userlistfrm.java

用java做的一个图书管理系统

import java.awt.*;
import java.awt.event.*;
import java.sql.*;

import javax.swing.*;

class Userlistfrm extends JFrame implements ActionListener
{
	Object a[][]; 
	Object colname[]={"id","用户名","密码"};
	JTable table;
	Container container;
	JButton b_enter,b_back;
	JProgressBar p_bar;
	JPanel pan1;
	
	NetConn  sql;
	Statement sqll;
	ResultSet rs;
	
	Userlistfrm()
	{
		 //界面布局
		super("用户列表");
		a=new Object[30][3];
		table=new JTable(a,colname);
		setSize(300,300);setVisible(true);
		b_enter=new JButton("确定");
		b_back=new JButton("返回");
		b_enter.addActionListener(this);
		b_back.addActionListener(this);
		pan1=new JPanel();
		pan1.add(b_enter);pan1.add(b_back);
		p_bar=new JProgressBar(JProgressBar.VERTICAL,0,50);
		p_bar.setStringPainted(true);
		container=getContentPane();
		container.add(pan1,BorderLayout.SOUTH);
		container.add(new JScrollPane(table),BorderLayout.CENTER);
		container.add(p_bar,BorderLayout.WEST);
		//建立数据库连接
		sql=new NetConn();
		//设置窗体大小
		setBounds(250,150,600,350);
	}
	public void  actionPerformed(ActionEvent eb)
	{
		//单击返回按钮的事件处理程序
		if(eb.getSource()==b_back)
		{
			dispose();
		}
		//单击确定按钮的事件处理程序
		else if(eb.getSource()==b_enter)
		{
			try
			{
				int i=0;
				sqll=sql.connect();
				//查询所有用户
				rs=sqll.executeQuery("select * from users");
				//循环显示所有用户列表
				while(rs.next())
				{
					a[i][0]=rs.getString(2);a[i][1]=rs.getString(3);a[i][2]=rs.getString(4);		
					i++;
					p_bar.setValue(i);;p_bar.setString("查询了"+i+"条记录");
				}
			}
			catch(SQLException ed)
			{
				
			}
		}
	}
}