dao.java

类似qq的以c/s结构和p2p结构结合的聊天软件。

package com.server;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

class Dao
{
	private static Connection conn=null;
    private static Statement stmt=null;
    private static ResultSet rs=null;
    private static String sqlstr=null;
    public Dao()
    {
    	try
	       {
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
		   }catch(ClassNotFoundException e){}
		try
		{
			String url="jdbc:odbc:usergrade";
			conn=DriverManager.getConnection(url);
			stmt=conn.createStatement();
		}catch(SQLException e){}
    }
    public ResultSet query(String sqlstr)
    {
    	this.sqlstr=sqlstr;
    	try
    	{
    		rs=stmt.executeQuery(sqlstr);
    	}catch(SQLException e){}
    	return rs;
    }
    
    public void update(String sqlstr)
    {
    	this.sqlstr=sqlstr;
    	try
    	{
    		stmt.executeUpdate(sqlstr);
    	}catch(SQLException e){}
    }
}