/*
* 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.
*/
/*
* Imported by CG 20090319 based on Apache Harmony ("enhanced") revision 493040.
*/
package java.net;
import java.io.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;
/**
* This class is used to encode a string using the format required by
* <code>application/x-www-form-urlencoded</code> MIME content type.
*
* It contains helper methods used by the URI class, and performs encoding and
* decoding in a slightly different way than URLEncoder and URLDecoder.
*/
class URIEncoderDecoder {
static final String digits = "0123456789ABCDEF"; //$NON-NLS-1$
static final String encoding = "UTF8"; //$NON-NLS-1$
/**
* Validate a string by checking if it contains any characters other than:
*
* 1. letters ('a'..'z', 'A'..'Z') 2. numbers ('0'..'9') 3. characters in
* the legalset parameter 4. others (Unicode characters that are not in
* US-ASCII set, and are not ISO Control or are not ISO Space characters)
* <p>
* called from URI.Helper.parseURI() to validate each component
* <p>
*
* @param s
* java.lang.String the string to be validated
* @param legal
* java.lang.String the characters allowed in the String s
*
*/
static void validate(String s, String legal) throws URISyntaxException {
for (int i = 0; i < s.length();) {
char ch = s.charAt(i);
if (ch == '%') {
do {
if (i + 2 >= s.length()) {
throw new URISyntaxException(s, "Incomplete % sequence", i);
}
int d1 = Character.digit(s.charAt(i + 1), 16);
int d2 = Character.digit(s.charAt(i + 2), 16);
if (d1 == -1 || d2 == -1) {
throw new URISyntaxException(s, "Invalid % sequence (" +
s.substring(i, i + 3) + ")", i);
}
i += 3;
} while (i < s.length() && s.charAt(i) == '%');
continue;
}
if (!((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')
|| (ch >= '0' && ch <= '9') || legal.indexOf(ch) > -1 || (ch > 127
&& !Character.isSpaceChar(ch) && !Character
.isISOControl(ch)))) {
throw new URISyntaxException(s, "Illegal character");
}
i++;
}
}
static void validateSimple(String s, String legal)
throws URISyntaxException {
for (int i = 0; i < s.length();) {
char ch = s.charAt(i);
if (!((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')
|| (ch >= '0' && ch <= '9') || legal.indexOf(ch) > -1)) {
throw new URISyntaxException(s, "Illegal character", i);
}
i++;
}
}
/**
* All characters except letters ('a'..'z', 'A'..'Z') and numbers ('0'..'9')
* and legal characters are converted into their hexidecimal value prepended
* by '%'.
* <p>
* For example: '#' -> %23
* <p>
* Other characters, which are Unicode chars that are not US-ASCII, and are
* not ISO Control or are not ISO Space chars, are preserved.
* <p>
* Called from URI.quoteComponent() (for multiple argument constructors)
* <p>
*
* @param s
* java.lang.String the string to be converted
* @param legal
* java.lang.String the characters allowed to be preserved in the
* string s
* @return java.lang.String the converted string
*/
static String quoteIllegal(String s, String legal)
throws UnsupportedEncodingException {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < s.length(); i++) {
char ch = s.charAt(i);
if ((ch >= 'a' && ch <= 'z')
|| (ch >= 'A' && ch <= 'Z')
|| (ch >= '0' && ch <= '9')
|| legal.indexOf(ch) > -1
|| (ch > 127 && !Character.isSpaceChar(ch) && !Character
.isISOControl(ch))) {
buf.append(ch);
} else {
byte[] bytes = new String(new char[] { ch }).getBytes(encoding);
for (int j = 0; j < bytes.length; j++) {
buf.append('%');
buf.append(digits.charAt((bytes[j] & 0xf0) >> 4));
buf.append(digits.charAt(bytes[j] & 0xf));
}
}
}
return buf.toString();
}
/**
* Other characters, which are Unicode chars that are not US-ASCII, and are
* not ISO Control or are not ISO Space chars are not preserved. They are
* converted into their hexidecimal value prepended by '%'.
* <p>
* For example: Euro currency symbol -> "%E2%82%AC".
* <p>
* Called from URI.toASCIIString()
* <p>
*
* @param s
* java.lang.String the string to be converted
* @return java.lang.String the converted string
*/
static String encodeOthers(String s) throws UnsupportedEncodingException {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < s.length(); i++) {
char ch = s.charAt(i);
if (ch <= 127) {
buf.append(ch);
} else {
byte[] bytes = new String(new char[] { ch }).getBytes(encoding);
for (int j = 0; j < bytes.length; j++) {
buf.append('%');
buf.append(digits.charAt((bytes[j] & 0xf0) >> 4));
buf.append(digits.charAt(bytes[j] & 0xf));
}
}
}
return buf.toString();
}
/**
* Decodes the string argument which is assumed to be encoded in the
* <code>x-www-form-urlencoded</code> MIME content type using the UTF-8
* encoding scheme.
* <p>
* '%' and two following hex digit characters are converted to the
* equivalent byte value. All other characters are passed through
* unmodified.
*
* <p>
* e.g. "A%20B%20C %24%25" -> "A B C $%"
* <p>
* Called from URI.getXYZ() methods
* <p>
*
* @param s
* java.lang.String The encoded string.
* @return java.lang.String The decoded version.
*/
static String decode(String s) throws UnsupportedEncodingException {
StringBuffer result = new StringBuffer();
ByteArrayOutputStream out = new ByteArrayOutputStream();
for (int i = 0; i < s.length();) {
char c = s.charAt(i);
if (c == '%') {
out.reset();
do {
if (i + 2 >= s.length()) {
throw new IllegalArgumentException("Incomplete % sequence at: " + i);
}
int d1 = Character.digit(s.charAt(i + 1), 16);
int d2 = Character.digit(s.charAt(i + 2), 16);
if (d1 == -1 || d2 == -1) {
throw new IllegalArgumentException("Invalid % sequence (" +
s.substring(i, i + 3) + ") at: " +
String.valueOf(i));
}
out.write((byte) ((d1 << 4) + d2));
i += 3;
} while (i < s.length() && s.charAt(i) == '%');
result.append(out.toString(encoding));
continue;
}
result.append(c);
i++;
}
return result.toString();
}
}