testtablemodel.java

疯狂Java讲义_源码(含Java设计模式CHM

import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.event.*;
import java.sql.*;
import java.io.*;
import javax.sql.rowset.*;
import com.sun.rowset.*;


/**
 * Description:
 * <br/>Copyright (C), 2005-2008, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee [e-mail]
 * @version  1.0
 */
public class TestTableModel
{
	JFrame jf = new JFrame("数据表管理工具");
	private JScrollPane scrollPane;
	private ResultSetTableModel model;
	//用于装载数据表的JComboBox
	private JComboBox tableNames = new JComboBox();
	private JTextArea changeMsg = new JTextArea(4, 60);
	private ResultSet rs;
	private Connection conn;
	private Statement stmt;

	public void init()
	{
		//为JComboBox添加事件监听器，当用户选择管理其他数据表
		tableNames.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent event)
			{
				try
				{
					//如果装载JTable的JScrollPane不为空
					if (scrollPane != null)
					{
						//从主窗口中删除表格
						jf.remove(scrollPane);
					}
					//从JComboBox中取出用户试图管理的数据表的表名
					String tableName = (String) tableNames.getSelectedItem();
					//如果结果集不为空，则关闭结果集
					if (rs != null) 
					{
						rs.close();
					}
					String query = "select * from " + tableName;
					//查询用户选择的数据表
					rs = stmt.executeQuery(query);
					//使用查询到的ResultSet创建TableModel对象
					model = new ResultSetTableModel(rs);
					//为TableModel添加监听器，监听用户的修改
					model.addTableModelListener(new TableModelListener()
					{
						public void tableChanged(TableModelEvent evt)
						{
							int row = evt.getFirstRow();
							int column = evt.getColumn();
							changeMsg.append("修改的列:" + column  + " ，修改的行:" + row
								+ " ，修改后的值:" + model.getValueAt(row , column));
						}
					});
					//使用TableModel创建JTable，并将对应表格添加到窗口中
					JTable table = new JTable(model);
					scrollPane = new JScrollPane(table);
					jf.add(scrollPane, BorderLayout.CENTER);
					jf.validate();
				}            
				catch (SQLException e)
				{  
					e.printStackTrace();
				}
			}
		});
		JPanel p = new JPanel();
		p.add(tableNames);
		jf.add(p, BorderLayout.NORTH);
		jf.add(new JScrollPane(changeMsg), BorderLayout.SOUTH);
		try
		{
			//获取数据库连接
			conn = getConnection();
			//获取数据库的MetaData对象
			DatabaseMetaData meta = conn.getMetaData();
			//创建Statement
			stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
				ResultSet.CONCUR_UPDATABLE);
			//查询当前数据库的全部数据表
			ResultSet tables = meta.getTables(null, null, null, new String[] { "TABLE" });
			//将全部数据表添加到JComboBox中
			while (tables.next())
			{
				tableNames.addItem(tables.getString(3));
			}
			tables.close();
		}
		catch (IOException e)
		{  
			e.printStackTrace();
		}
		catch (Exception e)
		{  
			e.printStackTrace();
		}

		jf.addWindowListener(new WindowAdapter()
		{
			public void windowClosing(WindowEvent event)
			{
				try
				{
					if (conn != null) conn.close();
				}
				catch (SQLException e)
				{
					e.printStackTrace();
				}              
			}
		});

		jf.pack();
		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		jf.setVisible(true);
	}
	
	private static Connection getConnection()
		throws SQLException, IOException ,ClassNotFoundException
	{
		//通过加载conn.ini文件来获取数据库连接的详细信息
		Properties props = new Properties();
		FileInputStream in = new FileInputStream("conn.ini");
		props.load(in);
		in.close();
		String drivers = props.getProperty("jdbc.drivers");
		String url = props.getProperty("jdbc.url");
		String username = props.getProperty("jdbc.username");
		String password = props.getProperty("jdbc.password");
		//加载数据库驱动
		Class.forName(drivers);
		//取得数据库连接
		return DriverManager.getConnection(url, username, password);
	}

	public static void main(String[] args) 
	{
		new TestTableModel().init();
	}
}
//扩展AbstractTableModel，用于将一个ResultSet包装成TableModel
class ResultSetTableModel extends AbstractTableModel
{  
	private ResultSet rs;
	private ResultSetMetaData rsmd;
	//构造器，初始化rs和rsmd两个属性
	public ResultSetTableModel(ResultSet aResultSet)
	{
		rs = aResultSet;
		try
		{  
			rsmd = rs.getMetaData();
		}
		catch (SQLException e)
		{  
			e.printStackTrace();
		}
	}
	//重写getColumnName方法，用于为该TableModel设置列名
	public String getColumnName(int c)
	{  
		try
		{  
			return rsmd.getColumnName(c + 1);
		}
		catch (SQLException e)
		{  
			e.printStackTrace();
			return "";
		}
	}
	//重写getColumnCount方法，用于设置该TableModel的列数
	public int getColumnCount()
	{  
		try
		{  
			return rsmd.getColumnCount();
		}
		catch (SQLException e)
		{  
			e.printStackTrace();
			return 0;
		}
	}
	//重写getValueAt方法，用于设置该TableModel指定单元格的值
	public Object getValueAt(int r, int c)
	{  
		try
		{  
			rs.absolute(r + 1);
			return rs.getObject(c + 1);
		}
		catch(SQLException e)
		{  
			e.printStackTrace();
			return null;
		}
	}
	//重写getColumnCount方法，用于设置该TableModel的行数
	public int getRowCount()
	{  
		try
		{  
			rs.last();
			return rs.getRow();
		}
		catch(SQLException e)
		{  
			e.printStackTrace();
			return 0;
		}
	}
	//重写isCellEditable返回true，让每个单元格可编辑
	public boolean isCellEditable(int rowIndex, int columnIndex) 
	{
		return true;
	}
	//重写setValueAt方法，用于实现用户编辑单元格时，程序做出对应的动作
	public void setValueAt(Object aValue,
		int row,int column)
	{
		try
		{
			//结果集定位到对应的行数
			rs.absolute(row + 1);
			//修改单元格多对应的值
			rs.updateObject(column + 1 , aValue);
			//提交修改
			rs.updateRow();
			//触发单元格的修改事件
			fireTableCellUpdated(row, column);
		}
		catch (SQLException evt)
		{
			evt.printStackTrace();
		}
	}
}