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 * http://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 package org.apache.camel.util;
018
019 import java.util.BitSet;
020
021 /**
022 * Encoder for unsafe URI characters.
023 * <p/>
024 * A good source for details is <a href="http://en.wikipedia.org/wiki/Url_encode">wikipedia url encode</a> article.
025 */
026 public final class UnsafeUriCharactersEncoder {
027 private static BitSet unsafeCharactersRfc1738;
028 private static BitSet unsafeCharactersHttp;
029 private static final char[] HEX_DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C',
030 'D', 'E', 'F', 'a', 'b', 'c', 'd', 'e', 'f'};
031
032 static {
033 unsafeCharactersRfc1738 = new BitSet(256);
034 unsafeCharactersRfc1738.set(' ');
035 unsafeCharactersRfc1738.set('"');
036 unsafeCharactersRfc1738.set('<');
037 unsafeCharactersRfc1738.set('>');
038 unsafeCharactersRfc1738.set('#');
039 unsafeCharactersRfc1738.set('%');
040 unsafeCharactersRfc1738.set('{');
041 unsafeCharactersRfc1738.set('}');
042 unsafeCharactersRfc1738.set('|');
043 unsafeCharactersRfc1738.set('\\');
044 unsafeCharactersRfc1738.set('^');
045 unsafeCharactersRfc1738.set('~');
046 unsafeCharactersRfc1738.set('[');
047 unsafeCharactersRfc1738.set(']');
048 unsafeCharactersRfc1738.set('`');
049 }
050
051 static {
052 unsafeCharactersHttp = new BitSet(256);
053 unsafeCharactersHttp.set(' ');
054 unsafeCharactersHttp.set('"');
055 unsafeCharactersHttp.set('<');
056 unsafeCharactersHttp.set('>');
057 unsafeCharactersHttp.set('#');
058 unsafeCharactersHttp.set('%');
059 unsafeCharactersHttp.set('{');
060 unsafeCharactersHttp.set('}');
061 unsafeCharactersHttp.set('|');
062 unsafeCharactersHttp.set('\\');
063 unsafeCharactersHttp.set('^');
064 unsafeCharactersHttp.set('~');
065 unsafeCharactersHttp.set('`');
066 }
067
068 private UnsafeUriCharactersEncoder() {
069 // util class
070 }
071
072 public static String encode(String s) {
073 return encode(s, unsafeCharactersRfc1738);
074 }
075
076 public static String encodeHttpURI(String s) {
077 return encode(s, unsafeCharactersHttp);
078 }
079
080 public static String encode(String s, BitSet unsafeCharacters) {
081 int n = s == null ? 0 : s.length();
082 if (n == 0) {
083 return s;
084 }
085
086 // First check whether we actually need to encode
087 char chars[] = s.toCharArray();
088 for (int i = 0;;) {
089 // just deal with the ascii character
090 if (chars[i] > 0 && chars[i] < 128) {
091 if (unsafeCharacters.get(chars[i])) {
092 break;
093 }
094 }
095 if (++i >= chars.length) {
096 return s;
097 }
098 }
099
100 // okay there are some unsafe characters so we do need to encode
101 // see details at: http://en.wikipedia.org/wiki/Url_encode
102 StringBuilder sb = new StringBuilder();
103 for (int i = 0; i < chars.length; i++) {
104 char ch = chars[i];
105 if (ch > 0 && ch < 128 && unsafeCharacters.get(ch)) {
106 // special for % sign as it may be a decimal encoded value
107 if (ch == '%') {
108 char next = i + 1 < chars.length ? chars[i + 1] : ' ';
109 char next2 = i + 2 < chars.length ? chars[i + 2] : ' ';
110
111 if (isHexDigit(next) && isHexDigit(next2)) {
112 // its already encoded (decimal encoded) so just append as is
113 sb.append(ch);
114 } else {
115 // must escape then, as its an unsafe character
116 appendEscape(sb, (byte)ch);
117 }
118 } else {
119 // must escape then, as its an unsafe character
120 appendEscape(sb, (byte)ch);
121 }
122 } else {
123 sb.append(ch);
124 }
125 }
126 return sb.toString();
127 }
128
129 private static void appendEscape(StringBuilder sb, byte b) {
130 sb.append('%');
131 sb.append(HEX_DIGITS[(b >> 4) & 0x0f]);
132 sb.append(HEX_DIGITS[(b >> 0) & 0x0f]);
133 }
134
135 private static boolean isHexDigit(char ch) {
136 for (char hex : HEX_DIGITS) {
137 if (hex == ch) {
138 return true;
139 }
140 }
141 return false;
142 }
143
144 }