dbconnection.java

网上商城代码

package com.fendou.platform;

import java.sql.*;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;


public class DBConnection {
	private static DBConnection instance;
	private DataSource datasource;	
	private DBConnection(){	
		Context context;
		try {
			context = new InitialContext();
			datasource=(DataSource)context.lookup("java:comp/env/jdbc/test");
		} catch (NamingException e) {
			System.out.println(e);
		} 	
	}
	public static final DBConnection getInstance() {
        if (instance == null) {
            try {
                instance = new DBConnection();
            } catch (Exception e) {
            	System.out.println(e);
            }
        }
        return instance;
    }
	
	public synchronized final Connection getConnection() {
        try {
        	 return datasource.getConnection();
        } catch (SQLException e) {
        	System.out.println(e);
        }
        return null;
    }
	
	public void closeConnection(Connection conn,Statement stm){
		try{
			if(conn!=null)
				conn.close();
			if(stm!=null)
				stm.close(); 
		}catch(SQLException e){
			System.out.println(e);
		}
	}
	
	public  void closeConnection(Connection conn,Statement stm,ResultSet rs){
		try{
			if(conn!=null)
				conn.close();
			if(stm!=null)
				stm.close(); 
			if(rs!=null)
				rs.close();
		}catch(SQLException e){
			System.out.println(e);
		}
	}
	
	public  void closeConnection(Connection conn,PreparedStatement stm){
		try{
			if(conn!=null)
				conn.close();
			if(stm!=null)
				stm.close(); 
		}catch(SQLException e){
			System.out.println(e);
		}
	}
	
	public  void closeConnection(Connection conn,PreparedStatement stm,ResultSet rs){
		try{
			if(conn!=null)
				conn.close();
			if(stm!=null)
				stm.close(); 
			if(rs!=null)
				rs.close();
		}catch(SQLException e){
			System.out.println(e);
		}
	}
	
}