ExternExampleEvolvedClasspublic class ExternExampleEvolvedClass extends Object | This is a continuation of the Externalizable Persistence Example.
This file contains the evolved version of the ExternVersioningClass.
Of course, normally, the evolved class would actually take place of the
original class but we just keep both of them to demonstrate the evolution
For information on how to run, see file ExternExampleOriginalClass.java |
| Methods Summary |
|---|
| public static void | main(java.lang.String[] args)There are two options: either a user can serialize an object or
deserialize it. (using the -s or -d flag). These options allow
for the demonstration of bidirection readability and writeability
between the original and the evolved class. In other words,
one can serialize an object here and deserialize it with the evolved
class or vice versa.
boolean serialize = false;
boolean deserialize = false;
ExternVersioningClass wobj = new ExternVersioningClass
(1, "evolvedclass", true, 1.23);
ExternVersioningClass robj = null;
/*
* see if we are serializing or deserializing.
* The ability to deserialize or serialize allows
* us to see the bidirectional readability and writeability
*/
if (args.length == 1) {
if (args[0].equals("-d")) {
deserialize = true;
} else if (args[0].equals("-s")) {
serialize = true;
} else {
usage();
System.exit(0);
}
} else {
usage();
System.exit(0);
}
/*
* serialize, if that's the chosen option
*/
if (serialize) {
try {
FileOutputStream fo = new FileOutputStream("evolve.tmp");
ObjectOutputStream so = new ObjectOutputStream(fo);
so.writeObject(wobj);
so.flush();
} catch (Exception e) {
System.out.println(e);
System.exit(1);
}
}
/*
* deserialize, if that's the chosen option
*/
if (deserialize) {
try {
FileInputStream fi = new FileInputStream("evolve.tmp");
ObjectInputStream si = new ObjectInputStream(fi);
robj = (ExternVersioningClass) si.readObject();
} catch (Exception e) {
System.out.println(e);
System.exit(1);
}
}
| | static void | usage()Prints out the usage
System.out.println("Usage:");
System.out.println(" -s (in order to serialize)");
System.out.println(" -d (in order to deserialize)");
|
|
