写java代码作业时遇到问题，大神不要走，进来看一看吧，求帮助

具体如图，，我的图书号无法输入，没有输入的地方，，是我标签定义的有问题吗，自己无解，求帮助，谢谢

具体代码如下：

package com.zyp;

import java.awt.event.*;

import javax.swing.*;

import java.awt.*;

import java.awt.Container;

import java.util.*;

import java.sql.*;

class QueryBook implements ActionListener

{

JFrame f3;

Container cp;

JPanel jp1,jp2,jp3,jp4,jp,jpanelWest;

JButton jbt1,jbt2;//按钮，确定、取消

JLabel label; //标签：请输入图书号

JTextField tf,tf1,tf2,tf3,tf4,tf5,tf6; //定义文本框

JLabel label1,label2,label3,label4;

QueryBook()

{

f3=new JFrame();

cp=f3.getContentPane(); // 初始化面板、按钮、标签、文本框

jp1=new JPanel();

jp2=new JPanel();

jp3=new JPanel();

jp4=new JPanel();

jpanelWest=new JPanel();

jp=new JPanel();

jbt1=new JButton("确定");

jbt2=new JButton("取消");

label=new JLabel("<html><font color=#CC00FF size='4'>请输入图书号：</font>",SwingConstants.CENTER);

label.setForeground(Color.blue);

tf=new JTextField(20);

tf1=new JTextField(20);

tf2=new JTextField(20);

tf3=new JTextField(20);

tf4=new JTextField(20);

tf5=new JTextField(20);

tf6=new JTextField(20);

//布局,添加控件

JPanel jpanel=new JPanel();

jpanel.add(label);

jpanel.add(tf);

JPanel pp4=new JPanel();

JPanel jpane4=new JPanel();

cp.add(jpanel,"North");

JPanel pp2=new JPanel(new GridLayout(6,1));

JPanel pp3=new JPanel();

pp4.setLayout(new GridLayout(6,1));

pp4.add(new JLabel("图书名",SwingConstants.CENTER));

pp2.add(tf1);

pp4.add(new JLabel("图书号",SwingConstants.CENTER));

pp2.add(tf2);

pp4.add(new JLabel("单价",SwingConstants.CENTER));

pp2.add(tf3);

pp4.add(new JLabel("作者",SwingConstants.CENTER));

pp2.add(tf4);

pp4.add(new JLabel("出版社",SwingConstants.CENTER));

pp2.add(tf5);

pp4.add(new JLabel("入库时间",SwingConstants.CENTER));

pp2.add(tf6);

pp3.add(jbt1);

pp3.add(jbt2);

cp.add(pp4,"West");

cp.add(pp2,"Center");

cp.add(pp3,"South");

cp.add(jpane4,"East");

Toolkit kit=Toolkit.getDefaultToolkit();

Dimension screen=kit.getScreenSize();

int x=screen.width; /*取得显示器窗口的宽度*/

int y=screen.height; /*取得显示器窗口的高度*/

f3.setSize(350,330);

int xcenter=(x-350)/2;

int ycenter=(y-330)/2;

f3.setLocation(xcenter,ycenter);/*显示在窗口中央*/

f3.setVisible(true);

jbt1.addActionListener(this);//注册监听器

jbt2.addActionListener(this);

f3.addWindowListener(new WindowAdapter(){

public void windowClosing(WindowEvent e){

System.exit(0);

}

);

}

public void showRecord()

{

Connection con = null;

try{

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

}catch(ClassNotFoundException e){System.out.println("加载驱动程序失败!");}

try{

String url = "jdbc:sqlserver://localhost:1433;databasename=DB";//直接使用当前类目录下的数据库文件

String user= "zyp";

String password = "215";

con =DriverManager.getConnection(url, user, password);

Statement sql;

String ql=tf.getText().trim();

String s="select * from book where 图书号 ='"+ql +"'";

sql=con.createStatement();

ResultSet rs=sql.executeQuery(s);

if(rs.next())

{

String bname=rs.getString(1);

String bno=rs.getString(2);

String price=rs.getString(3);

String writer=rs.getString(4);

String publish=rs.getString(5);

String indate=rs.getString(6);

tf1.setText(bname);

tf2.setText(bno);

tf3.setText(price);

tf4.setText(writer);

tf5.setText(publish);

tf6.setText(indate);

}

else

{JOptionPane.showMessageDialog(null,"您输入的图书号不存在，请重新输入",

"输入错误", JOptionPane.YES_NO_OPTION);

}

con.close();

}catch(SQLException g)

{

System.out.println("E Code"+g.getErrorCode());

System.out.println("E M"+g.getMessage());

}

tf1.setEditable(false);

tf2.setEditable(false);

tf3.setEditable(false);

tf4.setEditable(false);

tf5.setEditable(false);

tf6.setEditable(false);

}

public void actionPerformed(ActionEvent e)

{

String cmd=e.getActionCommand();

if(cmd.equals("确定"))

{

showRecord();

tf.setText("");

}

else if(cmd.equals("取消"))

f3.hide();

}

public static void main(String []arg){

QueryBook a=new QueryBook();

}

Z见贤思齐

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