totalhandler.java

exTreme taglib的使用

/*
 * Copyright 2004 original author or authors.
 *
 * Licensed under the Apache 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.apache.org/licenses/LICENSE-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.extremecomponents.table.handler;

import java.math.BigDecimal;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.apache.commons.beanutils.PropertyUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.extremecomponents.table.bean.Column;
import org.extremecomponents.table.core.BaseModel;
import org.extremecomponents.util.ExtremeUtils;

/**
 * @author phorn
 */
public class TotalHandler {
    private static Log logger = LogFactory.getLog(TotalHandler.class);
    private static final BigDecimal ZERO = new BigDecimal("0");

    private BaseModel model;
    private Map totals;

    public TotalHandler(BaseModel model) {
        this.model = model;
    }

    public Map getTotals() {
        return this.totals;
    }

    public void setTotals(Map totals) {
        this.totals = totals;
    }

    public void buildTotals(Collection rows)
            throws Exception {
        Map result = initializeTotalsMap(model.getColumnHandler());

        if (result == null) {
            return;
        }

        if (logger.isDebugEnabled()) {
            logger.debug("TotalHandler.buildTotals() - iterating keys for " + result);
        }

        iterateColumns(result, rows);

        if (logger.isDebugEnabled()) {
            logger.debug("TotalHandler.buildTotals() - totals = " + result);
        }

        this.totals = result;
    }

    private Map initializeTotalsMap(ColumnHandler columnHandler)
            throws Exception {
        Map result = null;

        if (columnHandler == null) {
            return result;
        }

        for (Iterator iter = columnHandler.getColumns().iterator(); iter.hasNext();) {
            Column column = (Column) iter.next();

            if (column.showTotal()) {
                if (result == null) {
                    result = new HashMap();
                }

                result.put(column.getProperty(), ZERO);
            }
        }

        return result;
    }

    private void iterateColumns(Map totals, Collection rows)
            throws Exception {
        for (Iterator iter = totals.keySet().iterator(); iter.hasNext();) {
            String property = (String) iter.next();
            iterateRows(totals, rows, property);
        }
    }

    private void iterateRows(Map totals, Collection rows, String property)
            throws Exception {
        for (Iterator listIter = rows.iterator(); listIter.hasNext();) {
            Object row = listIter.next();
            Object colVal = null;

            if (ExtremeUtils.isBeanPropertyReadable(row, property)) {
                colVal = PropertyUtils.getProperty(row, property);
            }

            if (colVal == null) {
                continue;
            }

            double totalVal = ((BigDecimal) totals.get(property)).doubleValue();

            if (colVal instanceof Number) {
                double sum = ((Number) colVal).doubleValue() + totalVal;
                totals.put(property, new BigDecimal(sum));
            } else {
                String colValStr = "" + colVal;
                if (StringUtils.isNotBlank(colValStr)) {
                    double colNumVal = 0.00;
                    try {
                        colNumVal = new BigDecimal(colValStr).doubleValue();
                    } catch (NumberFormatException e) {
                        String errorMessage = "Problem parsing numeric value for property [" + property
                                + "] with value [" + colValStr + "] to create a total!";
                        logger.error("TotalHandler.iterateRows() - " + errorMessage);
                    }
                    double sum = colNumVal + totalVal;
                    totals.put(property, new BigDecimal(sum));
                }
            }
        }
    }
}