org.jpedal.io.RandomAccessFCTest Maven / Gradle / Ivy

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/*
 * ===========================================
 * Java Pdf Extraction Decoding Access Library
 * ===========================================
 *
 * Project Info:  http://www.idrsolutions.com
 * Help section for developers at http://www.idrsolutions.com/support/
 *
 * (C) Copyright 1997-2017 IDRsolutions and Contributors.
 *
 * This file is part of JPedal/JPDF2HTML5
 *
 @LICENSE@
 *
 * ---------------
 * RandomAccessFCTest.java
 * ---------------
 */

package org.jpedal.io;

import java.io.FileInputStream;
import java.io.IOException;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;

import org.jpedal.utils.LogWriter;


public class RandomAccessFCTest implements RandomAccessBuffer {

    //private byte[] data;
    private long pointer;

    private int length;

    private FileChannel fc;

    private MappedByteBuffer mb;

    public RandomAccessFCTest(final FileInputStream inFile) {

        try {

            length = inFile.available();
            fc = (inFile).getChannel();

            mb = fc.map(FileChannel.MapMode.READ_ONLY, 0L, fc.size());

        } catch (final Exception e) {
            LogWriter.writeLog("Exception: " + e.getMessage());
        }
    }

    @Override
    public long getFilePointer() throws IOException {
        return pointer;
    }

    @Override
    public void seek(final long pos) throws IOException {
        if (checkPos(pos)) {
            this.pointer = pos;
        } else {
            throw new IOException("Position out of bounds");
        }
    }

    @Override
    public void close() throws IOException {

        if (fc != null) {

            fc.close();
            fc = null;
        }

        if (mb != null) {

            mb = null;
        }

        this.pointer = -1;

    }

    /**/
    @Override
    protected void finalize() {

        try {
            super.finalize();
        } catch (final Throwable e) {
            LogWriter.writeLog("Exception: " + e.getMessage());
        }

        //ensure removal actual file
        try {
            close();
        } catch (final IOException e) {
            LogWriter.writeLog("Exception: " + e.getMessage());
        }
    }

    @Override
    public long length() throws IOException {

        if (mb != null) {
            return length;
        } else {
            throw new IOException("Data buffer not initialized.");
        }
    }

    @Override
    public int read() throws IOException {

        if (checkPos(this.pointer)) {

            mb.position((int) pointer);

            pointer++;

            return mb.get();
        } else {
            return -1;
        }
    }

    private int peek() throws IOException {

        if (checkPos(this.pointer)) {

            mb.position((int) pointer);

            return mb.get();
        } else {
            return -1;
        }
    }

    /**
     * return next line (returns null if no line)
     */
    @Override
    public String readLine() throws IOException {

        if (this.pointer >= this.length - 1) {
            return null;
        } else {

            final StringBuilder buf = new StringBuilder();
            int c;
            while ((c = read()) >= 0) {
                if ((c == 10) || (c == 13)) {
                    if (((peek() == 10) || (peek() == 13)) && (peek() != c)) {
                        read();
                    }
                    break;
                }
                buf.append((char) c);
            }
            return buf.toString();
        }
    }

    @Override
    public int read(final byte[] b) throws IOException {

        if (mb == null) {
            throw new IOException("Data buffer not initialized.");
        }

        if (pointer < 0 || pointer >= length) {
            return -1;
        }

        int length = this.length - (int) pointer;
        if (length > b.length) {
            length = b.length;
        }

        for (int i = 0; i < length; i++) {

            mb.position((int) pointer);

            pointer++;
            b[i] = mb.get();

        }

        return length;
    }

    private boolean checkPos(final long pos) throws IOException {
        return ((pos >= 0) && (pos < length()));
    }

    /* returns the byte data*/
    @Override
    public byte[] getPdfBuffer() {

        final byte[] bytes = new byte[length];

        mb.position(0);
        mb.get(bytes);

        return bytes;
    }
}