翻阅String类源代码发现几个有趣的地方
1、看以下代码 Stirng类的hashcode 方法
/** * Returns a canonical representation for the string object. * <p> * A pool of strings, initially empty, is maintained privately by the * class <code>String</code>. * <p> * When the intern method is invoked, if the pool already contains a * string equal to this <code>String</code> object as determined by * the {@link #equals(Object)} method, then the string from the pool is * returned. Otherwise, this <code>String</code> object is added to the * pool and a reference to this <code>String</code> object is returned. * <p> * It follows that for any two strings <code>s</code> and <code>t</code>, * <code>s.intern() == t.intern()</code> is <code>true</code> * if and only if <code>s.equals(t)</code> is <code>true</code>. * <p> * All literal strings and string-valued constant expressions are * interned. String literals are defined in §3.10.5 of the * <a href="http://java.sun.com/docs/books/jls/html/">Java Language * Specification</a> * * @return a string that has the same contents as this string, but is * guaranteed to be from a pool of unique strings. */ public native String intern();