complexfeaturejoinrowmaker.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

// **********************************************************************
// <copyright>
//  BBN Technologies
//  10 Moulton Street
//  Cambridge, MA 02138
//  [phone]
// 
//  Copyright (C) BBNT Solutions LLC. All rights reserved.
// </copyright>
// **********************************************************************
// $Source: /cvs/distapps/openmap/src/vpfservlet/WEB-INF/src/com/bbn/openmap/vpfservlet/ComplexFeatureJoinRowMaker.java,v $
// $Revision: 1.2.2.2 $ $Date: 2005/08/11 21:03:07 $ $Author: dietrick $
// **********************************************************************
package com.bbn.openmap.vpfservlet;

import java.io.File;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import com.bbn.openmap.io.FormatException;
import com.bbn.openmap.layer.util.html.TableDataElement;
import com.bbn.openmap.layer.util.html.TableRowElement;
import com.bbn.openmap.layer.vpf.DcwRecordFile;
import com.bbn.openmap.layer.vpf.VPFUtil;

/**
 * A RowMaker that performs the join in a feature index table.
 */
public class ComplexFeatureJoinRowMaker extends PlainRowMaker {
    /** a list reused to load primitive rows */
    final List primRow = new ArrayList();
    /** a list reused to load feature rows */
    final List featureRow = new ArrayList();

    /** the array of feature tables, each index is lazy-initialized */
    final DcwRecordFile[] featureTables;

    /**
     * Construct a rowmaker for a complex feature join.
     * @param drf the table
     * @throws FormatException some error was encountered
     */
    public ComplexFeatureJoinRowMaker(DcwRecordFile drf) throws FormatException {
        featureTables = getTables(drf);
    }

    public void addToRow(TableRowElement row, List l) {
        try {
            boolean color1 = false;
            int i = 0;
            for (Iterator li = l.iterator(); li.hasNext(); ) {
                Object o = li.next();
                DcwRecordFile featureTable = featureTables[i++];
                if ((featureTable != null) &&
                    featureTable.getRow(featureRow, VPFUtil.objectToInt(o))) {
                    color1 = !color1;
                    for (Iterator fi = featureRow.iterator(); fi.hasNext(); ) {
                        row.addElement(new TableDataElement(color1 ? "CLASS=JoinColumn" : "CLASS=Join2Column",
                                                            fi.next().toString()));
                    }
                } else {
                    row.addElement(o.toString());
                }
            }
        } catch (FormatException fe) {
            row.addElement(fe.toString());
        }
    }

    public DcwRecordFile[] getTables(DcwRecordFile drf) throws FormatException {
        DcwRecordFile[] retval = new DcwRecordFile[drf.getColumnCount()];
        File dirPath = new File(drf.getTableFile()).getParentFile();
        File fcsfile = new File(dirPath, "fcs");
        if (!fcsfile.canRead()) {
            fcsfile = new File(dirPath, "fcs.");
        }
        DcwRecordFile fcs = new DcwRecordFile(fcsfile.toString());
        List l = new ArrayList(fcs.getColumnCount());
        String tableName = drf.getTableName();

        int table1Column = fcs.whatColumn("table1");
        int table1_keyColumn = fcs.whatColumn("table1_key");
        int table2Column = fcs.whatColumn("table2");
        int table2_keyColumn = fcs.whatColumn("table2_key");

        while (fcs.parseRow(l)) {
            String table1 = (String)l.get(table1Column);
            String table1_key = (String)l.get(table1_keyColumn);
            String table2 = (String)l.get(table2Column);
            String table2_key = (String)l.get(table2_keyColumn);
            if (table1.equalsIgnoreCase(tableName) &&
                table2_key.equalsIgnoreCase("id")) {
                int indexCol = drf.whatColumn(table1_key);
                retval[indexCol] = new DcwRecordFile(dirPath + File.separator + table2);
            }
        }

        fcs.close();
        return retval;
    }

    public void close() {
        for (int i = 0; i < featureTables.length; i++) {
            DcwRecordFile drf = featureTables[i];
            if (drf != null) {
                drf.close();
            }
        }
    }
}