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

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Here is the source code for de.unentscheidbar.validation.builtin.EmailAddressValidator.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 java.util.regex.Pattern;

import javax.annotation.concurrent.Immutable;

import org.apache.commons.lang3.StringUtils;

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

/**
 *
 * @author Tim Boudreau
 * @author Daniel Huss
 */
@Immutable
public final class EmailAddressValidator extends EmptyStringAcceptingValidator {

    private static final long serialVersionUID = Validation.VERSION;

    public static enum Id implements ValidationMessage.Id {
        NO_AT_SYMBOL, EMAIL_MISSING_HOST, EMAIL_HAS_MORE_THAN_ONE_AT_SYMBOL, EMAIL_MISSING_NAME, ADDRESS_PROBABLY_TOO_LONG, EMAIL_HOST_IS_IP, EMAIL_NAME_INVALID;
    }

    private static final EmailAddressValidator INSTANCE = new EmailAddressValidator();

    public static EmailAddressValidator instance() {

        return INSTANCE;
    }

    private EmailAddressValidator() {

        super();
    }

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

        String[] nameAndHost = StringUtils.splitPreserveAllTokens(model, '@');
        switch (nameAndHost.length) {
        case 0:
            // String is empty - cannot happen in validateNonEmptyString
            throw new AssertionError();
        case 1:
            problems.add(Id.NO_AT_SYMBOL, model);
            break;
        case 2:
            validateLocalPart(nameAndHost[0], model, problems);
            validateGlobalPart(nameAndHost[1], model, problems);
            break;
        default:
            assert nameAndHost.length > 2;
            problems.add(Id.EMAIL_HAS_MORE_THAN_ONE_AT_SYMBOL, model);
            break;
        }

    }

    private void validateGlobalPart(String globalPart, String address, ValidationResult problems) {

        if (globalPart.isEmpty()) {
            problems.add(Id.EMAIL_MISSING_HOST, address);
        } else if (Ipv4AddressValidator.singleAddress().wouldAcceptWithout(Severity.ERROR, globalPart)) {
            problems.add(Id.EMAIL_HOST_IS_IP);
        } else {
            HostNameValidator.instance().validate(problems, globalPart);
        }
    }

    private static final String SPECIAL_CHAR_EXP = "[-\\._+]";

    private static final Pattern SPECIAL_CHAR = Pattern.compile(SPECIAL_CHAR_EXP);

    private static final Pattern REPEAT_SPECIAL_CHAR = Pattern.compile("(" + SPECIAL_CHAR_EXP + ")\\1");

    private static final Pattern LOCAL_PART = Pattern.compile("(\\w|" + SPECIAL_CHAR_EXP + ")+");

    private void validateLocalPart(String localPart, String address, ValidationResult problems) {

        if (localPart.isEmpty()) {
            problems.add(Id.EMAIL_MISSING_NAME, address);
            return;
        }

        if (localPart.length() > 64) {
            problems.add(Id.ADDRESS_PROBABLY_TOO_LONG, Severity.WARNING, address);
        }

        assert localPart.length() > 0;
        String firstChar = localPart.substring(localPart.length() - 1);
        String lastChar = localPart.substring(0, 1);
        if (
        /* Only alphanumeric and certain special characters, no quoted strings */
        !LOCAL_PART.matcher(localPart).matches() ||

        /* No special characters at beginning or end */
                SPECIAL_CHAR.matcher(firstChar).matches() || SPECIAL_CHAR.matcher(lastChar).matches()

                /* No repetition of special characters */
                || REPEAT_SPECIAL_CHAR.matcher(localPart).find()) {
            problems.add(Id.EMAIL_NAME_INVALID, address);
        }
    }
}