JAVA实现的图书管理数据库操作

// Borrow.java package MainPro; import java.awt.*; import java.awt.event.*; import java.sql.*; import java.text.SimpleDateFormat; import java.util.Date; import javax.swing.JOptionPane; import PublicModule.*; public class Borrow extends Frame { private static final long serialVersionUID = -1036076990599464079L; String SepLine = "-------------------------------------------------"; Label lbbookid = new Label("图书编号"); Label lbreaderid = new Label("读者编号"); TextField tf_bookid = new TextField(); TextField tf_readerid = new TextField(); Button queryBtn = new Button("查询"); Label lbbookinfo = new Label(SepLine + "图书信息" + SepLine); Label lbbookname = new Label("图书名称："); Label tf_bookname = new Label("xx"); Label lbauthor = new Label("作者："); Label tf_author = new Label("xx"); Label lbpublisher = new Label("出版社："); Label tf_publisher = new Label("xx"); Label lbpublish_time = new Label("出版时间："); Label tf_publish_time = new Label("xx"); Label lbprice = new Label("定价："); Label tf_price = new Label("xx"); Label lbstock = new Label("库存数量："); Label tf_stock = new Label("xx"); Label lbreaderinfo = new Label(SepLine + "读者信息" + SepLine); Label lbreadername = new Label("读者姓名："); Label tf_readername = new Label("xx"); Label lbreadertype = new Label("读者类型："); Label tf_readertype = new Label("xx"); Label lbmax_num = new Label("最大可借数："); Label tf_max_num = new Label("xx"); Label lbdays_num = new Label("最大可借天数："); Label tf_days_num = new Label("xx"); Label lbborrowinfo = new Label(SepLine + "借阅信息" + SepLine); Label lbborrowednum = new Label("该读者已借图书数量："); Label tf_borrowednum = new Label("xx"); Label lbif_borrow = new Label("该读者是否可借所选图书："); Label tf_if_borrow = new Label("xx"); Label lbborrow_date = new Label("借阅日期："); Label tf_borrow_date = new Label("xx"); Button borrowBtn = new Button("借出"); Button closeBtn = new Button("关闭"); public Borrow() { setLayout(null); setTitle("借阅图书"); setSize(500, 420); this.setForeground(Color.BLACK); // 设置前景色为黑色 lbbookid.setBounds(30, 40, 50, 25); // 图书编号 tf_bookid.setBounds(90, 40, 90, 20); lbreaderid.setBounds(200, 40, 50, 25); // 读者编号 tf_readerid.setBounds(260, 40, 90, 20); queryBtn.setBounds(370, 40, 80, 25); // 查询按钮 lbbookinfo.setBounds(30, 70, 440, 25); // 图书信息提示条 lbbookname.setBounds(30, 100, 60, 25); // 图书名称 tf_bookname.setBounds(90, 100, 200, 25); lbauthor.setBounds(310, 100, 60, 25); // 作者 tf_author.setBounds(370, 100, 90, 25); lbpublisher.setBounds(30, 125, 60, 25); // 出版社 tf_publisher.setBounds(90, 125, 200, 25); lbpublish_time.setBounds(310, 125, 60, 25); // 出版时间 tf_publish_time.setBounds(370, 125, 90, 25); lbprice.setBounds(30, 150, 60, 25); // 定价 tf_price.setBounds(90, 150, 200, 25); lbstock.setBounds(310, 150, 60, 25); // 库存数量 tf_stock.setBounds(370, 150, 90, 25); lbreaderinfo.setBounds(30, 180, 440, 25); // 读者信息提示条 lbreadername.setBounds(30, 205, 60, 25); // 读者姓名 tf_readername.setBounds(90, 205, 90, 25); lbreadertype.setBounds(310, 205, 60, 25); // 读者类型 tf_readertype.setBounds(370, 205, 90, 25); lbmax_num.setBounds(30, 230, 75, 25); // 最大可借数 tf_max_num.setBounds(105, 230, 90, 25); lbdays_num.setBounds(310, 230, 85, 25); // 最大可借天数 tf_days_num.setBounds(395, 230, 70, 25); lbborrowinfo.setBounds(30, 260, 440, 25); // 借阅信息提示条 lbborrowednum.setBounds(30, 285, 120, 25);// 已借图书数量 tf_borrowednum.setBounds(150, 285, 50, 25); lbif_borrow.setBounds(30, 310, 145, 25); // 是否可借 tf_if_borrow.setBounds(175, 310, 50, 25); lbborrow_date.setBounds(30, 335, 60, 25);// 借书日期 tf_borrow_date.setBounds(90, 335, 100, 25); borrowBtn.setBounds(160, 365, 80, 25);// 借出按钮 borrowBtn.setEnabled(false); // 开始时禁用借出按钮 closeBtn.setBounds(260, 365, 80, 25);// 关闭按钮 queryBtn.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { btn_querywActionPerformed(e); } }); borrowBtn.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { btn_borrowActionPerformed(e); } }); closeBtn.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { setForeground(Color.BLACK); // 设置前景色为黑色 dispose(); // 关闭窗体 } }); /* 关闭窗口 */ this.addWindowListener(new WindowAdapter() { // 重写windowClosing()方法 public void windowClosing(WindowEvent e) { setForeground(Color.BLACK); // 设置前景色为黑色 dispose(); // 关闭窗体 } }); add(lbbookid); add(lbreaderid); add(queryBtn); add(lbbookinfo); add(lbbookname); add(lbauthor); add(lbpublisher); add(lbpublish_time); add(lbprice); add(lbstock); add(lbreaderinfo); add(lbreadername); add(lbreadertype); add(lbmax_num); add(lbdays_num); add(lbborrowinfo); add(lbborrowednum); add(lbif_borrow); add(lbborrow_date); add(borrowBtn); add(closeBtn); setLocationRelativeTo(null); // 使窗体在屏幕上居中放置 setVisible(true); // 使窗体可见 setForeground(Color.RED); // 设置前景色为红色 add(tf_bookid); add(tf_readerid); add(tf_bookname); add(tf_author); add(tf_publisher); add(tf_publish_time); add(tf_price); add(tf_stock); add(tf_readername); add(tf_readertype); add(tf_max_num); add(tf_days_num); add(tf_borrowednum); add(tf_if_borrow); add(tf_borrow_date); } // 图书和读者查询 private void btn_querywActionPerformed(ActionEvent e) { String bookid = tf_bookid.getText(); String readerid = tf_readerid.getText(); // 如果图书编号或读者编号两者均为空，或者有一个为空，则返回 if (bookid.equals("") || readerid.equals("")) { JOptionPane.showMessageDialog(null, "图书编号和读者编号均不能为空！"); init(); // 重新初始化各参数并禁止借出按钮 return; } // 按编号查询图书，结果存入book对象中 Book book = BookSelect.SelectBookById(bookid); // 如果查询到结果，将其显示在各文本框中 if (book != null) { tf_bookname.setText(book.getBookname()); tf_author.setText(book.getAuthor()); tf_publisher.setText(book.getPublisher()); tf_publish_time.setText(book.getPublish_time().toString()); tf_price.setText(String.valueOf((book.getPrice()))); tf_stock.setText(String.valueOf(book.getStock())); } else { JOptionPane.showMessageDialog(null, "图书编号有误，查无此书！"); init(); // 重新初始化各参数并禁止借出按钮 return; } if (book.getStock() == 0) { JOptionPane.showMessageDialog(null, "图书已无库存，无法借阅！"); init(); // 重新初始化各参数并禁止借出按钮 return; } // 按编号查询读者，结果存入reader对象中 Reader reader = ReaderSelect.selectReaderById(readerid); // 如果查询到结果，将其显示在各文本框中 if (reader != null) { tf_readername.setText(reader.getReadername()); tf_readertype.setText(reader.getReadertype()); tf_max_num.setText(String.valueOf(reader.getMax_num())); tf_days_num.setText(String.valueOf(reader.getDays_num())); } else { JOptionPane.showMessageDialog(null, "读者编号有误，查无此人！"); init(); // 重新初始化各参数并禁止借出按钮 return; } // 查询指定读者是否已借过指定图书且未归还 if (IfBorrowBack.findbook(bookid, readerid)) { JOptionPane.showMessageDialog(null, "该读者已借阅所选图书，且未归还！"); init(); // 重新初始化各参数并禁止借出按钮 return; } // 统计读者所借图书数量 int borrowednum = statborrowednum(readerid); tf_borrowednum.setText(String.valueOf(borrowednum)); // 如果读者已借图书尚未超出其允许最大借书量，则允许其继续借阅所选图书 if (borrowednum < reader.getMax_num()) { tf_if_borrow.setText("是"); // 创建一个简单日期格式对象，注意：MM一定要用大写