UniquePropertiesCheck.java

////////////////////////////////////////////////////////////////////////////////

// checkstyle: Checks Java source code for adherence to a set of rules.

// Copyright (C) 2001-2017 the original author or authors.

//

// This library is free software; you can redistribute it and/or

// modify it under the terms of the GNU Lesser General Public

// License as published by the Free Software Foundation; either

// version 2.1 of the License, or (at your option) any later version.

//

// This library 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

// Lesser General Public License for more details.

//

// You should have received a copy of the GNU Lesser General Public

// License along with this library; if not, write to the Free Software

// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

////////////////////////////////////////////////////////////////////////////////

package com.puppycrawl.tools.checkstyle.checks;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.util.Properties;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import com.google.common.collect.HashMultiset;

import com.google.common.collect.ImmutableMultiset;

import com.google.common.collect.Multiset;

import com.google.common.collect.Multiset.Entry;

import com.google.common.io.Closeables;

import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;

import com.puppycrawl.tools.checkstyle.api.FileText;

/**

 * Checks the uniqueness of property keys (left from equal sign) in the

 * properties file.

 *

 * @author Pavel Baranchikov

 */

public class UniquePropertiesCheck extends AbstractFileSetCheck {

    /**

     * Localization key for check violation.

     */

    public static final String MSG_KEY = "properties.duplicate.property";

    /**

     * Localization key for IO exception occurred on file open.

     */

    public static final String MSG_IO_EXCEPTION_KEY = "unable.open.cause";

    /**

     * Pattern matching single space.

     */

    /**

     * Construct the check with default values.

     */

    @Override

    protected void processFiltered(File file, FileText fileText) {

        try {

        }

        }

        finally {

            // Number of occurrences is number of duplications + 1

    /**

     * Method returns line number the key is detected in the checked properties

     * files first.

     *

     * @param fileText

     *            {@link FileText} object contains the lines to process

     * @param keyName

     *            key name to look for

     * @return line number of first occurrence. If no key found in properties

     *         file, 0 is returned

     */

    private static int getLineNumber(FileText fileText, String keyName) {

            }

        }

        // -1 as check seeks for the first duplicate occurance in file,

        // so it cannot be the last line.

        }

    }

    /**

     * Method returns regular expression pattern given key name.

     *

     * @param keyName

     *            key name to look for

     * @return regular expression pattern given key name

     */

    private static Pattern getKeyPattern(String keyName) {

    }

    /**

     * Properties subclass to store duplicated property keys in a separate map.

     *

     * @author Pavel Baranchikov

     * @noinspection ClassExtendsConcreteCollection, SerializableHasSerializationMethods

     */

    private static class UniqueProperties extends Properties {

        private static final long serialVersionUID = 1L;

        /**

         * Multiset, holding duplicated keys. Keys are added here only if they

         * already exist in Properties' inner map.

         */

        private final Multiset<String> duplicatedKeys = HashMultiset

                .create();

        /**

         * Puts the value into properties by the key specified.

         * @noinspection UseOfPropertiesAsHashtable

         */

        @Override

        public synchronized Object put(Object key, Object value) {

            final Object oldValue = super.put(key, value);

            if (oldValue != null && key instanceof String) {

                final String keyString = (String) key;

                duplicatedKeys.add(keyString);

            }

            return oldValue;

        }

        /**

         * Retrieves a collections of duplicated properties keys.

         *

         * @return A collection of duplicated keys.

         */

        public Multiset<String> getDuplicatedKeys() {

            return ImmutableMultiset.copyOf(duplicatedKeys);

        }

    }

}

Mutations