//isNumber:判断字符串是否是数字
System.out.println(NumberUtils.isNumber("5.96"));//true
System.out.println(NumberUtils.isNumber("ay1"));//false
System.out.println(NumberUtils.isNumber("100424030"));//true
System.out.println(NumberUtils.isNumber("1#$"));//false
module-info.java来声明一个模块，一个模块只能有一个文件，且在顶层包同目录下(List<String> list) -> list.isEmpty()() -> new Apple(10)(Apple a) -> {System.out.println(a.getWeight());}(String s) -> s.length()(int a, int b) -> a * b(Apple a1, Apple a2) ->a1.getWeight().compareTo(a2.getWeight())