com.tesora.dve.distribution.compare.ComparatorCache.java Source code

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Here is the source code for com.tesora.dve.distribution.compare.ComparatorCache.java

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package com.tesora.dve.distribution.compare;

/*
 * #%L
 * Tesora Inc.
 * Database Virtualization Engine
 * %%
 * Copyright (C) 2011 - 2014 Tesora Inc.
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 * 
 * This program 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 Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 * #L%
 */

import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.lang.StringUtils;

import com.fasterxml.uuid.impl.UUIDUtil;
import com.google.common.primitives.SignedBytes;

public class ComparatorCache {

    public static final String DEFAULT_UUID_COMPARATOR = "com.tesora.dve.comparator.UUIDComparator";

    @SuppressWarnings("rawtypes")
    private static Map<String, Comparator> comparators = new HashMap<String, Comparator>();

    @SuppressWarnings("rawtypes")
    public static final Comparator<Comparable> DEFAULT_COMPARATOR = new Comparator<Comparable>() {
        @SuppressWarnings("unchecked")
        @Override
        public int compare(Comparable arg0, Comparable arg1) {
            return arg0.compareTo(arg1);
        }
    };

    public static final Comparator<Object> BINARY_COMPARATOR = new Comparator<Object>() {
        @Override
        public int compare(Object o1, Object o2) {
            return SignedBytes.lexicographicalComparator().compare((byte[]) o1, (byte[]) o2);
        }
    };

    public static final Comparator<Object> UUID_COMPARATOR = new Comparator<Object>() {
        @Override
        public int compare(Object o1, Object o2) {
            String s1 = (o1 instanceof String) ? (String) o1 : new String((byte[]) o1);
            String s2 = (o2 instanceof String) ? (String) o2 : new String((byte[]) o2);
            return UUIDUtil.uuid(s1).compareTo(UUIDUtil.uuid(s2));
        }
    };

    protected ComparatorCache() {
    }

    @SuppressWarnings("rawtypes")
    public static Comparator get(String comparatorClassName) {
        if (comparators.containsKey(comparatorClassName)) {
            return comparators.get(comparatorClassName);
        } else {
            return DEFAULT_COMPARATOR;
        }
    }

    public static void add(String comparatorClassName) {
        // For now hard code our implementation of UUID to this comparator class name
        if (!comparators.containsKey(comparatorClassName)) {
            if (StringUtils.equalsIgnoreCase(comparatorClassName, DEFAULT_UUID_COMPARATOR)) {
                comparators.put(comparatorClassName, UUID_COMPARATOR);
            }
        }

        // try to dynamically load the jar file...
        //      try {
        //         if (!managers.containsKey(comparator)) {
        //            Class<?> theClass = null;
        //            try {
        //               theClass = Class.forName(comparator);
        //            } catch (Exception e) {
        //               // new jar? look for new ones
        //               Collection<File> files = FileUtils.listFiles(new File("D:\\Eclipse\\workspace\\general\\UUIDComparator\\target"),
        //                         new String[] {"jar"},
        //                         false);
        //               List<URL> urls = new ArrayList<URL>();
        //               for(File file : files) {
        //                    URL u = file.toURI().toURL();
        //                    urls.add(u);
        //               }
        ////                 URLClassLoader sysloader = (URLClassLoader) ClassLoader.getSystemClassLoader();
        ////                 theClass = sysloader.loadClass(comparator);
        //               URLClassLoader child = new URLClassLoader(urls.toArray(new URL[urls.size()]), ComparisonManager.class.getClassLoader());
        //               Class classToLoad = Class.forName (comparator, true, child);
        //               Comparator c = (Comparator)theClass.newInstance();
        //               managers.put(comparator, c);
        //            }
        //            
        //         }
        //      } catch (Exception e) {
        //         e.printStackTrace();
        //      }
    }
}