FileDocCategorySizeDatePackage
TextCallbackHandler.javaAPI DocJava SE 5 API6610Fri Aug 26 14:56:14 BST 2005com.sun.security.auth.callback

TextCallbackHandler

public class TextCallbackHandler extends Object implements CallbackHandler

Prompts and reads from the command line for answers to authentication questions. This can be used by a JAAS application to instantiate a CallbackHandler

see
javax.security.auth.callback

Fields Summary
Constructors Summary
public TextCallbackHandler()

Creates a callback handler that prompts and reads from the command line for answers to authentication questions. This can be used by JAAS applications to instantiate a CallbackHandler.
Methods Summary
private voiddoConfirmation(javax.security.auth.callback.ConfirmationCallback confirmation)

	String prefix;
	int messageType = confirmation.getMessageType();
	switch (messageType) {
	case ConfirmationCallback.WARNING:
	    prefix =  "Warning: ";
	    break;
	case ConfirmationCallback.ERROR:
	    prefix = "Error: ";
	    break;
	case ConfirmationCallback.INFORMATION:
	    prefix = "";
	    break;
	default:
	    throw new UnsupportedCallbackException(
		confirmation, "Unrecognized message type: " + messageType);
	}

	class OptionInfo {
	    String name;
	    int value;
	    OptionInfo(String name, int value) {
		this.name = name;
		this.value = value;
	    }
	}

	OptionInfo[] options;
	int optionType = confirmation.getOptionType();
	switch (optionType) {
	case ConfirmationCallback.YES_NO_OPTION:
	    options = new OptionInfo[] {
		new OptionInfo("Yes", ConfirmationCallback.YES),
		new OptionInfo("No", ConfirmationCallback.NO)
	    };
	    break;
	case ConfirmationCallback.YES_NO_CANCEL_OPTION:
	    options = new OptionInfo[] {
		new OptionInfo("Yes", ConfirmationCallback.YES),
		new OptionInfo("No", ConfirmationCallback.NO),
		new OptionInfo("Cancel", ConfirmationCallback.CANCEL)
	    };
	    break;
	case ConfirmationCallback.OK_CANCEL_OPTION:
	    options = new OptionInfo[] {
		new OptionInfo("OK", ConfirmationCallback.OK),
		new OptionInfo("Cancel", ConfirmationCallback.CANCEL)
	    };
	    break;
	case ConfirmationCallback.UNSPECIFIED_OPTION:
	    String[] optionStrings = confirmation.getOptions();
	    options = new OptionInfo[optionStrings.length];
	    for (int i = 0; i < options.length; i++) {
		options[i].value = i;
	    }
	    break;
	default:
	    throw new UnsupportedCallbackException(
		confirmation, "Unrecognized option type: " + optionType);
	}

	int defaultOption = confirmation.getDefaultOption();

	String prompt = confirmation.getPrompt();
	if (prompt == null) {
	    prompt = "";
	}
	prompt = prefix + prompt;
	if (!prompt.equals("")) {
	    System.err.println(prompt);
	}

	for (int i = 0; i < options.length; i++) {
	    if (optionType == ConfirmationCallback.UNSPECIFIED_OPTION) {
		// defaultOption is an index into the options array
		System.err.println(
		    i + ". " + options[i].name +
		    (i == defaultOption ? " [default]" : ""));
	    } else {
		// defaultOption is an option value
		System.err.println(
		    i + ". " + options[i].name +
		    (options[i].value == defaultOption ? " [default]" : ""));
	    }
	}
	System.err.print("Enter a number: ");
	System.err.flush();
	int result;
	try {
	    result = Integer.parseInt(readLine());
	    if (result < 0 || result > (options.length - 1)) {
		result = defaultOption;
	    }
	    result = options[result].value;
	} catch (NumberFormatException e) {
	    result = defaultOption;
	}

	confirmation.setSelectedIndex(result);
public voidhandle(javax.security.auth.callback.Callback[] callbacks)
Handles the specified set of callbacks.

param
callbacks the callbacks to handle
throws
IOException if an input or output error occurs.
throws
UnsupportedCallbackException if the callback is not an instance of NameCallback or PasswordCallback

	ConfirmationCallback confirmation = null;

	for (int i = 0; i < callbacks.length; i++) {
	    if (callbacks[i] instanceof TextOutputCallback) {
		TextOutputCallback tc = (TextOutputCallback) callbacks[i];

		String text;
		switch (tc.getMessageType()) {
		case TextOutputCallback.INFORMATION:
		    text = "";
		    break;
		case TextOutputCallback.WARNING:
		    text = "Warning: ";
		    break;
		case TextOutputCallback.ERROR:
		    text = "Error: ";
		    break;
		default:
		    throw new UnsupportedCallbackException(
			callbacks[i], "Unrecognized message type");
		}

		String message = tc.getMessage();
		if (message != null) {
		    text += message;
		}
		if (text != null) {
		    System.err.println(text);
		}
		
	    } else if (callbacks[i] instanceof NameCallback) {
 		NameCallback nc = (NameCallback) callbacks[i];

		if (nc.getDefaultName() == null) {
 		    System.err.print(nc.getPrompt());
		} else {
 		    System.err.print(nc.getPrompt() +
				" [" + nc.getDefaultName() + "] ");
		}
 		System.err.flush();

		String result = readLine();
		if (result.equals("")) {
		    result = nc.getDefaultName();
		}

		nc.setName(result);
 
 	    } else if (callbacks[i] instanceof PasswordCallback) {
 		PasswordCallback pc = (PasswordCallback) callbacks[i];

 		System.err.print(pc.getPrompt());
 		System.err.flush();

 		pc.setPassword(Password.readPassword(System.in));
  
	    } else if (callbacks[i] instanceof ConfirmationCallback) {
		confirmation = (ConfirmationCallback) callbacks[i];

 	    } else {
 		throw new UnsupportedCallbackException(
		    callbacks[i], "Unrecognized Callback");
 	    }
	}
	    
	/* Do the confirmation callback last. */
	if (confirmation != null) {
	    doConfirmation(confirmation);
	}
private java.lang.StringreadLine()

	return new BufferedReader
	    (new InputStreamReader(System.in)).readLine();