Iterator

[maggie joseph]

 
package com.mk;

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

public class New{
	
float variable;
Connection con;
ResultSet rs;
String s;
Statement st;
static String BillMonthYear;
 static float Principal;
 String d;
 public New(String s)
 {
 String BillMonthYear=getBillMonthYear();
 this.d=s;
 }

public New() {}
public New(float v) {
	
	float Principal=getPrincipal();
	String BillMonthYear=getBillMonthYear();
	this.variable=v;
	}
	
 public static void main(String args[]) 
 {
String url = "jdbc:postgresql://localhost/Books";
Connection con;
ResultSet rs;
String s;
Statement st;
		
String sqlstr = "SELECT \"BillMonthYear\",\"Principal\" FROM \"BookSchema\".\"Bill\"";
try 
{
Class.forName("org.postgresql.Driver");
		
con = DriverManager.getConnection(url,"postgres", "admin123");
st = con.createStatement();
rs = st.executeQuery(sqlstr);
			
List<New> b1=new ArrayList<New>();
while(rs.next()){
New bm=new New();
bm.setBillMonthYear(rs.getString(1));
bm.setPrincipal(rs.getString(2));
b1.add(bm);


Iterator<New> it=b1.iterator(); .............line1
  while (it.hasNext())..........................line 2
   {
      New b2=it.next();
      System.out.println(b2.variable+"b");
   }...................................................line 5
}      	System.out.println(b1.size()+"size");
    rs.close();
	st.close();
	con.close();
	
}
		catch(Exception ex) 
		{
			System.err.println("SQLException: " + ex.getMessage());
		}
	}
	public float getPrincipal() 
	{  
		return Principal;	
		}	
	public void setPrincipal(String pri) {
	
		float f=Float.parseFloat(pri);
		Principal=f;
		}
	public String getBillMonthYear() 
	{  
		return BillMonthYear;	
		}	
	public void setBillMonthYear(String pri) {
	
		BillMonthYear=pri;
		}

	
}   

i want to get the values of Principal and BillMonthYear ..how do i access the values...I am getting values as 0...
what do i put in lines 1,2 till line 5....??

thanks

[Ankit Garg]

1. Please indent your code properly, its almost unreadable.
2. The while loop that starts on line 49 ends at line 62, so if there are 3 rows in the database, you'll get 6 outputs (because the iterator will run with each row in the database)
3. You are only displaying the value of variable in the while loop which you never set so you'll get 0 as output. If you want the values of billMonthYear and principal, then you can change the code in the second while loop to

New b2=it.next();  
System.out.println(b2.BillMonthYear);
System.out.println(b2.Principal);

[Harpreet Singh janda]

Instance variables are always automatically initialized to default values and for the float the default value is 0. As you are not setting the value of "variable" so by default it's value will be 0.

[Jesper de Jong]

This question doesn't look like it has anything to do with the SCJP exam. I will move it to a more appropriate forum for you.

Please CarefullyChooseOneForum when you post a question.