asdasdasd.java

这是一个仿QQ的聊天程序

package com.cloudcloud.soft;

import java.sql.*;
import java.util.*;

public class asdasdasd
{
	String classname;
	String url;
	String username;
	String password;
	
	asdasdasd(String path)
	{
		try
		{
			asdsd fio = new asdsd(path);
			classname = fio.readLine();
			url = fio.readLine();
			username = fio.readLine();
			password = fio.readLine();
		}
		catch(Exception e)
		{
			
		}
	}
	public String isNull(String SQLstr)
	{
		try 
		{
			Class.forName(classname);
			Connection cn = DriverManager.getConnection(url,username,password);
			Statement st = cn.createStatement();
			ResultSet rs = st.executeQuery(SQLstr);
			
			boolean isNull = (!rs.next());
			st.close();
			if(isNull)
			{
				return "NULL";
			}
			else
			{
				return "NOTNULL";
			}
		}
		catch (Exception e)
		{
			return "ERROR";
		}	
	}
	public void insertData(String SQLstr)
	{
		try 
		{
			Class.forName(classname);
			Connection cn = DriverManager.getConnection(url,username,password);
			Statement st = cn.createStatement();
			st.executeUpdate(SQLstr);
			st.close();
		}
		catch (Exception e)
		{
			e.printStackTrace();
		}
	}
	public String getOneData(String SQLstr)
	{
		String data = null;
		try
		{
			Class.forName(classname);
			Connection cn = DriverManager.getConnection(url,username,password);
			Statement st = cn.createStatement();
			ResultSet rs = st.executeQuery(SQLstr);
			while(rs.next())
			{
				data = rs.getString(1);
			}
			st.close();
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
		return data;
	}
	public ArrayList getAllDataToString(String SQLstr)
	{
		ArrayList data = new ArrayList();
		ListIterator li = data.listIterator();
		try
		{
			Class.forName(classname);
			Connection cn = DriverManager.getConnection(url,username,password);
			Statement st = cn.createStatement();
			ResultSet rs = st.executeQuery(SQLstr);
			while(rs.next())
			{
				for(int i = 0; i <= 7; i++)
				{
					li.add(rs.getString(i+1));
				}
			}
			rs.close();
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
		
		
		return data;
	}
}