public class NumberDemo { public static void main(String[] args) { String str1="1122.2.2"; String str2="111"; String str3="111.2"; String str4="111s"; String str5="111.s"; String str6="1s11"; System.out.println(str1+":"+isNum(str1)); System.out.println(str2+":"+isNum(str2)); System.out.println(str3+":"+isNum(str3)); System.out.println(str4+":"+isNum(str4)); System.out.println(str5+":"+isNum(str5)); System.out.println(str6+":"+isNum(str6)); } public static boolean isNum(String str){ return str.matches("^[-+]?(([0-9]+)([.]([0-9]+))?|([.]([0-9]+))?)$"); } }
结果:
1122.2.2:false 111:true 111.2:true 111s:false 111.s:false 1s11:false