check whether string is number in java

/**
 * @author lautturi.com 
 * Java example: check if string is a numeric
 */

import java.util.*;

public class Lautturi {
	
	public static boolean isNumeric(String str) {
	    if (str == null) {
	        return false;
	    }
	    try {
	        double d = Double.parseDouble(str);
	    } catch (NumberFormatException nfe) {
	        return false;
	    }
	    return true;
	}

	public static void main(String[] args) {

		String str = "123";
		System.out.println(isNumeric(str));

		System.out.println(isNumeric("123.0"));
		System.out.println(isNumeric("123.0d"));
		System.out.println(isNumeric("123.0f"));
		System.out.println(isNumeric("123.0abc"));
		System.out.println(isNumeric("abc"));

	}
}

output:

true
true
true
true
false
false