看看Java API中的说法，也许会明白些。public String intern()
Returns a canonical representation for the string object.
A pool of strings, initially empty, is maintained privately by the class String. When the intern method is invoked, if the pool already contains a string equal to this String object as determined by the equals(Object) method, then the string from the pool is returned. Otherwise, this String object is added to the pool and a reference to this String object is returned. It follows that for any two strings s and t, s.intern() == t.intern() is true if and only if s.equals(t) is true.
Returns a canonical representation for the string object.
A pool of strings, initially empty, is maintained privately by the class String. When the intern method is invoked, if the pool already contains a string equal to this String object as determined by the equals(Object) method, then the string from the pool is returned. Otherwise, this String object is added to the pool and a reference to this String object is returned. It follows that for any two strings s and t, s.intern() == t.intern() is true if and only if s.equals(t) is true.
"hello"本身会放入字符串常量池
intern()好像就是用来返回该字符串在常量池中的引用(如果有的话)有人说可以加快字符串比较的速度，不过我在现实中从来没用过 :P