/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;
import java.util.BitSet;
import org.apache.commons.codec.BinaryDecoder;
import org.apache.commons.codec.BinaryEncoder;
import org.apache.commons.codec.CharEncoding;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.EncoderException;
import org.apache.commons.codec.StringDecoder;
import org.apache.commons.codec.StringEncoder;
import org.apache.commons.codec.binary.StringUtils;
/**
* Implements the 'www-form-urlencoded' encoding scheme, also misleadingly known as URL encoding.
* <p>
* This codec is meant to be a replacement for standard Java classes {@link java.net.URLEncoder} and
* {@link java.net.URLDecoder} on older Java platforms, as these classes in Java versions below
* 1.4 rely on the platform's default charset encoding.
* <p>
* This class is immutable and thread-safe.
*
* @see <a href="http://www.w3.org/TR/html4/interact/forms.html#h-17.13.4.1">Chapter 17.13.4 Form content types</a>
* of the <a href="http://www.w3.org/TR/html4/">HTML 4.01 Specification<a>
*
* @since 1.2
* @version $Id: URLCodec.java 1462705 2013-03-30 05:22:40Z ggregory $
*/
public class URLCodec implements BinaryEncoder, BinaryDecoder, StringEncoder, StringDecoder {
/**
* Radix used in encoding and decoding.
*/
static final int RADIX = 16;
/**
* The default charset used for string decoding and encoding.
*
* @deprecated TODO: This field will be changed to a private final Charset in 2.0.
*/
@Deprecated
protected String charset;
/**
* Release 1.5 made this field final.
*/
protected static final byte ESCAPE_CHAR = '%';
/**
* BitSet of www-form-url safe characters.
*/
protected static final BitSet WWW_FORM_URL = new BitSet(256);
// Static initializer for www_form_url
static {
// alpha characters
for (int i = 'a'; i <= 'z'; i++) {
WWW_FORM_URL.set(i);
}
for (int i = 'A'; i <= 'Z'; i++) {
WWW_FORM_URL.set(i);
}
// numeric characters
for (int i = '0'; i <= '9'; i++) {
WWW_FORM_URL.set(i);
}
// special chars
WWW_FORM_URL.set('-');
WWW_FORM_URL.set('_');
WWW_FORM_URL.set('.');
WWW_FORM_URL.set('*');
// blank to be replaced with +
WWW_FORM_URL.set(' ');
}
/**
* Default constructor.
*/
public URLCodec() {
this(CharEncoding.UTF_8);
}
/**
* Constructor which allows for the selection of a default charset.
*
* @param charset the default string charset to use.
*/
public URLCodec(final String charset) {
super();
this.charset = charset;
}
/**
* Encodes an array of bytes into an array of URL safe 7-bit characters. Unsafe characters are escaped.
*
* @param urlsafe
* bitset of characters deemed URL safe
* @param bytes
* array of bytes to convert to URL safe characters
* @return array of bytes containing URL safe characters
*/
public static final byte[] encodeUrl(BitSet urlsafe, final byte[] bytes) {
if (bytes == null) {
return null;
}
if (urlsafe == null) {
urlsafe = WWW_FORM_URL;
}
final ByteArrayOutputStream buffer = new ByteArrayOutputStream();
for (final byte c : bytes) {
int b = c;
if (b < 0) {
b = 256 + b;
}
if (urlsafe.get(b)) {
if (b == ' ') {
b = '+';
}
buffer.write(b);
} else {
buffer.write(ESCAPE_CHAR);
final char hex1 = Character.toUpperCase(Character.forDigit((b >> 4) & 0xF, RADIX));
final char hex2 = Character.toUpperCase(Character.forDigit(b & 0xF, RADIX));
buffer.write(hex1);
buffer.write(hex2);
}
}
return buffer.toByteArray();
}
/**
* Decodes an array of URL safe 7-bit characters into an array of original bytes. Escaped characters are converted
* back to their original representation.
*
* @param bytes
* array of URL safe characters
* @return array of original bytes
* @throws DecoderException
* Thrown if URL decoding is unsuccessful
*/
public static final byte[] decodeUrl(final byte[] bytes) throws DecoderException {
if (bytes == null) {
return null;
}
final ByteArrayOutputStream buffer = new ByteArrayOutputStream();
for (int i = 0; i < bytes.length; i++) {
final int b = bytes[i];
if (b == '+') {
buffer.write(' ');
} else if (b == ESCAPE_CHAR) {
try {
final int u = Utils.digit16(bytes[++i]);
final int l = Utils.digit16(bytes[++i]);
buffer.write((char) ((u << 4) + l));
} catch (final ArrayIndexOutOfBoundsException e) {
throw new DecoderException("Invalid URL encoding: ", e);
}
} else {
buffer.write(b);
}
}
return buffer.toByteArray();
}
/**
* Encodes an array of bytes into an array of URL safe 7-bit characters. Unsafe characters are escaped.
*
* @param bytes
* array of bytes to convert to URL safe characters
* @return array of bytes containing URL safe characters
*/
@Override
public byte[] encode(final byte[] bytes) {
return encodeUrl(WWW_FORM_URL, bytes);
}
/**
* Decodes an array of URL safe 7-bit characters into an array of original bytes. Escaped characters are converted
* back to their original representation.
*
* @param bytes
* array of URL safe characters
* @return array of original bytes
* @throws DecoderException
* Thrown if URL decoding is unsuccessful
*/
@Override
public byte[] decode(final byte[] bytes) throws DecoderException {
return decodeUrl(bytes);
}
/**
* Encodes a string into its URL safe form using the specified string charset. Unsafe characters are escaped.
*
* @param str
* string to convert to a URL safe form
* @param charset
* the charset for str
* @return URL safe string
* @throws UnsupportedEncodingException
* Thrown if charset is not supported
*/
public String encode(final String str, final String charset) throws UnsupportedEncodingException {
if (str == null) {
return null;
}
return StringUtils.newStringUsAscii(encode(str.getBytes(charset)));
}
/**
* Encodes a string into its URL safe form using the default string charset. Unsafe characters are escaped.
*
* @param str
* string to convert to a URL safe form
* @return URL safe string
* @throws EncoderException
* Thrown if URL encoding is unsuccessful
*
* @see #getDefaultCharset()
*/
@Override
public String encode(final String str) throws EncoderException {
if (str == null) {
return null;
}
try {
return encode(str, getDefaultCharset());
} catch (final UnsupportedEncodingException e) {
throw new EncoderException(e.getMessage(), e);
}
}
/**
* Decodes a URL safe string into its original form using the specified encoding. Escaped characters are converted
* back to their original representation.
*
* @param str
* URL safe string to convert into its original form
* @param charset
* the original string charset
* @return original string
* @throws DecoderException
* Thrown if URL decoding is unsuccessful
* @throws UnsupportedEncodingException
* Thrown if charset is not supported
*/
public String decode(final String str, final String charset) throws DecoderException, UnsupportedEncodingException {
if (str == null) {
return null;
}
return new String(decode(StringUtils.getBytesUsAscii(str)), charset);
}
/**
* Decodes a URL safe string into its original form using the default string charset. Escaped characters are
* converted back to their original representation.
*
* @param str
* URL safe string to convert into its original form
* @return original string
* @throws DecoderException
* Thrown if URL decoding is unsuccessful
* @see #getDefaultCharset()
*/
@Override
public String decode(final String str) throws DecoderException {
if (str == null) {
return null;
}
try {
return decode(str, getDefaultCharset());
} catch (final UnsupportedEncodingException e) {
throw new DecoderException(e.getMessage(), e);
}
}
/**
* Encodes an object into its URL safe form. Unsafe characters are escaped.
*
* @param obj
* string to convert to a URL safe form
* @return URL safe object
* @throws EncoderException
* Thrown if URL encoding is not applicable to objects of this type or if encoding is unsuccessful
*/
@Override
public Object encode(final Object obj) throws EncoderException {
if (obj == null) {
return null;
} else if (obj instanceof byte[]) {
return encode((byte[])obj);
} else if (obj instanceof String) {
return encode((String)obj);
} else {
throw new EncoderException("Objects of type " + obj.getClass().getName() + " cannot be URL encoded");
}
}
/**
* Decodes a URL safe object into its original form. Escaped characters are converted back to their original
* representation.
*
* @param obj
* URL safe object to convert into its original form
* @return original object
* @throws DecoderException
* Thrown if the argument is not a <code>String</code> or <code>byte[]</code>. Thrown if a failure
* condition is encountered during the decode process.
*/
@Override
public Object decode(final Object obj) throws DecoderException {
if (obj == null) {
return null;
} else if (obj instanceof byte[]) {
return decode((byte[]) obj);
} else if (obj instanceof String) {
return decode((String) obj);
} else {
throw new DecoderException("Objects of type " + obj.getClass().getName() + " cannot be URL decoded");
}
}
/**
* The default charset used for string decoding and encoding.
*
* @return the default string charset.
*/
public String getDefaultCharset() {
return this.charset;
}
/**
* The <code>String</code> encoding used for decoding and encoding.
*
* @return Returns the encoding.
*
* @deprecated Use {@link #getDefaultCharset()}, will be removed in 2.0.
*/
@Deprecated
public String getEncoding() {
return this.charset;
}
}