ddffielddefinition.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 (c) 1999, Frank Warmerdam
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ******************************************************************************/

package com.bbn.openmap.dataAccess.iso8211;

import com.bbn.openmap.layer.vpf.MutableInt;
import com.bbn.openmap.util.Debug;
import com.bbn.openmap.util.PropUtils;

import java.util.Iterator;
import java.util.Vector;

/**
 * Information from the DDR defining one field. Note that just because
 * a field is defined for a DDFModule doesn't mean that it actually
 * occurs on any records in the module. DDFFieldDefns are normally
 * just significant as containers of the DDFSubfieldDefinitions.
 */
public class DDFFieldDefinition implements DDFConstants {

    protected DDFModule poModule;
    protected String pszTag;

    protected String _fieldName;
    protected String _arrayDescr;
    protected String _formatControls;

    protected boolean bRepeatingSubfields;
    protected int nFixedWidth; // zero if variable.

    protected DataStructCode _data_struct_code;
    protected DataTypeCode _data_type_code;

    protected Vector paoSubfieldDefns;

    /**
     * Fetch a pointer to the field name (tag).
     * 
     * @return this is an internal copy and shouldn't be freed.
     */
    public String getName() {
        return pszTag;
    }

    /**
     * Fetch a longer descriptio of this field.
     * 
     * @return this is an internal copy and shouldn't be freed.
     */
    public String getDescription() {
        return _fieldName;
    }

    /**
     * Get the number of subfields.
     */
    public int getSubfieldCount() {
        if (paoSubfieldDefns != null) {
            return paoSubfieldDefns.size();
        }
        return 0;
    }

    /**
     * Get the width of this field. This function isn't normally used
     * by applications.
     * 
     * @return The width of the field in bytes, or zero if the field
     *         is not apparently of a fixed width.
     */
    public int getFixedWidth() {
        return nFixedWidth;
    }

    /**
     * Fetch repeating flag.
     * 
     * @return true if the field is marked as repeating.
     */
    public boolean isRepeating() {
        return bRepeatingSubfields;
    }

    /** this is just for an S-57 hack for swedish data */
    public void setRepeating(boolean val) {
        bRepeatingSubfields = val;
    }

    /** ********************************************************************* */
    /* DDFFieldDefn() */
    /** ********************************************************************* */

    public DDFFieldDefinition() {
        poModule = null;
        pszTag = null;
        _fieldName = null;
        _arrayDescr = null;
        _formatControls = null;
        paoSubfieldDefns = null;
        bRepeatingSubfields = false;
    }

    public DDFFieldDefinition(DDFModule poModuleIn, String pszTagIn,
            byte[] pachFieldArea) {

        initialize(poModuleIn, pszTagIn, pachFieldArea);
    }

    /**
     * Initialize the field definition from the information in the DDR
     * record. This is called by DDFModule.open().
     * 
     * @param poModuleIn DDFModule reprsenting file being read.
     * @param pszTagIn the name of this field.
     * @param pachFieldArea the data bytes in the file representing
     *        the field from the header.
     */
    public boolean initialize(DDFModule poModuleIn, String pszTagIn,
                              byte[] pachFieldArea) {

        /// pachFieldArea needs to be specified better. It's an
        /// offset into a character array, and we need to know what
        // it
        /// is to scope it better in Java.

        int iFDOffset = poModuleIn._fieldControlLength;

        poModule = poModuleIn;
        pszTag = pszTagIn;

        /* -------------------------------------------------------------------- */
        /* Set the data struct and type codes. */
        /* -------------------------------------------------------------------- */
        _data_struct_code = DataStructCode.get((char) pachFieldArea[0]);
        _data_type_code = DataTypeCode.get((char) pachFieldArea[1]);

        if (Debug.debugging("iso8211")) {
            Debug.output("DDFFieldDefinition.initialize(" + pszTagIn
                    + "):\n\t\t data_struct_code = " + _data_struct_code
                    + "\n\t\t data_type_code = " + _data_type_code
                    + "\n\t\t iFDOffset = " + iFDOffset);
        }

        /* -------------------------------------------------------------------- */
        /* Capture the field name, description (sub field names), and */
        /* format statements. */
        /* -------------------------------------------------------------------- */

        byte[] tempData = new byte[pachFieldArea.length - iFDOffset];
        System.arraycopy(pachFieldArea,
                iFDOffset,
                tempData,
                0,
                pachFieldArea.length - iFDOffset);

        MutableInt nCharsConsumed = new MutableInt();

        _fieldName = DDFUtils.fetchVariable(tempData,
                tempData.length,
                DDF_UNIT_TERMINATOR,
                DDF_FIELD_TERMINATOR,
                nCharsConsumed);
        if (Debug.debugging("iso8211")) {
            Debug.output("DDFFieldDefinition.initialize(" + pszTagIn
                    + "): created field name " + _fieldName);
        }

        iFDOffset += nCharsConsumed.value;

        tempData = new byte[pachFieldArea.length - iFDOffset];
        System.arraycopy(pachFieldArea,
                iFDOffset,
                tempData,
                0,
                pachFieldArea.length - iFDOffset);
        _arrayDescr = DDFUtils.fetchVariable(tempData,
                tempData.length,
                DDF_UNIT_TERMINATOR,
                DDF_FIELD_TERMINATOR,
                nCharsConsumed);
        iFDOffset += nCharsConsumed.value;

        tempData = new byte[pachFieldArea.length - iFDOffset];
        System.arraycopy(pachFieldArea,
                iFDOffset,
                tempData,
                0,
                pachFieldArea.length - iFDOffset);

        _formatControls = DDFUtils.fetchVariable(tempData,
                tempData.length,
                DDF_UNIT_TERMINATOR,
                DDF_FIELD_TERMINATOR,
                nCharsConsumed);

        /* -------------------------------------------------------------------- */
        /* Parse the subfield info. */
        /* -------------------------------------------------------------------- */
        if (_data_struct_code != DataStructCode.ELEMENTARY) {
            if (!buildSubfieldDefns(_arrayDescr)) {
                return false;
            }

            if (!applyFormats(_formatControls)) {
                return false;
            }
        }

        return true;
    }

    /**
     * Write out field definition info.
     * 
     * A variety of information about this field definition, and all
     * its subfields are written out too.
     */
    public String toString() {
        StringBuffer buf = new StringBuffer("  DDFFieldDefn:\n");
        buf.append("      Tag = " + pszTag + "\n");
        buf.append("      _fieldName = " + _fieldName + "\n");
        buf.append("      _arrayDescr = " + _arrayDescr + "\n");
        buf.append("      _formatControls = " + _formatControls + "\n");
        buf.append("      _data_struct_code = " + _data_struct_code + "\n");
        buf.append("      _data_type_code = " + _data_type_code + "\n");

        if (paoSubfieldDefns != null) {
            for (Iterator it = paoSubfieldDefns.iterator(); it.hasNext();) {
                buf.append((DDFSubfieldDefinition) it.next());
            }
        }

        return buf.toString();
    }

    /**
     * Based on the list contained in the string, build a set of
     * subfield definitions.
     */
    protected boolean buildSubfieldDefns(String pszSublist) {

        if (pszSublist.charAt(0) == '*') {
            bRepeatingSubfields = true;
            pszSublist = pszSublist.substring(1);
        }

        Vector papszSubfieldNames = PropUtils.parseMarkers(pszSublist, "!");

        paoSubfieldDefns = new Vector();

        for (Iterator it = papszSubfieldNames.iterator(); it.hasNext();) {
            DDFSubfieldDefinition ddfsd = new DDFSubfieldDefinition();
            ddfsd.setName((String) it.next());
            paoSubfieldDefns.add(ddfsd);
        }

        return true;
    }

    /**
     * Extract a substring terminated by a comma (or end of string).
     * Commas in brackets are ignored as terminated with bracket
     * nesting understood gracefully. If the returned string would
     * being and end with a bracket then strip off the brackets.
     * <P>
     * Given a string like "(A,3(B,C),D),X,Y)" return "A,3(B,C),D".
     * Give a string like "3A,2C" return "3A".
     */
    protected String extractSubstring(String pszSrc) {
        int nBracket = 0;
        int i;
        String pszReturn;

        for (i = 0; i < pszSrc.length()
                && (nBracket > 0 || pszSrc.charAt(i) != ','); i++) {
            if (pszSrc.charAt(i) == '(') {
                nBracket++;
            } else if (pszSrc.charAt(i) == ')') {
                nBracket--;
            }
        }

        if (pszSrc.charAt(0) == '(') {
            pszReturn = pszSrc.substring(1, i - 2);
        } else {
            pszReturn = pszSrc.substring(0, i);