/*
* Copyright 2001-2004 The Apache Software Foundation.
*
* 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.apache.commons.codec.net;
import java.io.UnsupportedEncodingException;
import java.util.BitSet;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.EncoderException;
import org.apache.commons.codec.StringDecoder;
import org.apache.commons.codec.StringEncoder;
/**
* <p>
* Similar to the Quoted-Printable content-transfer-encoding defined in <a
* href="http://www.ietf.org/rfc/rfc1521.txt">RFC 1521</a> and designed to allow text containing mostly ASCII
* characters to be decipherable on an ASCII terminal without decoding.
* </p>
*
* <p>
* <a href="http://www.ietf.org/rfc/rfc1522.txt">RFC 1522</a> describes techniques to allow the encoding of non-ASCII
* text in various portions of a RFC 822 [2] message header, in a manner which is unlikely to confuse existing message
* handling software.
* </p>
*
* @see <a href="http://www.ietf.org/rfc/rfc1522.txt">MIME (Multipurpose Internet Mail Extensions) Part Two: Message
* Header Extensions for Non-ASCII Text</a>
*
* @author Apache Software Foundation
* @since 1.3
* @version $Id: QCodec.java,v 1.6 2004/05/24 00:24:32 ggregory Exp $
*/
public class QCodec extends RFC1522Codec implements StringEncoder, StringDecoder {
/**
* The default charset used for string decoding and encoding.
*/
private String charset = StringEncodings.UTF8;
/**
* BitSet of printable characters as defined in RFC 1522.
*/
private static final BitSet PRINTABLE_CHARS = new BitSet(256);
// Static initializer for printable chars collection
static {
// alpha characters
PRINTABLE_CHARS.set(' ');
PRINTABLE_CHARS.set('!');
PRINTABLE_CHARS.set('"');
PRINTABLE_CHARS.set('#');
PRINTABLE_CHARS.set('$');
PRINTABLE_CHARS.set('%');
PRINTABLE_CHARS.set('&');
PRINTABLE_CHARS.set('\'');
PRINTABLE_CHARS.set('(');
PRINTABLE_CHARS.set(')');
PRINTABLE_CHARS.set('*');
PRINTABLE_CHARS.set('+');
PRINTABLE_CHARS.set(',');
PRINTABLE_CHARS.set('-');
PRINTABLE_CHARS.set('.');
PRINTABLE_CHARS.set('/');
for (int i = '0'; i <= '9'; i++) {
PRINTABLE_CHARS.set(i);
}
PRINTABLE_CHARS.set(':');
PRINTABLE_CHARS.set(';');
PRINTABLE_CHARS.set('<');
PRINTABLE_CHARS.set('>');
PRINTABLE_CHARS.set('@');
for (int i = 'A'; i <= 'Z'; i++) {
PRINTABLE_CHARS.set(i);
}
PRINTABLE_CHARS.set('[');
PRINTABLE_CHARS.set('\\');
PRINTABLE_CHARS.set(']');
PRINTABLE_CHARS.set('^');
PRINTABLE_CHARS.set('`');
for (int i = 'a'; i <= 'z'; i++) {
PRINTABLE_CHARS.set(i);
}
PRINTABLE_CHARS.set('{');
PRINTABLE_CHARS.set('|');
PRINTABLE_CHARS.set('}');
PRINTABLE_CHARS.set('~');
}
private static byte BLANK = 32;
private static byte UNDERSCORE = 95;
private boolean encodeBlanks = false;
/**
* Default constructor.
*/
public QCodec() {
super();
}
/**
* Constructor which allows for the selection of a default charset
*
* @param charset
* the default string charset to use.
*
* @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
* encoding names</a>
*/
public QCodec(final String charset) {
super();
this.charset = charset;
}
protected String getEncoding() {
return "Q";
}
protected byte[] doEncoding(byte[] bytes) throws EncoderException {
if (bytes == null) {
return null;
}
byte[] data = QuotedPrintableCodec.encodeQuotedPrintable(PRINTABLE_CHARS, bytes);
if (this.encodeBlanks) {
for (int i = 0; i < data.length; i++) {
if (data[i] == BLANK) {
data[i] = UNDERSCORE;
}
}
}
return data;
}
protected byte[] doDecoding(byte[] bytes) throws DecoderException {
if (bytes == null) {
return null;
}
boolean hasUnderscores = false;
for (int i = 0; i < bytes.length; i++) {
if (bytes[i] == UNDERSCORE) {
hasUnderscores = true;
break;
}
}
if (hasUnderscores) {
byte[] tmp = new byte[bytes.length];
for (int i = 0; i < bytes.length; i++) {
byte b = bytes[i];
if (b != UNDERSCORE) {
tmp[i] = b;
} else {
tmp[i] = BLANK;
}
}
return QuotedPrintableCodec.decodeQuotedPrintable(tmp);
}
return QuotedPrintableCodec.decodeQuotedPrintable(bytes);
}
/**
* Encodes a string into its quoted-printable form using the specified charset. Unsafe characters are escaped.
*
* @param pString
* string to convert to quoted-printable form
* @param charset
* the charset for pString
* @return quoted-printable string
*
* @throws EncoderException
* thrown if a failure condition is encountered during the encoding process.
*/
public String encode(final String pString, final String charset) throws EncoderException {
if (pString == null) {
return null;
}
try {
return encodeText(pString, charset);
} catch (UnsupportedEncodingException e) {
throw new EncoderException(e.getMessage());
}
}
/**
* Encodes a string into its quoted-printable form using the default charset. Unsafe characters are escaped.
*
* @param pString
* string to convert to quoted-printable form
* @return quoted-printable string
*
* @throws EncoderException
* thrown if a failure condition is encountered during the encoding process.
*/
public String encode(String pString) throws EncoderException {
if (pString == null) {
return null;
}
return encode(pString, getDefaultCharset());
}
/**
* Decodes a quoted-printable string into its original form. Escaped characters are converted back to their original
* representation.
*
* @param pString
* quoted-printable string to convert into its original form
*
* @return original string
*
* @throws DecoderException
* A decoder exception is thrown if a failure condition is encountered during the decode process.
*/
public String decode(String pString) throws DecoderException {
if (pString == null) {
return null;
}
try {
return decodeText(pString);
} catch (UnsupportedEncodingException e) {
throw new DecoderException(e.getMessage());
}
}
/**
* Encodes an object into its quoted-printable form using the default charset. Unsafe characters are escaped.
*
* @param pObject
* object to convert to quoted-printable form
* @return quoted-printable object
*
* @throws EncoderException
* thrown if a failure condition is encountered during the encoding process.
*/
public Object encode(Object pObject) throws EncoderException {
if (pObject == null) {
return null;
} else if (pObject instanceof String) {
return encode((String) pObject);
} else {
throw new EncoderException("Objects of type "
+ pObject.getClass().getName()
+ " cannot be encoded using Q codec");
}
}
/**
* Decodes a quoted-printable object into its original form. Escaped characters are converted back to their original
* representation.
*
* @param pObject
* quoted-printable object to convert into its original form
*
* @return original object
*
* @throws DecoderException
* A decoder exception is thrown if a failure condition is encountered during the decode process.
*/
public Object decode(Object pObject) throws DecoderException {
if (pObject == null) {
return null;
} else if (pObject instanceof String) {
return decode((String) pObject);
} else {
throw new DecoderException("Objects of type "
+ pObject.getClass().getName()
+ " cannot be decoded using Q codec");
}
}
/**
* The default charset used for string decoding and encoding.
*
* @return the default string charset.
*/
public String getDefaultCharset() {
return this.charset;
}
/**
* Tests if optional tranformation of SPACE characters is to be used
*
* @return <code>true</code> if SPACE characters are to be transformed, <code>false</code> otherwise
*/
public boolean isEncodeBlanks() {
return this.encodeBlanks;
}
/**
* Defines whether optional tranformation of SPACE characters is to be used
*
* @param b
* <code>true</code> if SPACE characters are to be transformed, <code>false</code> otherwise
*/
public void setEncodeBlanks(boolean b) {
this.encodeBlanks = b;
}
}
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