daterangepredicate.java

一个很好的开源项目管理系统源代码

package net.java.workeffort.infrastructure.utils;

import java.util.List;

import net.java.workeffort.infrastructure.Constants;

import org.apache.commons.beanutils.PropertyUtils;
import org.apache.commons.collections.Predicate;

/**
 * A predicate which returns rows which meet the filter criteria.
 * <p>
 * Used in date range validation of multiple rows
 * @author Antony Joseph
 */
public class DateRangePredicate implements Predicate {
    private Object bean;
    private List filterKeys;

    public DateRangePredicate(Object bean, List filterKeys) {
        if (filterKeys == null)
            throw new IllegalArgumentException("filterKeys cannot be null");
        if (bean == null)
            throw new IllegalArgumentException("bean cannot be null");
        this.bean = bean;
        this.filterKeys = filterKeys;
    }

    public boolean evaluate(Object row) {
        // if bean is a deleted row just return false;
        if (getSimpleProperty(bean, Constants.PROCESS_TYPE) != null
                && ((String) getSimpleProperty(bean, Constants.PROCESS_TYPE))
                        .equals(Constants.PROCESS_TYPE_DELETE)) {
            return false;
        }

        //Skip the same row.
        if (row == bean)
            return false;

        // no need to validate range against a row being deleted.
        if (getSimpleProperty(row, Constants.PROCESS_TYPE) != null
                && ((String) getSimpleProperty(row, Constants.PROCESS_TYPE))
                        .equals(Constants.PROCESS_TYPE_DELETE)) {
            return false;
        }

        for (int i = 0; i < filterKeys.size(); i++) {
            if (!getSimpleProperty(row, (String) filterKeys.get(i)).equals(
                    getSimpleProperty(bean, (String) filterKeys.get(i)))) {
                return false;
            }
        }

        return true;
    }

    private Object getSimpleProperty(Object obj, String propertyName) {
        try {
            return PropertyUtils.getSimpleProperty(obj, propertyName);
        }
        catch (Exception e) {
            throw new RuntimeException("Error while getting property:"
                    + propertyName + " from object:" + obj, e);
        }
    }

}