String s = Integer.toString(new Date().getHours()); //比如现在是上午9点
//System.out.println(Integer.toString(s));
String a="9";
String b="9";
System.out.println(s == b); return false
System.out.println(s.equals(b)); return true
System.out.println(a == b); return true
System.out.println(f.getName()); 输出时dumps
但是 f.getName() == "dumps" 还是false
记得要用equals