~~~ package io.a6; import java.io.*; public class Test { public static void main(String[] args) throws Exception { String zfc = "111111111111"; System.out.println("字符串是 " + zfc); BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); zfc = br.readLine(); //如果直接输入回车的话，字符串就是一个空字符串 System.out.println("------------"); System.out.println(zfc + "aaaaaaa"); System.out.println(zfc.equals("")); System.out.println(zfc.equals(null)); } } ~~~