core/src/main/java/org/datasyslab/geospark/formatMapper/shapefileParser/parseUtils/shp/ShpFileParser.java

/**
 * FILE: ShpFileParser.java
 * PATH: org.datasyslab.geospark.formatMapper.shapefileParser.parseUtils.shp.ShpFileParser.java
 * Copyright (c) 2015-2017 GeoSpark Development Team
 * All rights reserved.
 */
package org.datasyslab.geospark.formatMapper.shapefileParser.parseUtils.shp;

import org.apache.commons.io.EndianUtils;
import org.datasyslab.geospark.formatMapper.shapefileParser.shapes.ShpRecord;

import java.io.DataInputStream;
import java.io.IOException;
import java.io.Serializable;
import java.nio.ByteBuffer;

// TODO: Auto-generated Javadoc
/**
 * The Class ShpFileParser.
 */
public class ShpFileParser implements Serializable, ShapeFileConst{

    /** shape type of current .shp file */
    public int currentTokenType = 0;

    /**  lenth of file in bytes. */
    public long fileLength = 0;

    /**  remain length of bytes to parse. */
    public long remainLength = 0;

    /**  input reader. */
    ShapeReader reader = null;

    /**  current boundbox. */
    public static BoundBox boundBox = null;

    /**
     * create a new shape file parser with a input source that is instance of DataInputStream.
     *
     * @param inputStream the input stream
     */
    public ShpFileParser(DataInputStream inputStream) {
        reader = new DataInputStreamReader(inputStream);
    }

    /**
     * extract and validate information from .shp file header
     *
     * @throws IOException Signals that an I/O exception has occurred.
     */
    public void parseShapeFileHead()
            throws IOException
    {
        int fileCode = reader.readInt();
        reader.skip(HEAD_EMPTY_NUM * INT_LENGTH);
        fileLength = 16 * reader.readInt() - HEAD_FILE_LENGTH_16BIT * 16;
        remainLength = fileLength;
        int fileVersion = EndianUtils.swapInteger(reader.readInt());
        currentTokenType = EndianUtils.swapInteger(reader.readInt());
        // if bound box is not referenced, skip it
        if(boundBox == null) reader.skip(HEAD_BOX_NUM * DOUBLE_LENGTH);
        else{// else assign value
            for(int i = 0;i < HEAD_BOX_NUM; ++i){
                boundBox.set(i, EndianUtils.swapDouble(reader.readDouble()));
            }
        }
    }

    /**
     * abstract information from record header and then copy primitive bytes data of record to a primitive record.
     *
     * @return the shp record
     * @throws IOException Signals that an I/O exception has occurred.
     */
    public ShpRecord parseRecordPrimitiveContent() throws IOException{
        // get length of record content
        int contentLength = reader.readInt();
        long recordLength = 16 * (contentLength + 4);
        remainLength -= recordLength;
        int typeID = EndianUtils.swapInteger(reader.readInt());
        byte[] contentArray = new byte[contentLength * 2 - INT_LENGTH];// exclude the 4 bytes we read for shape type
        reader.read(contentArray,0,contentArray.length);
        return new ShpRecord(contentArray, typeID);
    }

    /**
     * abstract id number from record header.
     *
     * @return the int
     * @throws IOException Signals that an I/O exception has occurred.
     */
    public int parseRecordHeadID() throws IOException{
        int id = reader.readInt();
        return id;
    }

    /**
     * get current progress of parsing records.
     *
     * @return the progress
     */
    public float getProgress(){
        return 1 - (float)remainLength / (float) fileLength;
    }

}