Thread: Casting java.lang.String to a custom class

Matrix's dialogue system to get dialogues is as follows:

Put a dialogue like this: handledDialogues.put("Bob", (Class<Dialogue>) Bob.class.getCanonicalName());

So I said to myself, why not add them all automatically by file location?

I did this:

		for (File file : new File("bin/com/rs/game/player/dialogues/impl").listFiles()) {
				Class<Dialogue> dialogue = (Class<Dialogue>) Class.forName(file.getName().replaceAll(".class", "").getClass().getCanonicalName());
				if (!handledDialogues.containsKey(dialogue)) {
					handledDialogues.put(file.getName().replaceAll(".class", ""), dialogue);
					System.out.println("put " + file.getName());
				}
			}

And now the dialogues in the impl folder are not loading and this error is printed:

java.lang.ClassCastException: java.lang.String cannot be cast to com.rs.game.player.dialogues.Dialogue
	at com.rs.game.player.dialogues.DialogueHandler.getDialogue(DialogueHandler.java:208)
	at com.rs.game.player.DialogueManager.startDialogue(DialogueManager.java:20)
	at com.rs.networking.decoders.handlers.NPCHandler$1.run(NPCHandler.java:96)
	at com.rs.game.player.CoordsEvent.processEvent(CoordsEvent.java:46)
	at com.rs.game.player.Player.processEntity(Player.java:543)
	at com.rs.cores.WorldThread.run(WorldThread.java:34)

On line:
return classD.newInstance();

	public static final Dialogue getDialogue(Object key) {
		if (key instanceof Dialogue)
			return (Dialogue) key;
		Class<Dialogue> classD = handledDialogues.get(key);
		if (classD == null)
			return null;
		try {
			return classD.newInstance();
		} catch (Throwable e) {
			Logger.handle(e);
		}
		return null;
	}

What does the newInstance() method return?

What variable has a String value?

Can you post the code for the newInstance() method to show what it returns?

Or can you post a small complete program that compiles, executes and shows the problem?

Can you post the code? Your link does not show the code. It points to an error message.

Can you post the code for the newInstance() method?

Can you post a small complete program that compiles, executes and shows the problem?

The culprit line is here. (PS aren't you from rune-server?)

Class<Dialogue> dialogue = (Class<Dialogue>) Class.forName(file.getName().replaceAll(".class", "").getClass().getCanonicalName());

`file.getName().replaceAll(...)` is a String object, so calling `getClass()` returns String.class. `String.class.getCanonicalName()` will then be "java.lang.String.class", which (after removing the .class extension), when passed through Class.forName(), will return String.class once again... heh. Maybe you should write your code a bit cleaner so you notice simple mistakes like this with ease.

EDIT: To clarify, what you probably want is:

String name = file.getName();
name = name.substring(0, name.length() - 6);
Class<? extends Dialogue> clazz = Class.forName("com.rs.game.player.dialogues.impl." + name).asSubclass(Dialogue.class);
if (!handledDialogues.containsKey(name)) {
  handledDialogues.put(name, clazz);
}