFieldMoney.getText().trim());
    }
    else{
      JOptionPane.showMessageDialog(this, "你输入的钱不是数字！");
      return;
    }

    String strSQL="";

    strSQL="select * from buser where xuehao='"+xuehao+"'";
    rs = db.getResult(strSQL);
    boolean isexist = false;
    try {
      isexist = rs.first();
    }
    catch (SQLException ex1) {
    }

    if (!isexist){
      JOptionPane.showMessageDialog(this, "没有这个学生，你可能还没有开通图书卡业务");
      return;
    }
    else{
      strSQL="update buser set penalty=penalty-"+money+" where xuehao='"+xuehao+"'";
      if (db.executeSql(strSQL)) {
        JOptionPane.showMessageDialog(this, "付款成功");
        this.dispose();
      }
      else {
        JOptionPane.showMessageDialog(this, " 付款失败，请重新操作！");
      }
    }


  }
}