Java example source code file (Negotiator.java)

This example Java source code file (Negotiator.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

assertionerror, class, classnotfoundexception, constructor, ioexception, negotiateauthentication, negotiator, platformlogger, reflection, reflectiveoperationexception, throwable

The Negotiator.java Java example source code

/*
 * Copyright (c) 2009, 2013, 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.net.www.protocol.http;

import java.io.IOException;
import java.lang.reflect.Constructor;
import sun.util.logging.PlatformLogger;

/**
 * This abstract class is a bridge to connect NegotiteAuthentication and
 * NegotiatorImpl, so that JAAS and JGSS calls can be made
 */
public abstract class Negotiator {
    static Negotiator getNegotiator(HttpCallerInfo hci) {

        // These lines are equivalent to
        // return new NegotiatorImpl(hci);
        // The current implementation will make sure NegotiatorImpl is not
        // directly referenced when compiling, thus smooth the way of building
        // the J2SE platform where HttpURLConnection is a bootstrap class.
        //
        // Makes NegotiatorImpl, and the security classes it references, a
        // runtime dependency rather than a static one.

        Class<?> clazz;
        Constructor<?> c;
        try {
            clazz = Class.forName("sun.net.www.protocol.http.spnego.NegotiatorImpl", true, null);
            c = clazz.getConstructor(HttpCallerInfo.class);
        } catch (ClassNotFoundException cnfe) {
            finest(cnfe);
            return null;
        } catch (ReflectiveOperationException roe) {
            // if the class is there then something seriously wrong if
            // the constructor is not.
            throw new AssertionError(roe);
        }

        try {
            return (Negotiator) (c.newInstance(hci));
        } catch (ReflectiveOperationException roe) {
            finest(roe);
            Throwable t = roe.getCause();
            if (t != null && t instanceof Exception)
                finest((Exception)t);
            return null;
        }
    }

    public abstract byte[] firstToken() throws IOException;

    public abstract byte[] nextToken(byte[] in) throws IOException;

    private static void finest(Exception e) {
        PlatformLogger logger = HttpURLConnection.getHttpLogger();
        if (logger.isLoggable(PlatformLogger.Level.FINEST)) {
            logger.finest("NegotiateAuthentication: " + e);
        }
    }
}