foreachtag.java

一个java生成自动生成Excel

package net.sf.jxls.tag;

import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;

import net.sf.jxls.exception.ParsePropertyException;
import net.sf.jxls.parser.Expression;
import net.sf.jxls.transformation.ResultTransformation;
import net.sf.jxls.transformer.Configuration;
import net.sf.jxls.transformer.SheetTransformer;
import net.sf.jxls.util.GroupData;
import net.sf.jxls.util.ReportUtil;
import net.sf.jxls.util.Util;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.poi.hssf.usermodel.HSSFRow;

/**
 * jx:forEach tag implementation
 *
 * @author Leonid Vysochyn
 */
public class ForEachTag extends BaseTag {
    protected final Log log = LogFactory.getLog(getClass());

    public static final String TAG_NAME = "forEach";
    Configuration configuration = new Configuration();
    static final String GROUP_DATA_KEY = "group";

    private String select;

    public ForEachTag() {
        name = TAG_NAME;
    }

    private String items;
    private String var;
    private String varStatus;

    private String itemsKey;
    private String collectionPropertyName;
    private String groupBy;

    private String groupOrder;

    private Collection itemsCollection;


    public String getSelect() {
        return select;
    }

    public void setSelect(String select) {
        this.select = select;
    }

    public String getGroupOrder() {
        return groupOrder;
    }

    public void setGroupOrder(String groupOrder) {
        this.groupOrder = groupOrder;
    }

    public String getItems() {
        return items;
    }

    public void setItems(String items) {
        this.items = items;
    }

    public String getVar() {
        return var;
    }

    public void setVar(String var) {
        this.var = var;
    }

    public String getGroupBy() {
        return groupBy;
    }

    public void setGroupBy(String groupBy) {
        this.groupBy = groupBy;
    }

    public String getVarStatus() {
        return varStatus;
    }

    public void setVarStatus(String varStatus) {
        this.varStatus = varStatus;
    }

    public void init(TagContext tagContext) {
        super.init(tagContext);
        configuration = tagContext.getSheet().getConfiguration();
        parseItemsProperty();
        parseSelectProperty();
        if (tagContext.getBeans().containsKey(itemsKey)) {
            Object itemsObject = tagContext.getBeans().get(itemsKey);
            if (collectionPropertyName != null) {
                itemsCollection = (Collection) Util.getProperty(itemsObject, collectionPropertyName);
            } else {
                itemsCollection = (Collection) itemsObject;
            }
        }
    }

    private void parseSelectProperty() {
        if (select != null) {
            if (select.startsWith(configuration.getStartExpressionToken()) && select.endsWith(configuration.getEndExpressionToken())) {
                select = select.substring(2, select.length() - 1);
            } else {
                log.error("select attribute should start with " + configuration.getStartExpressionToken() + " and end with " +
                        configuration.getEndExpressionToken());
            }
        }
    }


    private void parseItemsProperty() {
        if (items != null) {
            if (items.startsWith(configuration.getStartExpressionToken()) && items.endsWith(configuration.getEndExpressionToken())) {
                items = items.substring(2, items.length() - 1);

                try {
                    Expression expr = new Expression(items, tagContext.getBeans(), configuration);
                    Object obj = expr.evaluate();
                    if (obj instanceof Collection) {
                        itemsCollection = (Collection) obj;
                    } else {
                        throw new RuntimeException("items property in forEach tag must be a collection. " + items + " is not ");
                    }
                } catch (Exception e) {
                    throw new RuntimeException("Can't parse an expression " + items, e);
                }
            } else {
                log.error("items attribute should start from " + configuration.getStartExpressionToken() + " and end " +
                        "with " + configuration.getEndExpressionToken());
            }
        } else {
            log.error("Collection key is null");
        }
    }


    public ResultTransformation process(SheetTransformer sheetTransformer) {
        if (log.isDebugEnabled()) {
            log.debug("forEach tag processing. Attributes: var = " + var + ", items=" + items);
            log.debug("Current tagContext: " + tagContext);
            log.debug("Items Collection: " + itemsCollection);
        }
        Block body = tagContext.getTagBody();
        if (body.getNumberOfRows() == 1) {
            return processOneRowTag(sheetTransformer);
        }
        int shiftNumber = 0;
        if (itemsCollection != null && !itemsCollection.isEmpty()) {
            tagContext.getSheetTransformationController().removeBorders(body);
            shiftNumber += -2; // due to the borders
            ResultTransformation shift = new ResultTransformation(0);
            Map beans = tagContext.getBeans();

            if (groupBy == null || groupBy.length() == 0) {
                Collection collectionToProcess = selectCollectionDataToProcess(beans);
                shiftNumber += tagContext.getSheetTransformationController().duplicateDown(body, collectionToProcess.size() - 1);
                shift = processCollectionItems(collectionToProcess, beans, body, sheetTransformer);
            } else {
                try {
                    Collection groupedData = ReportUtil.groupCollectionData(itemsCollection, groupBy, groupOrder, select, configuration);
                    shiftNumber += tagContext.getSheetTransformationController().duplicateDown(body, groupedData.size() - 1);
                    Object savedGroupData = null;
                    if (beans.containsKey(GROUP_DATA_KEY)) {
                        savedGroupData = beans.get(GROUP_DATA_KEY);
                    }