Source code
Description: source: package: org.apache.commons.codec.net, class: URLCodec

    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      https://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.codec.net;
    019
    020import java.io.ByteArrayOutputStream;
    021import java.io.UnsupportedEncodingException;
    022import java.net.URLDecoder;
    023import java.net.URLEncoder;
    024import java.util.BitSet;
    025
    026import org.apache.commons.codec.BinaryDecoder;
    027import org.apache.commons.codec.BinaryEncoder;
    028import org.apache.commons.codec.CharEncoding;
    029import org.apache.commons.codec.DecoderException;
    030import org.apache.commons.codec.EncoderException;
    031import org.apache.commons.codec.StringDecoder;
    032import org.apache.commons.codec.StringEncoder;
    033import org.apache.commons.codec.binary.StringUtils;
    034
    035/**
    036 * Implements the 'www-form-urlencoded' encoding scheme, also misleadingly known as URL encoding.
    037 * <p>
    038 * This codec is meant to be a replacement for standard Java classes {@link URLEncoder} and
    039 * {@link URLDecoder} on older Java platforms, as these classes in Java versions below
    040 * 1.4 rely on the platform's default charset encoding.
    041 * </p>
    042 * <p>
    043 * This class is thread-safe as of 1.11
    044 * </p>
    045 *
    046 * @see <a href="https://www.w3.org/TR/html4/interact/forms.html#h-17.13.4.1">Chapter 17.13.4 Form content types</a>
    047 *           of the <a href="https://www.w3.org/TR/html4/">HTML 4.01 Specification</a>
    048 *
    049 * @since 1.2
    050 */
    051public class URLCodec implements BinaryEncoder, BinaryDecoder, StringEncoder, StringDecoder {
    052
    053    /**
    054     * Release 1.5 made this field final.
    055     */
    056    protected static final byte ESCAPE_CHAR = '%';
    057
    058    private static final byte PLUS_CHAR = '+';
    059
    060    /**
    061     * BitSet of www-form-url safe characters.
    062     * This is a copy of the internal BitSet which is now used for the conversion.
    063     * Changes to this field are ignored.
    064     *
    065     * @deprecated 1.11 Will be removed in 2.0 (CODEC-230)
    066     */
    067    @Deprecated
    068    protected static final BitSet WWW_FORM_URL;
    069
    070    private static final BitSet WWW_FORM_URL_SAFE = new BitSet(256);
    071
    072    // Static initializer for www_form_url
    073    static {
    074        // alpha characters
    075        for (int i = 'a'; i <= 'z'; i++) {
    076            WWW_FORM_URL_SAFE.set(i);
    077        }
    078        for (int i = 'A'; i <= 'Z'; i++) {
    079            WWW_FORM_URL_SAFE.set(i);
    080        }
    081        // numeric characters
    082        for (int i = '0'; i <= '9'; i++) {
    083            WWW_FORM_URL_SAFE.set(i);
    084        }
    085        // special chars
    086        WWW_FORM_URL_SAFE.set('-');
    087        WWW_FORM_URL_SAFE.set('_');
    088        WWW_FORM_URL_SAFE.set('.');
    089        WWW_FORM_URL_SAFE.set('*');
    090        // blank to be replaced with +
    091        WWW_FORM_URL_SAFE.set(' ');
    092
    093        // Create a copy in case anyone (ab)uses it
    094        WWW_FORM_URL = (BitSet) WWW_FORM_URL_SAFE.clone();
    095    }
    096
    097    /**
    098     * Decodes an array of URL safe 7-bit characters into an array of original bytes. Escaped characters are converted
    099     * back to their original representation.
    100     *
    101     * @param bytes
    102     *            array of URL safe characters.
    103     * @return array of original bytes.
    104     * @throws DecoderException
    105     *             Thrown if URL decoding is unsuccessful.
    106     */
    107    public static final byte[] decodeUrl(final byte[] bytes) throws DecoderException {
    108        if (bytes == null) {
    109            return null;
    110        }
    111        final ByteArrayOutputStream buffer = new ByteArrayOutputStream();
    112        for (int i = 0; i < bytes.length; i++) {
    113            final int b = bytes[i];
    114            if (b == PLUS_CHAR) {
    115                buffer.write(' ');
    116            } else if (b == ESCAPE_CHAR) {
    117                try {
    118                    final int u = Utils.digit16(bytes[++i]);
    119                    final int l = Utils.digit16(bytes[++i]);
    120                    buffer.write((char) ((u << 4) + l));
    121                } catch (final ArrayIndexOutOfBoundsException e) {
    122                    throw new DecoderException("Invalid URL encoding: ", e);
    123                }
    124            } else {
    125                buffer.write(b);
    126            }
    127        }
    128        return buffer.toByteArray();
    129    }
    130
    131    /**
    132     * Encodes an array of bytes into an array of URL safe 7-bit characters. Unsafe characters are escaped.
    133     * The characters {@code %} and {@code +} are always escaped because {@link #decodeUrl(byte[])}
    134     * treats them as URL-encoding syntax.
    135     *
    136     * @param urlsafe
    137     *            bitset of characters deemed URL safe, except for {@code %} and {@code +}.
    138     * @param bytes
    139     *            array of bytes to convert to URL safe characters.
    140     * @return array of bytes containing URL safe characters.
    141     */
    142    public static final byte[] encodeUrl(BitSet urlsafe, final byte[] bytes) {
    143        if (bytes == null) {
    144            return null;
    145        }
    146        if (urlsafe == null) {
    147            urlsafe = WWW_FORM_URL_SAFE;
    148        }
    149
    150        final ByteArrayOutputStream buffer = new ByteArrayOutputStream();
    151        for (final byte c : bytes) {
    152            int b = c;
    153            if (b < 0) {
    154                b = 256 + b;
    155            }
    156            if (urlsafe.get(b) && b != ESCAPE_CHAR && b != PLUS_CHAR) {
    157                if (b == ' ') {
    158                    b = PLUS_CHAR;
    159                }
    160                buffer.write(b);
    161            } else {
    162                buffer.write(ESCAPE_CHAR);
    163                final char hex1 = Utils.hexChar(b >> 4);
    164                final char hex2 = Utils.hexChar(b);
    165                buffer.write(hex1);
    166                buffer.write(hex2);
    167            }
    168        }
    169        return buffer.toByteArray();
    170    }
    171
    172    /**
    173     * The default charset used for string decoding and encoding.
    174     *
    175     * @deprecated TODO: This field will be changed to a private final Charset in 2.0. (CODEC-126)
    176     */
    177    @Deprecated
    178    protected volatile String charset; // added volatile: see CODEC-232
    179
    180    /**
    181     * Default constructor.
    182     */
    183    public URLCodec() {
    184        this(CharEncoding.UTF_8);
    185    }
    186
    187    /**
    188     * Constructs a new instance for the selection of a default charset.
    189     *
    190     * @param charset The default string charset to use.
    191     */
    192    public URLCodec(final String charset) {
    193        this.charset = charset;
    194    }
    195
    196    /**
    197     * Decodes an array of URL safe 7-bit characters into an array of original bytes. Escaped characters are converted
    198     * back to their original representation.
    199     *
    200     * @param bytes
    201     *            array of URL safe characters.
    202     * @return array of original bytes.
    203     * @throws DecoderException
    204     *             Thrown if URL decoding is unsuccessful.
    205     */
    206    @Override
    207    public byte[] decode(final byte[] bytes) throws DecoderException {
    208        return decodeUrl(bytes);
    209    }
    210
    211    /**
    212     * Decodes a URL safe object into its original form. Escaped characters are converted back to their original
    213     * representation.
    214     *
    215     * @param obj
    216     *            URL safe object to convert into its original form.
    217     * @return original object.
    218     * @throws DecoderException
    219     *             Thrown if the argument is not a {@code String} or {@code byte[]}. Thrown if a failure
    220     *             condition is encountered during the decode process.
    221     */
    222    @Override
    223    public Object decode(final Object obj) throws DecoderException {
    224        if (obj == null) {
    225            return null;
    226        }
    227        if (obj instanceof byte[]) {
    228            return decode((byte[]) obj);
    229        }
    230        if (obj instanceof String) {
    231            return decode((String) obj);
    232        }
    233        throw new DecoderException("Objects of type " + obj.getClass().getName() + " cannot be URL decoded");
    234    }
    235
    236    /**
    237     * Decodes a URL safe string into its original form using the default string charset. Escaped characters are
    238     * converted back to their original representation.
    239     *
    240     * @param str
    241     *            URL safe string to convert into its original form.
    242     * @return original string.
    243     * @throws DecoderException
    244     *             Thrown if URL decoding is unsuccessful.
    245     * @see #getDefaultCharset()
    246     */
    247    @Override
    248    public String decode(final String str) throws DecoderException {
    249        if (str == null) {
    250            return null;
    251        }
    252        try {
    253            return decode(str, getDefaultCharset());
    254        } catch (final UnsupportedEncodingException e) {
    255            throw new DecoderException(e.getMessage(), e);
    256        }
    257    }
    258
    259    /**
    260     * Decodes a URL safe string into its original form using the specified encoding. Escaped characters are converted
    261     * back to their original representation.
    262     *
    263     * @param str
    264     *            URL safe string to convert into its original form.
    265     * @param charsetName
    266     *            the original string charset.
    267     * @return original string.
    268     * @throws DecoderException
    269     *             Thrown if URL decoding is unsuccessful.
    270     * @throws UnsupportedEncodingException
    271     *             Thrown if charset is not supported.
    272     */
    273    public String decode(final String str, final String charsetName)
    274            throws DecoderException, UnsupportedEncodingException {
    275        if (str == null) {
    276            return null;
    277        }
    278        return new String(decode(StringUtils.getBytesUsAscii(str)), charsetName);
    279    }
    280
    281    /**
    282     * Encodes an array of bytes into an array of URL safe 7-bit characters. Unsafe characters are escaped.
    283     *
    284     * @param bytes
    285     *            array of bytes to convert to URL safe characters.
    286     * @return array of bytes containing URL safe characters.
    287     */
    288    @Override
    289    public byte[] encode(final byte[] bytes) {
    290        return encodeUrl(WWW_FORM_URL_SAFE, bytes);
    291    }
    292
    293    /**
    294     * Encodes an object into its URL safe form. Unsafe characters are escaped.
    295     *
    296     * @param obj
    297     *            string to convert to a URL safe form.
    298     * @return URL safe object.
    299     * @throws EncoderException
    300     *             Thrown if URL encoding is not applicable to objects of this type or if encoding is unsuccessful.
    301     */
    302    @Override
    303    public Object encode(final Object obj) throws EncoderException {
    304        if (obj == null) {
    305            return null;
    306        }
    307        if (obj instanceof byte[]) {
    308            return encode((byte[]) obj);
    309        }
    310        if (obj instanceof String) {
    311            return encode((String) obj);
    312        }
    313        throw new EncoderException("Objects of type " + obj.getClass().getName() + " cannot be URL encoded");
    314    }
    315
    316    /**
    317     * Encodes a string into its URL safe form using the default string charset. Unsafe characters are escaped.
    318     *
    319     * @param str
    320     *            string to convert to a URL safe form.
    321     * @return URL safe string.
    322     * @throws EncoderException
    323     *             Thrown if URL encoding is unsuccessful.
    324     * @see #getDefaultCharset()
    325     */
    326    @Override
    327    public String encode(final String str) throws EncoderException {
    328        if (str == null) {
    329            return null;
    330        }
    331        try {
    332            return encode(str, getDefaultCharset());
    333        } catch (final UnsupportedEncodingException e) {
    334            throw new EncoderException(e.getMessage(), e);
    335        }
    336    }
    337
    338    /**
    339     * Encodes a string into its URL safe form using the specified string charset. Unsafe characters are escaped.
    340     *
    341     * @param str
    342     *            string to convert to a URL safe form.
    343     * @param charsetName
    344     *            the charset for str.
    345     * @return URL safe string.
    346     * @throws UnsupportedEncodingException
    347     *             Thrown if charset is not supported.
    348     */
    349    public String encode(final String str, final String charsetName) throws UnsupportedEncodingException {
    350        if (str == null) {
    351            return null;
    352        }
    353        return StringUtils.newStringUsAscii(encode(str.getBytes(charsetName)));
    354    }
    355
    356    /**
    357     * The default charset used for string decoding and encoding.
    358     *
    359     * @return The default string charset.
    360     */
    361    public String getDefaultCharset() {
    362        return this.charset;
    363    }
    364
    365    /**
    366     * The {@code String} encoding used for decoding and encoding.
    367     *
    368     * @return The encoding.
    369     * @deprecated Use {@link #getDefaultCharset()}, will be removed in 2.0.
    370     */
    371    @Deprecated
    372    public String getEncoding() {
    373        return this.charset;
    374    }
    375
    376}