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	/*
	* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package sun.security.util;

	import javax.security.auth.callback.Callback;
	import javax.security.auth.callback.CallbackHandler;
	import javax.security.auth.callback.ConfirmationCallback;
	import javax.security.auth.callback.NameCallback;
	import javax.security.auth.callback.PasswordCallback;
	import javax.security.auth.callback.TextOutputCallback;
	import javax.security.auth.callback.UnsupportedCallbackException;

	import java.io.BufferedReader;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InputStreamReader;

	/**
	* A {@code CallbackHandler} that prompts and reads from the command line
	* for answers to authentication questions.
	*/
	public class ConsoleCallbackHandler implements CallbackHandler {

	/**
	* Creates a callback handler that prompts and reads from the
	* command line for answers to authentication questions.
	*/
	public ConsoleCallbackHandler() { }

	/**
	* 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
	*/
	public void handle(Callback[] callbacks)
	throws IOException, UnsupportedCallbackException
	{
	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, pc.isEchoOn()));

	} 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);
	}
	}

	/* Reads a line of input */
	private String readLine() throws IOException {
	String result = new BufferedReader
	(new InputStreamReader(System.in)).readLine();
	if (result == null) {
	throw new IOException("Cannot read from System.in");
	}
	return result;
	}

	private void doConfirmation(ConfirmationCallback confirmation)
	throws IOException, UnsupportedCallbackException
	{
	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] = new OptionInfo(optionStrings[i], 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);
	}
	}

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