com.draagon.meta.manager.ObjectComparator.java Source code

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Here is the source code for com.draagon.meta.manager.ObjectComparator.java

Source

/*
 * Copyright 2003 Draagon Software LLC. All Rights Reserved.
 *
 * This software is the proprietary information of Draagon Software LLC.
 * Use is subject to license terms.
 */

package com.draagon.meta.manager;

import com.draagon.meta.field.MetaField;
import com.draagon.meta.loader.MetaDataLoader;
import com.draagon.meta.object.MetaObject;
import com.draagon.meta.*;
import com.draagon.meta.manager.exp.SortOrder;

import java.util.*;

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

public class ObjectComparator implements Comparator<Object> {
    private static Log log = LogFactory.getLog(ObjectComparator.class);

    private SortOrder mSort = null;

    public ObjectComparator(SortOrder sort) {
        mSort = sort;
    }

    public int compare(Object a, Object b) {
        try {
            return performCompare(a, b, mSort);
        } catch (MetaException e) {
            log.error(e.getMessage(), e);
            return 0;
        }
    }

    private int performCompare(Object a, Object b, SortOrder sort) throws MetaException {
        int rc = 0;

        if (sort == null)
            return 0;

        MetaObject ma = MetaDataLoader.findMetaObject(a);
        MetaObject mb = MetaDataLoader.findMetaObject(b);

        if (!ma.equals(mb))
            throw new MetaException("Objects are not of the same MetaClass: [" + ma + "] != [" + mb + "]");

        MetaField mf = ma.getMetaField(sort.getField());

        //try
        //{
        Object aVal = mf.getObject(a);
        Object bVal = mf.getObject(b);

        if (aVal == null && bVal == null)
            rc = 0;
        else if (aVal == null && bVal != null)
            rc = -1;
        else if (aVal != null && bVal == null)
            rc = 1;
        else {
            if (!aVal.getClass().equals(bVal.getClass()))
                throw new MetaException("Object data values are not of the same type");

            switch (mf.getType()) {
            case MetaField.BOOLEAN: {
                if (!((Boolean) aVal).booleanValue() && ((Boolean) bVal).booleanValue())
                    rc = -1;
                else if (((Boolean) aVal).booleanValue() == ((Boolean) bVal).booleanValue())
                    rc = 0;
                else if (((Boolean) aVal).booleanValue() && !((Boolean) bVal).booleanValue())
                    rc = 1;
                break;
            }
            case MetaField.BYTE:
                rc = ((Byte) aVal).compareTo((Byte) bVal);
                break;
            case MetaField.SHORT:
                rc = ((Short) aVal).compareTo((Short) bVal);
                break;
            case MetaField.INT:
                rc = ((Integer) aVal).compareTo((Integer) bVal);
                break;
            case MetaField.LONG:
                rc = ((Long) aVal).compareTo((Long) bVal);
                break;
            case MetaField.FLOAT:
                rc = ((Float) aVal).compareTo((Float) bVal);
                break;
            case MetaField.DOUBLE:
                rc = ((Double) aVal).compareTo((Double) bVal);
                break;
            case MetaField.STRING:
                rc = ((String) aVal).compareToIgnoreCase((String) bVal);
                break;
            case MetaField.DATE:
                rc = ((Date) aVal).compareTo((Date) bVal);
                break;

            // WARN:  Maybe try some reflection here or something for a compareTo operator
            case MetaField.OBJECT:
                rc = aVal.toString().compareTo(bVal.toString());
                break;
            }
        }
        //}
        //catch( Exception e ) {
        //  log.warn( "Error comparing field [" + a + "] with [" + b + "] for sort [" + sort + "]: " + e.getMessage(), e );
        //}

        if (rc == 0) {
            if (sort.hasNext())
                rc = performCompare(a, b, sort.getNext());
        } else {
            // If descending, then reverse the order
            if (sort.getOrder() == SortOrder.DESC)
                rc = -rc;
        }

        return rc;
    }
}