Java验证是否为纯数字

package rbq.codedemo;

import java.util.regex.Pattern;

/**
 * Created by rbq on 2016/12/13.
 */

public class NumUtils {

    public static boolean isNum(String str){

        Pattern pattern = Pattern.compile("^-?[0-9]+");
        if(pattern.matcher(str).matches()){
            //数字
            return true;
        } else {
            //非数字
            return false;
        }
    }

    public static boolean isNum1(String str){
        //带小数的
        Pattern pattern = Pattern.compile("^[-+]?[0-9]+(\.[0-9]+)?$");

        if(pattern.matcher(str).matches()){
            //数字
            return true;
        } else {
            //非数字
            return false;
        }
    }

}