org.jwat.common.EncodedWords Maven / Gradle / Ivy
/**
* Java Web Archive Toolkit - Software to read and validate ARC, WARC
* and GZip files. (http://jwat.org/)
* Copyright 2011-2012 Netarkivet.dk (http://netarkivet.dk/)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jwat.common;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CoderMalfunctionError;
import java.nio.charset.CoderResult;
import java.nio.charset.CodingErrorAction;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
/**
* Class used to decode and validate an Encoded-Word string as specified
* in RFC 2047.
*
* Examples:
* =?US-ASCII?Q?Keith_Moore?=
* =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?=
* =?ISO-8859-1?Q?Andr=E9?=
* =?ISO-8859-1?B?SWYgeW91IGNhbiByZWFkIHRoaXMgeW8=?=
* =?ISO-8859-2?B?dSB1bmRlcnN0YW5kIHRoZSBleGFtcGxlLg==?=
*
* @author nicl
*/
public class EncodedWords {
/** Looking for an equal sign state. */
protected static final int S_START_EQ = 0;
/** Looking for a question mark state. */
protected static final int S_START_QM = 1;
/** Reading the charset state. */
protected static final int S_CHARSET = 2;
/** Reading the encoding state. */
protected static final int S_ENCODING = 3;
/** Reading the encoded words state. */
protected static final int S_ENCODED_WORDS = 4;
/** Looking for the last equal sign state. */
protected static final int S_END_EQ = 5;
/** Base64 encoding id. */
public static final int ENC_BASE64 = 1;
/** Quoted-Printable encoding id. */
public static final int ENC_QUOTEDPRINTABLE = 2;
/** Control character characteristic. */
protected static final int CC_CONTROL = 1;
/** Separator character characteristic. */
protected static final int CC_SEPARATOR_WS = 2;
/** rfc2616 separator minus space and tab. */
protected static final String separators = "()<>@,;:\\\"/[]?={} \t";
/** Table of separator and control characters. */
protected static final byte[] charCharacteristicsTab = new byte[256];
/*
* Populate table with separator and control characters.
*/
static {
for (int i=0; i 0) {
try {
charset = Charset.forName(ew.charsetStr);
ew.bValidCharset = true;
} catch (IllegalCharsetNameException e) {
//System.err.println("ERROR IllegalCharsetNameException Charset: " + ew.charsetStr + " => " + e.getMessage());
charset = Charset.defaultCharset();
ew.bValidCharset = false;
} catch (UnsupportedCharsetException e) {
// System.err.println("ERROR UnsupportedCharsetException Charset: " + ew.charsetStr + " => " + e.getMessage());
charset = Charset.defaultCharset();
ew.bValidCharset = false;
}
state = S_ENCODING;
} else {
bLoop = false;
}
break;
default:
if (charCharacteristicsTab[c] == 0 && c < 127) {
sb.append((char) c);
} else {
bLoop = false;
}
break;
}
break;
case S_ENCODING:
switch (c) {
case -1:
case '\r':
case '\n':
bLoop = false;
break;
case '?':
ew.encodingStr = sb.toString().toUpperCase();
sb.setLength(0);
if (ew.encodingStr.length() > 0) {
if ("b".equalsIgnoreCase(ew.encodingStr)) {
ew.encoding = ENC_BASE64;
} else if ("q".equalsIgnoreCase(ew.encodingStr)) {
ew.encoding = ENC_QUOTEDPRINTABLE;
}
state = S_ENCODED_WORDS;
} else {
bLoop = false;
}
break;
default:
if (charCharacteristicsTab[c] == 0 && c < 127) {
sb.append((char) c);
} else {
bLoop = false;
}
break;
}
break;
case S_ENCODED_WORDS:
switch (c) {
case -1:
case '\r':
case '\n':
bLoop = false;
break;
case '?':
ew.encoded_text = sb.toString();
sb.setLength(0);
byte[] decoded = null;
if (ew.encoding == ENC_BASE64) {
decoded = Base64.decodeToArray(ew.encoded_text, true);
} else if (ew.encoding == ENC_QUOTEDPRINTABLE) {
decoded = QuotedPrintable.decode(ew.encoded_text);
} else {
// debug
//System.out.println("Encoding: " + ew.encodingStr);
}
if (decoded != null) {
ByteBuffer bb = ByteBuffer.wrap(decoded);
CharBuffer cb = CharBuffer.allocate(bb.capacity());
CharsetDecoder decoder = charset.newDecoder();
decoder.onMalformedInput(CodingErrorAction.REPORT);
decoder.onUnmappableCharacter(CodingErrorAction.REPORT);
try {
boolean bDecodeLoop = true;
while (bDecodeLoop) {
CoderResult result = decoder.decode(bb, cb, true);
sb.append(cb.array(), cb.arrayOffset(), cb.position());
cb.clear();
if (result == CoderResult.UNDERFLOW) {
bDecodeLoop = false;
} else if (result.isError()) {
bb.position(Math.min(bb.position() + result.length(), bb.limit()));
sb.append('?');
ew.bConversionError = true;
}
}
} catch (CoderMalfunctionError e) {
}
ew.decoded_text = sb.toString();
}
state = S_END_EQ;
break;
default:
if (c > 32 && c < 127) {
sb.append((char) c);
} else {
bLoop = false;
}
break;
}
break;
case S_END_EQ:
if (c == -1) {
bLoop = false;
} else if (c == '=') {
ew.bIsValid = true;
bLoop = false;
}
break;
}
}
ew.line = lineOut.toByteArray();
ew.bIsValid = ew.bIsValid & ew.bValidCharset & ew.encoding != 0 && ew.decoded_text != null;
return ew;
}
}
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