package com.jdbclab;
import java.sql.*;

public class JdbcUtil
{   
	/*private static String driver=
		"com.mysql.jdbc.Driver";
	private static String url=
		"jdbc:mysql://127.0.0.1:3306/test";
	private static String username="root";
	private static String pwd="1234";*/
	/*private static String[] props =
	{"com.mysql.jdbc.Driver",
	 "jdbc:mysql://127.0.0.1:3306/test",
	 "root",
	 "1234"};*/
	private static String[] props = {
	 "oracle.jdbc.driver.OracleDriver",
     "jdbc:oracle:thin:@192.168.0.23:1521:tarena",
	 "openlab",
	 "open123"
	};
	//1、加載驅動
    static{
	  try{
	    Class.forName(props[0]);
	  }catch(Exception e){
	    e.printStackTrace();
	  }
	}
	//2、獲取連接
	public static Connection getConnection(){
	  Connection con = null;
	  try{
	    con = DriverManager.getConnection(
			props[1],props[2],props[3]);
	  }catch(Exception e){
	    e.printStackTrace();
	  }
	  return con;
	}
	//3、釋放資源
	public static void release(Object o){
	   try{
	     if(o instanceof ResultSet){
			 ((ResultSet)o).close();
	     }else if(o instanceof Statement){
		   ((Statement)o).close();
		 }else if(o instanceof Connection){
		   ((Connection)o).close();
		 }
	   }catch(Exception e){
	     e.printStackTrace();
	   }
	}
	public static void release(
		ResultSet rs,Statement stmt,Connection con){
      if(rs!=null){
	    try{
		  rs.close();
		}catch(Exception e){
		  e.printStackTrace();
		}
	  }

	  if(stmt!=null){
	    try{
		  stmt.close();
		}catch(Exception e){
		  e.printStackTrace();
		}
	  }

	  if(con!=null){
	    try{
		  con.close();
		}catch(Exception e){
		  e.printStackTrace();
		}
	  }

	}
	public static void printRs(ResultSet rs){
	  if(rs==null) return;
	  try{
	   ResultSetMetaData md = rs.getMetaData();
	   int num = md.getColumnCount();
	   StringBuffer sb = new StringBuffer();
	   for(int i=1;i<=num;i++){
	    int size = md.getColumnDisplaySize(i);
		if(size!=0){
		  String cname = md.getColumnName(i);
		  int blank = (size-cname.length())/2;
		  for(int j=0;j<blank;j++) sb.append(" ");
		  sb.append(cname);
		  if((size-cname.length())%2!=0) blank++;
		  for(int j=0;j<blank;j++) sb.append(" ");
	    }
	   }
	   sb.append("\n");
	   while(rs.next()){
	    for(int i=1;i<=num;i++){
	       int size = md.getColumnDisplaySize(i);
		   if(size!=0){
		     String value = rs.getString(i);
		     int blank = (size-value.length())/2;
		     for(int j=0;j<blank;j++) sb.append(" ");
		     sb.append(value);
		     if((size-value.length())%2!=0) blank++;
		     for(int j=0;j<blank;j++) sb.append(" ");
	       }
		}
		sb.append("\n");
	   }
	   System.out.println(sb.toString());
	  }catch(Exception e){
	   e.printStackTrace();
	  }
	}
}