数据库连接池JDBC

package util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

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

public class JDBCORCALUtil2 {
//	public static final String driver = "oracle.jdbc.driver.OracleDriver";
//	public static final String url = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";
//	public static final String name = "yyd";
//	public static final String pwd = "yyd";
	Connection con = null;// 链接对象
	PreparedStatement ps = null;
	ResultSet rs = null;
	public static Context ctx;
	public static DataSource ds;

	static{//只会执行一次，并且是第一次调用时候自动执行
		try {
			ctx=new InitialContext();
			ds=(DataSource) ctx.lookup("java:comp/env/jdbc/rentcar");
		} catch (Exception e) {
			// TODO: handle exception
		}
		
		
	}
	
//	public Connection getcon() {
//
//		try {
//			Class.forName(driver);
//			con = DriverManager.getConnection(url, name, pwd);
//		} catch (Exception e) {
//			// TODO Auto-generated catch block
//			e.printStackTrace();
//		}
//
//		return con;
//
//	}
	
	public Connection getcon() {

		try {
			con=ds.getConnection();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

		return con;

	}

	public void closeAll() {
		try {
			if (rs != null)
				rs.close();
			if (ps != null)
				ps.close();
			if (con != null)
				con.close();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	

	
	public boolean update(String sql, Object...obj){
		int num=0;
		con = getcon();
		try {
	ps = con.prepareStatement(sql);
     if(obj!=null){
    	 
    	 for(int i=0;i<obj.length;i++){
    		 ps.setObject(i+1, obj[i]);
    	 }
     }
    num = ps.executeUpdate();
     
			 
		

		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			closeAll();
		}
		return num>0;
	}
	
	
	public ResultSet select(String sql, Object...obj){
		
		con = getcon();
		try {	
			
	ps = con.prepareStatement(sql);
     if(obj!=null){
	for(int i=0;i<obj.length;i++){
		ps.setObject(i+1, obj[i]);
	}
}
		rs = ps.executeQuery();

  
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
	
	}
	return rs;	
	}	
		
	

}