Arredondamento

gistfile1.java

import java.math.BigDecimal;
import java.math.RoundingMode;


public class Teste1 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		BigDecimal b1 = new BigDecimal("0.2");
		BigDecimal b2 = new BigDecimal("0.5");
		BigDecimal b3 = new BigDecimal("0.6");
		
		System.out.println(arr(b1));
		System.out.println(arr(b2));
		System.out.println(arr(b3));
	}
	
	
	private static String arr(BigDecimal b) {
		String r = "";
		
		BigDecimal bb = b.multiply(new BigDecimal("2"));
		
		try {
			bb.intValueExact();
			r = b.toString();
		} catch (Exception e) {
			try {
				BigDecimal bg = b.setScale(0,RoundingMode.UNNECESSARY);
				r = bg.toString();
			} catch (ArithmeticException ee) {
				BigDecimal bg = b.setScale(0,RoundingMode.HALF_UP);
				r = bg.toString();
			}
		}
		return r;
	}
}