dbutility.java

bbs论坛系统

package struts.business;

import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

public class DBUtility {
	
	private static DBUtility instance;
	
	private String driver;
	private String url;
	private String user;
	private String password;
	
	private DBUtility()throws Exception
	{
		InputStream in=getClass().getClassLoader().getResourceAsStream
		("database.properties");
		Properties prop=new Properties();
		prop.load(in);
		driver=prop.getProperty("driver");
		url=prop.getProperty("url");
		user=prop.getProperty("user");
		password=prop.getProperty("password");
		Class.forName(driver);
				
	}
	public static DBUtility getInstance()
	{
		try{
			if(instance==null)
			{
				instance=new DBUtility();
			}
			return instance;
		}
		
		catch(Exception e)
		{
			e.printStackTrace();
			return null;
		}
	}
	public Connection getConnection() throws SQLException
	{
		Connection con;
		try
		{
			con=DriverManager.getConnection(url,user,password);
			
		}
		catch(SQLException e)
		{
			e.printStackTrace();
			throw e;
		}
	   return con;
	}
   
	public void closeConnection(Connection con)
	{
		if(con!=null)
		{
			try
			{
				con.close();
			}
			catch(SQLException e)	
			{
				e.printStackTrace();
			}
		}
	}
	public static void main(String args[])
	{
		try{
			DBUtility du=new DBUtility();
			System.out.print(du.url);
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
		
	}
	
}