FindSize

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

/**
* @author Uttesh Kumar T.H.
*/
public class FindSize {
	
	static long numberOfRecords=1000;
	
	public static void main(String[] args) throws IOException {
		testPrimitives(new LinkedList<Integer>());
		testPrimitives(new ArrayList<Integer>());
		testObjects(new LinkedList<User>());
		testObjects(new ArrayList<User>());
	}
	
	public static void populateListOfPrimitives(List<Integer> list) {
		for (int i = 0; i < numberOfRecords; i++) {
			list.add(new Integer(i * 10));
		}
	}
	
	public static void populateListOfObjects(List<User> list) {
		User user = null;
		for (int i = 0; i < numberOfRecords; i++) {
			user = new User();
			user.setName("user_"+i);
			user.setPassword("password_"+i);
			list.add(user);
		}
	}

	public static void testPrimitives(List<Integer> list) throws IOException {
		System.out.println("Primitives "+list.getClass().getSimpleName());
		populateListOfPrimitives(list);
		long size = getBytesFromList(list);
		printInUnits(size);
	}
	
	
	public static void testObjects(List<User> list) throws IOException {
		System.out.println("Objects "+list.getClass().getSimpleName());
		populateListOfObjects(list);
		long size = getBytesFromList(list);
		printInUnits(size);
	}
	
	public static long getBytesFromList(List list) throws IOException {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		ObjectOutputStream out = new ObjectOutputStream(baos);
		out.writeObject(list);
		out.close();
		return baos.toByteArray().length;
	}

	public static void printInUnits(long length) {
		System.out.println("list size is :: " + length / 1000000000 + " GB");
		System.out.println("list size is :: " + length / 1000000 + " MB");
		System.out.println("list size is :: " + length / 1000 + " kB");
		System.out.println("list size is :: " + length + " byte");
	}

}

class User implements Serializable{
	String name;
	String password;
	
	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}
	
	
}