java check if a string is numeric

/**
 * @author lautturi.com
 * Java example:determine whether  a string is numeric in java 
 */

import java.util.*;

public class Lautturi {

	public static boolean isNumeric(String str) {
		  return str.matches("-?\\d+(\\.\\d+)?");
		}
	
	public static void main(String[] args) {
		
		System.out.println(isNumeric("123"));
		System.out.println(isNumeric("-123"));
		System.out.println(isNumeric("123-"));
		System.out.println(isNumeric("123.0"));
		System.out.println(isNumeric("123.15"));
		System.out.println(isNumeric("abc"));
		System.out.println(isNumeric(" 123 "));

	}
}

output:

true
true
false
true
true
false
false