org.sakaiproject.tool.assessment.util.BeanSortComparator.java Source code

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Here is the source code for org.sakaiproject.tool.assessment.util.BeanSortComparator.java

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/**********************************************************************************
 * $URL$
 * $Id$
 ***********************************************************************************
 *
 * Copyright (c) 2005, 2006, 2008, 2009 The Sakai Foundation
 *
 * Licensed under the Educational Community License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.opensource.org/licenses/ECL-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 **********************************************************************************/

package org.sakaiproject.tool.assessment.util;

import java.io.Serializable;

import java.util.Comparator;
import java.util.Map;
import java.util.HashMap;
import java.text.Collator;
import java.text.ParseException;
import java.text.RuleBasedCollator;

import org.apache.commons.beanutils.BeanUtils;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * DOCUMENTATION PENDING
 *
 * @author $author$
 * @version $Id$
 */
public class BeanSortComparator implements Comparator {
    private static Log log = LogFactory.getLog(BeanSortComparator.class);
    private String propertyName;

    /**
     * The only public constructor.  Requires a valid property name for a a Java
     * Bean as a sole parameter.
     *
     * @param propertyName the property name for Java Bean to sort by
     */
    public BeanSortComparator(String propertyName) {
        this.propertyName = propertyName;
    }

    /**
     * Creates a new BeanSortComparator object.
     */
    protected BeanSortComparator() {
    };

    /**
     * standard compare method
     *
     * @param o1 object
     * @param o2 object
     *
     * @return lt, eq, gt zero depending on whether o1 lt, eq, gt o2
     */
    public int compare(Object o1, Object o2) {
        int result = 0;
        Map m1 = describeBean(o1);
        Map m2 = describeBean(o2);
        String s1 = (String) m1.get(propertyName);
        String s2 = (String) m2.get(propertyName);

        result = subCompare(s1, s2);

        // If students have the same last name, then we need to compare their first name
        if (result == 0 && "lastName".equals(propertyName)) {
            String firstName1 = (String) m1.get("firstName");
            String firstName2 = (String) m2.get("firstName");
            result = subCompare(firstName1, firstName2);
        }
        // Take out tags
        return result;
    }

    private int subCompare(String s1, String s2) {
        //we do not want to use null values for sorting
        if (s1 == null) {
            s1 = "";
        }

        if (s2 == null) {
            s2 = "";
        }

        // Deal with n/a case
        if (s1.toLowerCase().startsWith("n/a") && !s2.toLowerCase().startsWith("n/a"))
            return 1;

        if (s2.toLowerCase().startsWith("n/a") && !s1.toLowerCase().startsWith("n/a"))
            return -1;

        String finalS1 = s1.replaceAll("<.*?>", "");
        String finalS2 = s2.replaceAll("<.*?>", "");
        RuleBasedCollator collator_ini = (RuleBasedCollator) Collator.getInstance();
        try {
            RuleBasedCollator collator = new RuleBasedCollator(
                    collator_ini.getRules().replaceAll("<'\u005f'", "<' '<'\u005f'"));
            return collator.compare(finalS1.toLowerCase(), finalS2.toLowerCase());
        } catch (ParseException e) {
        }
        return Collator.getInstance().compare(finalS1.toLowerCase(), finalS2.toLowerCase());
    }

    /**
     * protected utility method to wrap BeanUtils
     *
     * @param o DOCUMENTATION PENDING
     *
     * @return DOCUMENTATION PENDING
     *
     * @throws java.lang.UnsupportedOperationException DOCUMENTATION PENDING
     */
    protected Map describeBean(Object o) {
        Map m = null;

        try {
            m = BeanUtils.describe((Serializable) o);
        } catch (Throwable t) {
            log.debug("Caught error in BeanUtils.describe(): " + t.getMessage());
            t.printStackTrace();

            throw new java.lang.UnsupportedOperationException(
                    "Invalid describeBean. Objects may not be Java Beans.  " + t);

        }

        return m;
    }
}