org.beangle.commons.comparators.PropertyComparator.java Source code

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Here is the source code for org.beangle.commons.comparators.PropertyComparator.java

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/* Copyright c 2005-2012.
 * Licensed under GNU  LESSER General Public License, Version 3.
 * http://www.gnu.org/licenses
 */
package org.beangle.commons.comparators;

import java.util.Comparator;

import org.apache.commons.beanutils.NestedNullException;
import org.apache.commons.beanutils.PropertyUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.math.NumberUtils;

/**
 * <br>
 * 
 * @author chaostone
 */
public class PropertyComparator<T> implements Comparator<T> {

    private String cmpWhat;

    private int index = -1;

    private boolean asc;

    // ??null????null??
    private boolean nullFirst = true;

    @SuppressWarnings("rawtypes")
    private Comparator comparator;

    private StringComparator stringComparator;

    /**
     * new OrderedBeanComparator("id") or<br>
     * new OrderedBeanComparator("name desc"); new
     * OrderedBeanComparator("[0].name desc");
     * 
     * @param cmpStr
     */
    public PropertyComparator(final String cmpStr) {
        if (StringUtils.isEmpty(cmpStr)) {
            return;
        }

        if (StringUtils.contains(cmpStr, ',')) {
            throw new RuntimeException(
                    "PropertyComparator don't suport comma based order by." + " Use MultiPropertyComparator ");
        }
        cmpWhat = cmpStr.trim();
        // ?[]?
        if ('[' == cmpWhat.charAt(0)) {
            index = NumberUtils.toInt(StringUtils.substringBetween(cmpWhat, "[", "]"));
            cmpWhat = StringUtils.substringAfter(cmpWhat, "]");
            if (cmpWhat.length() > 0 && '.' == cmpWhat.charAt(0)) {
                cmpWhat = cmpWhat.substring(1);
            }
        }
        // ??
        asc = true;
        if (StringUtils.contains(cmpWhat, ' ')) {
            if (StringUtils.contains(cmpWhat, " desc")) {
                asc = false;
            }
            cmpWhat = cmpWhat.substring(0, cmpWhat.indexOf(' '));
        }
        stringComparator = new CollatorStringComparator(asc);
    }

    public PropertyComparator(final String cmpWhat, final boolean asc) {
        this(cmpWhat + " " + (asc ? "" : "desc"));
    }

    @SuppressWarnings("unchecked")
    public int compare(Object arg0, Object arg1) {
        Object what0 = null;
        Object what1 = null;
        // ?
        if (index > -1) {
            arg0 = ((Object[]) arg0)[index];
            arg1 = ((Object[]) arg1)[index];
            if (StringUtils.isEmpty(cmpWhat)) {
                what0 = arg0;
                what1 = arg1;
            }
        }
        if (StringUtils.isNotEmpty(cmpWhat)) {
            try {
                what0 = PropertyUtils.getProperty(arg0, cmpWhat);
            } catch (NestedNullException e) {
                what0 = null;
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
            try {
                what1 = PropertyUtils.getProperty(arg1, cmpWhat);
            } catch (NestedNullException e) {
                what1 = null;
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }

        if (what0 == null && null == what1) {
            return 0;
        }

        // 
        if (null == comparator) {
            if (what0 == null && null != what1) {
                return asc && nullFirst ? -1 : 1;
            }

            if (what0 != null && null == what1) {
                return asc && nullFirst ? 1 : -1;
            }
            // 
            if (what0 instanceof String || what1 instanceof String) {
                return stringComparator.compare(what0.toString(), what1.toString());
            } else {
                if (asc) {
                    return ((Comparable<Object>) what0).compareTo(what1);
                } else {
                    return ((Comparable<Object>) what1).compareTo(what0);
                }
            }
        } else {
            // return doCompare(comparator,what0,what1);
            return comparator.compare(what0, what1);
        }
    }

    @SuppressWarnings("rawtypes")
    public Comparator getComparator() {
        return comparator;
    }

    @SuppressWarnings("rawtypes")
    public void setComparator(final Comparator comparator) {
        this.comparator = comparator;
    }

    public StringComparator getStringComparator() {
        return stringComparator;
    }

    public void setStringComparator(final StringComparator stringComparator) {
        this.stringComparator = stringComparator;
    }

    public String getCmpWhat() {
        return cmpWhat;
    }

    public boolean isAsc() {
        return asc;
    }

    public boolean isNullFirst() {
        return nullFirst;
    }

    public void setNullFirst(boolean nullFirst) {
        this.nullFirst = nullFirst;
    }

}