org.jpedal.io.RandomAccessDataBuffer 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/java-pdf-library-support/
*
* (C) Copyright 1997-2013, IDRsolutions and Contributors.
*
* This file is part of JPedal
*
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* ---------------
* RandomAccessDataBuffer.java
* ---------------
*/
package org.jpedal.io;
import java.io.IOException;
public class RandomAccessDataBuffer implements RandomAccessBuffer {
private byte[] data;
private long pointer;
public RandomAccessDataBuffer(byte[] data) {
this.data = data;
this.pointer = -1;
}
@Override
public long getFilePointer() throws IOException {
return this.pointer;
}
@Override
public void seek(long pos) throws IOException {
if (checkPos(pos)) {
this.pointer = pos;
}
else {
throw new IOException("Position out of bounds");
}
}
@Override
public void close() throws IOException {
this.data = null;
this.pointer = -1;
}
@Override
public long length() throws IOException {
if (this.data != null) {
return this.data.length;
}
else {
throw new IOException("Data buffer not initialized.");
}
}
@Override
public int read() throws IOException {
if (checkPos(this.pointer)) {
return b2i(this.data[(int) this.pointer++]);
}
else {
return -1;
}
}
private int peek() throws IOException {
if (checkPos(this.pointer)) {
return b2i(this.data[(int) this.pointer]);
}
else {
return -1;
}
}
/**
* return next line (returns null if no line)
*/
@Override
public String readLine() throws IOException {
if (this.pointer >= this.data.length - 1) {
return null;
}
else {
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(byte[] b) throws IOException {
if (this.data == null) throw new IOException("Data buffer not initialized.");
if (this.pointer < 0 || this.pointer >= this.data.length) return -1;
final int length = Math.min(b.length, this.data.length - (int) this.pointer);
for (int i = 0; i < length; i++) {
b[i] = this.data[(int) this.pointer++];
}
return length;
}
private static int b2i(byte b) {
if (b >= 0) return b;
return 256 + b;
}
private boolean checkPos(long pos) throws IOException {
return ((pos >= 0) && (pos < length()));
}
/* returns the byte data */
@Override
public byte[] getPdfBuffer() {
return this.data;
}
}