dbwindows.java.bak

database xiangguan... shujuku

//Java core packages
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import java.sql.DriverManager;
// Java extension packages
import javax.swing.*;

public class dbwindows extends JFrame
{
	public static void main(String args[]) 
	{
		dbwindows mcd = new dbwindows();
		mcd.setDefaultCloseOperation(
			JFrame.EXIT_ON_CLOSE);
	}
	
	private Container container; 
	private JButton execute,reset,exit;
	private JTextArea demand,result;
	private JLabel l1,l2,mark;
	
	public dbwindows()
	{
		super("A window for database management");
		container = getContentPane();
		container.setLayout(null); 
		execute = new JButton("Execute");
		exit = new JButton("Exit");
		reset = new JButton("Reset");
		
		demand = new JTextArea("",10,30);
		result = new JTextArea("",10,30);
		result.setEditable(false);
		
		l1 = new JLabel("SQL Query:");
		l2 = new JLabel("Query Result:");
		mark = new JLabel("Database Management Window -- 0361120");
		
		JScrollPane js1 = new JScrollPane(demand);
		JScrollPane js2 = new JScrollPane(result);
		
		js1.setBounds(25,50,550,200);
		js2.setBounds(25,290,680,300);
		execute.setBounds(600,75,100,35);
		reset.setBounds(600,125,100,35);
		exit.setBounds(600,175,100,35);
		l1.setBounds(25,25,100,25);
		l2.setBounds(25,265,100,25);
		mark.setBounds(400,600,300,30);
		
		execute.addActionListener
		(
		    new ActionListener() 
			{
		    	public void actionPerformed(ActionEvent actionEvent) 
				{
					//result.setText("");
					StringBuffer sqlbuffer = execsql(demand.getText());
					result.setText(sqlbuffer.toString());
				}      
	    	}
		);
		
		reset.addActionListener
		( 
			new ActionListener() 
			{
		        public void actionPerformed(ActionEvent actionEvent) 
		        {
		        	demand.setText("");
		        }
		    }
		);
		
		exit.addActionListener
		( 
			new ActionListener() 
			{
		        public void actionPerformed(ActionEvent actionEvent) 
		        {
		                System.exit(0);
		        }
		    }
		);
		
		container.add(js1);
		container.add(js2);
		container.add(execute);
		container.add(reset);
		container.add(exit);
		container.add(l1);
		container.add(l2);
		container.add(mark);
		
		setSize(750, 680); //set the size of the window
		setVisible(true); //make the window visible
	}
	
	/* transmit sql query to oracle to get the query results,
	 * and show the results in the result textarea
	 */
	public StringBuffer execsql(String sql)
	{
		StringBuffer resultString = new StringBuffer("");
		
		try
		{
			System.out.print(sql+"\n");
			/* connect to oracle database */
			Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
			String url="jdbc:oracle:thin:@localhost:1521:myoracle";
			String user = "db1";
			String password = "db1";
			Connection Con = DriverManager.getConnection(url,user,password);
			
			Statement stmt = Con.createStatement();
			ResultSet rs = stmt.executeQuery(sql);
			
			ResultSetMetaData rsmd = rs.getMetaData();
			
			resultString.append("\n");
			
			/* get each column */
			int col_num = rsmd.getColumnCount();
			if (col_num == 0)
			{
				System.out.print("无内容 \n");
				return resultString;
			}
			System.out.print(col_num);
			
			resultString.append("  ");
			for (int i=0; i<col_num; i++)
			{
				resultString.append(rsmd.getColumnName(i+1)+"\t\t");
			}
			
			resultString.append("\n");
			resultString.append("----------------------------------------------------\n");
			
			int rows=0;
			
			for (; rs.next();)
			{
				resultString.append("  ");
				for (int i=0; i<col_num; i++)
				{
					String type = rsmd.getColumnTypeName(i+1);
					if (type.equals("NUMBER"))
					{
						resultString.append(rs.getInt(i+1)+"\t\t");
					}
					else 
					{
						resultString.append(rs.getString(i+1)+"\t\t");
					}
				}
				resultString.append("\n");
				rows++;
			}
			resultString.append("----------------------------------------------------\n");
			if (rows==0)
			{
				resultString.append("未选定行");
			}
			else
				resultString.append("已选定"+rows+"行");
			
			rs.close();
			stmt.close();
			Con.close();
			
		}
		catch(Exception e)
		{
			System.err.println(e);
		}
		return resultString;
	}
	
}