1.int和Integer、long和Long各种相等不相等   https://www.cnblogs.com/guodongdidi/p/6953217.html   2.String a="abc",b="ab"+"c",c=new String("ab")+"c"; ==吗   https://blog.csdn.net/qq_34490018/article/details/82110578   3.这三个方法的关系,同时执行   public void f1(){     synchronized (this){...