de.intarsys.tools.file.MagicFileNumberTest Maven / Gradle / Ivy
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The basic runtime tools and interfaces for intarsys components.
/*
* Copyright (c) 2007, intarsys consulting GmbH
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* - Neither the name of intarsys nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package de.intarsys.tools.file;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import de.intarsys.tools.hex.HexTools;
import de.intarsys.tools.randomaccess.IRandomAccess;
import de.intarsys.tools.randomaccess.RandomAccessByteArray;
import de.intarsys.tools.stream.StreamTools;
public class MagicFileNumberTest {
public static class Type {
private String suffix;
private byte[] magicBytes;
public Type(String suffix, byte[] magic) {
this.suffix = suffix;
this.magicBytes = magic;
}
public String getKey() {
return HexTools.bytesToHexString(magicBytes);
}
public byte[] getMagicBytes() {
return magicBytes;
}
public String getSuffix() {
return suffix;
}
public boolean matches(IRandomAccess data) throws IOException {
data.reset();
for (int i = 0; i < magicBytes.length; i++) {
if (magicBytes[i] != data.read()) {
return false;
}
}
return true;
}
@Override
public String toString() {
return suffix;
}
}
static private Map types;
static {
types = new HashMap();
addTypes();
}
/**
* @param fileSuffix
* just the suffix without any starting suffix delimiters (e.g.:
* 'pdf')
* @param magicBytes
* any bytes, not null or zero size
*/
static public void addType(String fileSuffix, byte[] magicBytes) {
if ((fileSuffix == null) || (magicBytes == null)
|| (magicBytes.length == 0)) {
return;
}
Type type = new Type(fileSuffix, magicBytes);
if (!types.containsKey(type.getKey())) {
types.put(type.getKey(), type);
}
}
static protected void addTypes() {
/*
* known types, found on
* http://www.astro.keele.ac.uk/oldusers/rno/Computing/File_magic.html
*/
/* image files */
/* Bitmap format */
addType("bmp", new byte[] { 0x42, 0x4d }); //$NON-NLS-1$
/* FITS format */
addType("fits", new byte[] { 0x53, 0x49, 0x4d, 0x50, 0x4c, 0x45 }); //$NON-NLS-1$
/* GIF format */
addType("gif", new byte[] { 0x47, 0x49, 0x46, 0x38 }); //$NON-NLS-1$
/* Graphics Kernel System */
addType("gks", new byte[] { 0x47, 0x4b, 0x53, 0x4d }); //$NON-NLS-1$
/* IRIS rgb format */
addType("rgb", new byte[] { 0x01, (byte) 0xda }); //$NON-NLS-1$
/* ITC (CMU WM) format */
addType("itc", new byte[] { (byte) 0xf1, 0x00, 0x40, (byte) 0xbb }); //$NON-NLS-1$
/* JPEG File Interchange Format */
addType("jpg", new byte[] { (byte) 0xff, (byte) 0xD8, (byte) 0xff }); //$NON-NLS-1$
/* NIFF (Navy TIFF) */
addType("nif", new byte[] { 0x49, 0x49, 0x4e, 0x31 }); //$NON-NLS-1$
/* PM format */
addType("pm", new byte[] { 0x56, 0x49, 0x45, 0x57 }); //$NON-NLS-1$
/* PNG format */
addType("png", new byte[] { (byte) 0x89, 0x50, 0x4e, 0x47 }); //$NON-NLS-1$
/* Postscript format */
addType("ps", new byte[] { 0x25, 0x21 }); //$NON-NLS-1$
/* Sun Rasterfile */
addType("ras", new byte[] { 0x59, (byte) 0xa6, 0x6a, (byte) 0x95 }); //$NON-NLS-1$
/* TIFF format (Motorola - big endian) */
addType("tif", new byte[] { 0x4d, 0x4d, 0x00, 0x2a }); //$NON-NLS-1$
/* TIFF format (Intel - little endian) */
addType("tif", new byte[] { 0x49, 0x49, 0x2a, 0x00 }); //$NON-NLS-1$
/* XCF Gimp file structure */
addType("xcf", new byte[] { 0x67, 0x69, 0x6d, 0x70, 0x20, 0x78, 0x63, //$NON-NLS-1$
0x66, 0x20, 0x76 });
/* Xfig format */
addType("fig", new byte[] { 0x23, 0x46, 0x49, 0x47 }); //$NON-NLS-1$
/* XPM format */
addType("xpm", new byte[] { 0x2f, 0x2a, 0x20, 0x58, 0x50, 0x4d, 0x20, //$NON-NLS-1$
0x2a, 0x2f });
/* compressed files */
/* Bzip */
addType("bz", new byte[] { 0x42, 0x5a }); //$NON-NLS-1$
/* Compress */
addType("Z", new byte[] { 0x1f, (byte) 0x9d }); //$NON-NLS-1$
/* gzip format */
addType("gz", new byte[] { 0x1f, (byte) 0x8b }); //$NON-NLS-1$
/* pkzip format */
addType("zip", new byte[] { 0x50, 0x4b, 0x03, 0x04 }); //$NON-NLS-1$
/* archive files */
/* TAR */
addType("tar", new byte[] { 0x75, 0x73, 0x74, 0x61, 0x72 }); //$NON-NLS-1$
/* excecutable files */
/* MS-DOS, OS/2 or MS Windows */
addType("exe", new byte[] { 0x4d, 0x5a }); //$NON-NLS-1$
/* Unix elf */
addType("unix elf", new byte[] { 0x7f, 0x45, 0x4c, 0x46 }); //$NON-NLS-1$
/* pgp */
/* pgp public ring */
addType("pgp public ring", new byte[] { (byte) 0x99, 0x00 }); //$NON-NLS-1$
/* pgp security ring */
addType("pgp security ring", new byte[] { (byte) 0x95, 0x01 }); //$NON-NLS-1$
/* pgp security ring */
addType("pgp security ring", new byte[] { (byte) 0x95, 0x00 }); //$NON-NLS-1$
/* pgp encrypted data */
addType("pgp encrypted data", new byte[] { (byte) 0xA6, 0x00 }); //$NON-NLS-1$
/* other */
try {
addType("pdf", "%PDF".getBytes("ASCII")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
} catch (UnsupportedEncodingException e) {
// will not happen
}
}
/**
* @param data
* any not null or zero size data
* @return a file suffix without a delimiter (e.g.: 'pdf') or
* null
*/
static public String guessFileSuffix(byte[] data) {
if (data == null) {
return null;
}
IRandomAccess ra = null;
try {
ra = new RandomAccessByteArray(data);
return guessFileSuffix(ra);
} catch (IOException e) {
// should not occur
throw new RuntimeException(e);
} finally {
StreamTools.close(ra);
}
}
/**
* @param data
* any not null or zero size data
* @return a file suffix without a delimiter (e.g.: 'pdf') or
* null
*/
static public String guessFileSuffix(IRandomAccess data) throws IOException {
for (Iterator i = types.entrySet().iterator(); i.hasNext();) {
Type type = (Type) ((Map.Entry) i.next()).getValue();
if (type.matches(data)) {
return type.getSuffix();
}
}
return null;
}
/**
* does the data contain only ISO-8819-x printable characters ?
*/
static public boolean isText(byte[] data) {
IRandomAccess ra = null;
try {
ra = new RandomAccessByteArray(data);
return isText(ra);
} catch (IOException e) {
// should not occur
throw new RuntimeException(e);
} finally {
StreamTools.close(ra);
}
}
/**
* does the data contain only ISO-8819-x printable characters ?
*/
static public boolean isText(IRandomAccess data) throws IOException {
if (data == null) {
return false;
}
data.reset();
for (int i = 0, c = data.read(); c != -1 && i < 1024; c = data.read(), i++) {
c = c & 0xFF;
if (c >= 0x20 && c <= 0x7E) {
// ASCII printable
continue;
}
if (c >= 0xA0) {
// ISO 8819 extension
continue;
}
switch (c) {
case 0x09: // HORIZONTAL TABULATION
case 0x0A: // LINE FEED
case 0x0B: // VERTICAL TABULATION
case 0x0C: // FORM FEED
case 0x0D: // CARRIAGE RETURN
continue;
default:
}
return false;
}
return true;
}
private MagicFileNumberTest() {
}
}
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