com.itextpdf.text.pdf.RandomAccessFileOrArray Maven / Gradle / Ivy
/*
*
* This file is part of the iText (R) project.
* Copyright (c) 1998-2016 iText Group NV
* Authors: Bruno Lowagie, Paulo Soares, et al.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License version 3
* as published by the Free Software Foundation with the addition of the
* following permission added to Section 15 as permitted in Section 7(a):
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* or FITNESS FOR A PARTICULAR PURPOSE.
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* Boston, MA, 02110-1301 USA, or download the license from the following URL:
* http://itextpdf.com/terms-of-use/
*
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* Section 5 of the GNU Affero General Public License.
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*
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package com.itextpdf.text.pdf;
import com.itextpdf.text.Document;
import com.itextpdf.text.ExceptionConverter;
import com.itextpdf.text.io.IndependentRandomAccessSource;
import com.itextpdf.text.io.RandomAccessSource;
import com.itextpdf.text.io.RandomAccessSourceFactory;
import java.io.DataInput;
import java.io.DataInputStream;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
/** Intended to be layered on top of a low level RandomAccessSource object. Provides
* functionality useful during parsing:
*
* - tracks current position in the file
* - allows single byte pushback
* - allows reading of multi-byte data structures (int, long, String) for both Big and Little Endian representations
* - allows creation of independent 'views' of the underlying data source
*
*
* @author Paulo Soares, Kevin Day
*/
public class RandomAccessFileOrArray implements DataInput {
/**
* The source that backs this object
*/
private final RandomAccessSource byteSource;
/**
* The physical location in the underlying byte source.
*/
private long byteSourcePosition;
/**
* the pushed back byte, if any
*/
private byte back;
/**
* Whether there is a pushed back byte
*/
private boolean isBack = false;
/**
* @deprecated use {@link RandomAccessFileOrArray#RandomAccessFileOrArray(RandomAccessSource)} instead
* @param filename
* @throws IOException
*/
@Deprecated
public RandomAccessFileOrArray(String filename) throws IOException {
this(new RandomAccessSourceFactory()
.setForceRead(false)
.setUsePlainRandomAccess(Document.plainRandomAccess)
.createBestSource(filename));
}
/**
* Creates an independent view of the specified source. Closing the new object will not close the source.
* Closing the source will have adverse effect on the behavior of the new view.
* @deprecated use {@link RandomAccessFileOrArray#createView()} instead
* @param source the source for the new independent view
*/
@Deprecated
public RandomAccessFileOrArray(RandomAccessFileOrArray source) {
this(new IndependentRandomAccessSource(source.byteSource));
}
/**
* Creates an independent view of this object (with it's own file pointer and pushback queue). Closing the new object will not close this object.
* Closing this object will have adverse effect on the view.
* @return the new view
*/
public RandomAccessFileOrArray createView(){
return new RandomAccessFileOrArray(new IndependentRandomAccessSource(byteSource));
}
public RandomAccessSource createSourceView() {
return new IndependentRandomAccessSource(byteSource);
}
/**
* Creates a RandomAccessFileOrArray that wraps the specified byte source. The byte source will be closed when
* this RandomAccessFileOrArray is closed.
* @param byteSource the byte source to wrap
*/
public RandomAccessFileOrArray(RandomAccessSource byteSource){
this.byteSource = byteSource;
}
/**
* Constructs a new RandomAccessFileOrArrayObject
* @param filename the file to open (can be a file system file or one of the following url strings: file://, http://, https://, jar:, wsjar:, vfszip:
* @param forceRead if true, the entire file will be read into memory
* @param plainRandomAccess if true, a regular RandomAccessFile is used to access the file contents. If false, a memory mapped file will be used, unless the file cannot be mapped into memory, in which case regular RandomAccessFile will be used
* @throws IOException if there is a failure opening or reading the file
* @deprecated use {@link RandomAccessSourceFactory#createBestSource(String)} and {@link RandomAccessFileOrArray#RandomAccessFileOrArray(RandomAccessSource)} instead
*/
@Deprecated
public RandomAccessFileOrArray(String filename, boolean forceRead, boolean plainRandomAccess) throws IOException {
this(new RandomAccessSourceFactory()
.setForceRead(forceRead)
.setUsePlainRandomAccess(plainRandomAccess)
.createBestSource(filename));
}
/**
* @param url
* @throws IOException
* @deprecated use {@link RandomAccessSourceFactory#createSource(URL)} and {@link RandomAccessFileOrArray#RandomAccessFileOrArray(RandomAccessSource)} instead
*/
@Deprecated
public RandomAccessFileOrArray(URL url) throws IOException {
this (new RandomAccessSourceFactory().createSource(url));
}
/**
* @param is
* @throws IOException
* @deprecated use {@link RandomAccessSourceFactory#createSource(InputStream)} and {@link RandomAccessFileOrArray#RandomAccessFileOrArray(RandomAccessSource)} instead
*/
@Deprecated
public RandomAccessFileOrArray(InputStream is) throws IOException {
this (new RandomAccessSourceFactory().createSource(is));
}
/**
* @param arrayIn byte[]
* @throws IOException
* @deprecated use {@link RandomAccessSourceFactory#createSource(byte[])} and {@link RandomAccessFileOrArray#RandomAccessFileOrArray(RandomAccessSource)} instead
*/
@Deprecated
public RandomAccessFileOrArray(byte arrayIn[]) {
this (new RandomAccessSourceFactory().createSource(arrayIn));
}
@Deprecated
//TODO: I'm only putting this in here for backwards compatability with PdfReader(RAFOA, byte[]). Once we get rid of the
//PdfReader constructor, we can get rid of this method as well
protected RandomAccessSource getByteSource(){
return byteSource;
}
/**
* Pushes a byte back. The next get() will return this byte instead of the value from the underlying data source
* @param b the byte to push
*/
public void pushBack(byte b) {
back = b;
isBack = true;
}
/**
* Reads a single byte
* @return the byte, or -1 if EOF is reached
* @throws IOException
*/
public int read() throws IOException {
if(isBack) {
isBack = false;
return back & 0xff;
}
return byteSource.get(byteSourcePosition++);
}
public int read(byte[] b, int off, int len) throws IOException {
if (len == 0)
return 0;
int count = 0;
if (isBack && len > 0) {
isBack = false;
b[off++] = back;
--len;
count++;
}
if (len > 0){
int byteSourceCount = byteSource.get(byteSourcePosition, b, off, len);
if (byteSourceCount > 0) {
count += byteSourceCount;
byteSourcePosition += byteSourceCount;
}
}
if (count == 0)
return -1;
return count;
}
public int read(byte b[]) throws IOException {
return read(b, 0, b.length);
}
public void readFully(byte b[]) throws IOException {
readFully(b, 0, b.length);
}
public void readFully(byte b[], int off, int len) throws IOException {
int n = 0;
do {
int count = read(b, off + n, len - n);
if (count < 0)
throw new EOFException();
n += count;
} while (n < len);
}
public long skip(long n) throws IOException {
if (n <= 0) {
return 0;
}
int adj = 0;
if (isBack) {
isBack = false;
if (n == 1) {
return 1;
}
else {
--n;
adj = 1;
}
}
long pos;
long len;
long newpos;
pos = getFilePointer();
len = length();
newpos = pos + n;
if (newpos > len) {
newpos = len;
}
seek(newpos);
/* return the actual number of bytes skipped */
return newpos - pos + adj;
}
public int skipBytes(int n) throws IOException {
return (int)skip(n);
}
@Deprecated
//TODO: remove all references to this call, then remove this method
public void reOpen() throws IOException {
seek(0);
}
public void close() throws IOException {
isBack = false;
byteSource.close();
}
public long length() throws IOException {
return byteSource.length();
}
public void seek(long pos) throws IOException {
byteSourcePosition = pos;
isBack = false;
}
//TODO: consider changing method name to getPosition or something like that - might not be worth making a breaking change, though
public long getFilePointer() throws IOException {
return byteSourcePosition - (isBack ? 1 : 0);
}
public boolean readBoolean() throws IOException {
int ch = this.read();
if (ch < 0)
throw new EOFException();
return (ch != 0);
}
public byte readByte() throws IOException {
int ch = this.read();
if (ch < 0)
throw new EOFException();
return (byte)(ch);
}
public int readUnsignedByte() throws IOException {
int ch = this.read();
if (ch < 0)
throw new EOFException();
return ch;
}
public short readShort() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
if ((ch1 | ch2) < 0)
throw new EOFException();
return (short)((ch1 << 8) + ch2);
}
/**
* Reads a signed 16-bit number from this stream in little-endian order.
* The method reads two
* bytes from this stream, starting at the current stream pointer.
* If the two bytes read, in order, are
* b1 and b2, where each of the two values is
* between 0 and 255, inclusive, then the
* result is equal to:
*
* (short)((b2 << 8) | b1)
*
*
* This method blocks until the two bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next two bytes of this stream, interpreted as a signed
* 16-bit number.
* @exception EOFException if this stream reaches the end before reading
* two bytes.
* @exception IOException if an I/O error occurs.
*/
public final short readShortLE() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
if ((ch1 | ch2) < 0)
throw new EOFException();
return (short)((ch2 << 8) + (ch1 << 0));
}
public int readUnsignedShort() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
if ((ch1 | ch2) < 0)
throw new EOFException();
return (ch1 << 8) + ch2;
}
/**
* Reads an unsigned 16-bit number from this stream in little-endian order.
* This method reads
* two bytes from the stream, starting at the current stream pointer.
* If the bytes read, in order, are
* b1 and b2, where
* 0 <= b1, b2 <= 255,
* then the result is equal to:
*
* (b2 << 8) | b1
*
*
* This method blocks until the two bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next two bytes of this stream, interpreted as an
* unsigned 16-bit integer.
* @exception EOFException if this stream reaches the end before reading
* two bytes.
* @exception IOException if an I/O error occurs.
*/
public final int readUnsignedShortLE() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
if ((ch1 | ch2) < 0)
throw new EOFException();
return (ch2 << 8) + (ch1 << 0);
}
public char readChar() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
if ((ch1 | ch2) < 0)
throw new EOFException();
return (char)((ch1 << 8) + ch2);
}
/**
* Reads a Unicode character from this stream in little-endian order.
* This method reads two
* bytes from the stream, starting at the current stream pointer.
* If the bytes read, in order, are
* b1 and b2, where
* 0 <= b1, b2 <= 255,
* then the result is equal to:
*
* (char)((b2 << 8) | b1)
*
*
* This method blocks until the two bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next two bytes of this stream as a Unicode character.
* @exception EOFException if this stream reaches the end before reading
* two bytes.
* @exception IOException if an I/O error occurs.
*/
public final char readCharLE() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
if ((ch1 | ch2) < 0)
throw new EOFException();
return (char)((ch2 << 8) + (ch1 << 0));
}
public int readInt() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
int ch3 = this.read();
int ch4 = this.read();
if ((ch1 | ch2 | ch3 | ch4) < 0)
throw new EOFException();
return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + ch4);
}
/**
* Reads a signed 32-bit integer from this stream in little-endian order.
* This method reads 4
* bytes from the stream, starting at the current stream pointer.
* If the bytes read, in order, are b1,
* b2, b3, and b4, where
* 0 <= b1, b2, b3, b4 <= 255,
* then the result is equal to:
*
* (b4 << 24) | (b3 << 16) + (b2 << 8) + b1
*
*
* This method blocks until the four bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next four bytes of this stream, interpreted as an
* int.
* @exception EOFException if this stream reaches the end before reading
* four bytes.
* @exception IOException if an I/O error occurs.
*/
public final int readIntLE() throws IOException {
int ch1 = this.read();
int ch2 = this.read();
int ch3 = this.read();
int ch4 = this.read();
if ((ch1 | ch2 | ch3 | ch4) < 0)
throw new EOFException();
return ((ch4 << 24) + (ch3 << 16) + (ch2 << 8) + (ch1 << 0));
}
/**
* Reads an unsigned 32-bit integer from this stream. This method reads 4
* bytes from the stream, starting at the current stream pointer.
* If the bytes read, in order, are b1,
* b2, b3, and b4, where
* 0 <= b1, b2, b3, b4 <= 255,
* then the result is equal to:
*
* (b1 << 24) | (b2 << 16) + (b3 << 8) + b4
*
*
* This method blocks until the four bytes are read, the end of the
* stream is detected, or an exception is thrown.
*
* @return the next four bytes of this stream, interpreted as a
* long.
* @exception EOFException if this stream reaches the end before reading
* four bytes.
* @exception IOException if an I/O error occurs.
*/
public final long readUnsignedInt() throws IOException {
long ch1 = this.read();
long ch2 = this.read();
long ch3 = this.read();
long ch4 = this.read();
if ((ch1 | ch2 | ch3 | ch4) < 0)
throw new EOFException();
return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0));
}
public final long readUnsignedIntLE() throws IOException {
long ch1 = this.read();
long ch2 = this.read();
long ch3 = this.read();
long ch4 = this.read();
if ((ch1 | ch2 | ch3 | ch4) < 0)
throw new EOFException();
return ((ch4 << 24) + (ch3 << 16) + (ch2 << 8) + (ch1 << 0));
}
public long readLong() throws IOException {
return ((long)(readInt()) << 32) + (readInt() & 0xFFFFFFFFL);
}
public final long readLongLE() throws IOException {
int i1 = readIntLE();
int i2 = readIntLE();
return ((long)i2 << 32) + (i1 & 0xFFFFFFFFL);
}
public float readFloat() throws IOException {
return Float.intBitsToFloat(readInt());
}
public final float readFloatLE() throws IOException {
return Float.intBitsToFloat(readIntLE());
}
public double readDouble() throws IOException {
return Double.longBitsToDouble(readLong());
}
public final double readDoubleLE() throws IOException {
return Double.longBitsToDouble(readLongLE());
}
public String readLine() throws IOException {
StringBuilder input = new StringBuilder();
int c = -1;
boolean eol = false;
while (!eol) {
switch (c = read()) {
case -1:
case '\n':
eol = true;
break;
case '\r':
eol = true;
long cur = getFilePointer();
if ((read()) != '\n') {
seek(cur);
}
break;
default:
input.append((char)c);
break;
}
}
if ((c == -1) && (input.length() == 0)) {
return null;
}
return input.toString();
}
public String readUTF() throws IOException {
return DataInputStream.readUTF(this);
}
/** Reads a String from the font file as bytes using the given
* encoding.
* @param length the length of bytes to read
* @param encoding the given encoding
* @return the String read
* @throws IOException the font file could not be read
*/
public String readString(int length, String encoding) throws IOException {
byte buf[] = new byte[length];
readFully(buf);
try {
return new String(buf, encoding);
}
catch (Exception e) {
throw new ExceptionConverter(e);
}
}
}