de.unentscheidbar.validation.builtin.HostNameValidator.java Source code

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Here is the source code for de.unentscheidbar.validation.builtin.HostNameValidator.java

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/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2009 Sun Microsystems, Inc. All rights reserved. Portions Copyrighted 2012 Daniel
 * Huss.
 * 
 * The contents of this file are subject to the terms of either the GNU General Public License
 * Version 2 only ("GPL") or the Common Development and Distribution License("CDDL") (collectively,
 * the "License"). You may not use this file except in compliance with the License. You can obtain a
 * copy of the License at http://www.netbeans.org/cddl-gplv2.html or nbbuild/licenses/CDDL-GPL-2-CP.
 * See the License for the specific language governing permissions and limitations under the
 * License. When distributing the software, include this License Header Notice in each file and
 * include the License file at nbbuild/licenses/CDDL-GPL-2-CP. Sun designates this particular file
 * as subject to the "Classpath" exception as provided by Sun in the GPL Version 2 section of the
 * License file that accompanied this code. If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyrighted [year] [name of copyright owner]"
 * 
 * Contributor(s):
 * 
 * The Original Software is NetBeans. The Initial Developer of the Original Software is Sun
 * Microsystems, Inc. Portions Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * If you wish your version of this file to be governed by only the CDDL or only the GPL Version 2,
 * indicate your decision by adding "[Contributor] elects to include this software in this
 * distribution under the [CDDL or GPL Version 2] license." If you do not indicate a single choice
 * of license, a recipient has the option to distribute your version of this file under either the
 * CDDL, the GPL Version 2 or to extend the choice of license to its licensees as provided above.
 * However, if you add GPL Version 2 code and therefore, elected the GPL Version 2 license, then the
 * option applies only if the new code is made subject to such option by the copyright holder.
 */
package de.unentscheidbar.validation.builtin;

import javax.annotation.concurrent.Immutable;

import org.apache.commons.lang3.StringUtils;

import de.unentscheidbar.validation.ValidationMessage;
import de.unentscheidbar.validation.ValidationResult;
import de.unentscheidbar.validation.swing.Validation;

/**
 * Only accepts strings that are valid host names as specified in <a
 * href="http://www.ietf.org/rfc/rfc1123.txt">RFC 1123</a>.
 * 
 * @author Tim Boudreau
 * @author Daniel Huss
 */
@Immutable
public final class HostNameValidator extends EmptyStringAcceptingValidator {

    private static final long serialVersionUID = Validation.VERSION;

    private static final String VALID_LABEL_CHARS = validLabelChars();

    private static final HostNameValidator INSTANCE = new HostNameValidator();

    public static HostNameValidator instance() {

        return INSTANCE;
    }

    private HostNameValidator() {

        super();
    }

    private static String validLabelChars() {

        StringBuilder b = new StringBuilder("-");
        for (char c = 'a'; c <= 'z'; c++) {
            b.append(c);
            b.append(Character.toUpperCase(c));
        }
        for (char c = '0'; c <= '9'; c++) {
            b.append(c);
        }
        return b.toString();
    }

    public static enum Id implements ValidationMessage.Id {
        HOST_STARTS_WITH_DOT, HOST_STARTS_OR_ENDS_WITH_HYPHEN, LABEL_TOO_LONG, LABEL_EMPTY, BAD_CHAR_IN_HOSTNAME, HOST_TOO_LONG;
    }

    @Override
    protected void validateNonEmptyString(ValidationResult problems, String model) {

        /*
         * #1 Host names must not start with a dot.
         */
        if (model.startsWith(".")) {
            problems.add(Id.HOST_STARTS_WITH_DOT, model);
            return;
        }

        /*
         * #2 Host names must not start or end with a hyphen.
         */
        if (model.endsWith("-") || model.startsWith("-")) {
            problems.add(Id.HOST_STARTS_OR_ENDS_WITH_HYPHEN, model);
        }

        /*
         * #3 The complete host name must not be longer than 255 characters and does not permit
         * leading or trailing whitespace.
         */
        MayNotContainWhitespaceValidator.instance().validate(problems, model);
        if (model.length() > 255) {
            problems.add(Id.HOST_TOO_LONG);
        }

        /*
         * #4 Each label must consist of 1-63 characters. Only ASCII a-z, 0-9, period and hypen are
         * allowed.
         */
        String[] parts = StringUtils.splitPreserveAllTokens(model, '.');
        for (int i = 0; i < parts.length; i++) {
            validateLabel(problems, parts[i]);
        }
    }

    private void validateLabel(ValidationResult problems, String label) {

        if (label.length() > 63) {
            problems.add(Id.LABEL_TOO_LONG, label);
        } else if (label.length() == 0) {
            problems.add(Id.LABEL_EMPTY, label);
        }
        int idx = StringUtils.indexOfAnyBut(label, VALID_LABEL_CHARS);
        if (idx != -1)
            problems.add(Id.BAD_CHAR_IN_HOSTNAME, String.valueOf(label.charAt(idx)));
    }
}