使用TreeSet时，若需去除重复对象（重复指UserInfo对象的userId和userName两个属性值均相同），应重写该类的equals()和hashCode()方法，确保对象去重逻辑正确，避免因未定义比较规则而导致集合中出现重复元素，从而保证数据唯一性和集合操作的准确性。

If you are fortunate enough to be using JDK 7, the newly available Objects class is the obvious (at least to me) choice for implementing the “common” Java object ...

I'm currently beating my head against the following problem, and I could use a point in the right direction.<BR><BR>For my current task, I'm required to generate an implementation for clone(), equals( ...