equals的问题

String类型以及基本数据类型的包装类都碎equals方法进行了重写，比较的是指本身，而其他类型除非也对equals方法重写，否则比较的是对象的应用地址

String s1 = "1";

String s2 = "1";

si.equals(s2)返回true

BuyNote buyNote = new BuyNote();
buyNote.setBuyNoteTitle(a);
buyNote.setBuyNoteContent(a);
BuyNote buyNote2 = new BuyNote();
buyNote2.setBuyNoteTitle(a);
buyNote2.setBuyNoteContent(a);

buyNote.equals(buyNote2)返回false