org.apache.fop.datatypes.URISpecification Maven / Gradle / Ivy
/*
* 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.
*/
/* $Id: URISpecification.java 1806679 2017-08-30 08:43:06Z cbowditch $ */
package org.apache.fop.datatypes;
import java.io.UnsupportedEncodingException;
/**
* This class contains method to deal with the <uri-specification> datatype from XSL-FO.
*/
public final class URISpecification {
private URISpecification() {
}
/**
* Get the URL string from a wrapped URL.
*
* @param href the input wrapped URL
* @return the raw URL
*/
public static String getURL(String href) {
/*
* According to section 5.11 a is:
* "url(" + URI + ")"
* according to 7.28.7 a is:
* URI
* So handle both.
*/
href = href.trim();
if (href.startsWith("url(") && (href.indexOf(")") != -1)) {
href = href.substring(4, href.lastIndexOf(")")).trim();
if (href.startsWith("'") && href.endsWith("'")) {
href = href.substring(1, href.length() - 1);
} else if (href.startsWith("\"") && href.endsWith("\"")) {
href = href.substring(1, href.length() - 1);
}
} else {
// warn
}
return href;
}
private static final String PUNCT = ",;:$&+=";
private static final String RESERVED = PUNCT + "?/[]@";
/* not used
private static boolean isValidURIChar(char ch) {
return true;
}
*/
private static boolean isDigit(char ch) {
return (ch >= '0' && ch <= '9');
}
private static boolean isAlpha(char ch) {
return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z');
}
private static boolean isHexDigit(char ch) {
return (ch >= '0' && ch <= '9') || (ch >= 'A' && ch <= 'F') || (ch >= 'a' && ch <= 'f');
}
private static boolean isReserved(char ch) {
if (RESERVED.indexOf(ch) >= 0) {
return true;
} else if ('#' == ch) {
//# is not a reserved character but is used for the fragment
return true;
}
return false;
}
private static boolean isUnreserved(char ch) {
if (isDigit(ch) || isAlpha(ch)) {
return true;
} else if ("_-!.~\'()*".indexOf(ch) >= 0) {
//remaining unreserved characters
return true;
}
return false;
}
private static final char[] HEX_DIGITS = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
};
private static void appendEscape(StringBuffer sb, byte b) {
sb.append('%').append(HEX_DIGITS[(b >> 4) & 0x0f]).append(HEX_DIGITS[(b >> 0) & 0x0f]);
}
/**
* Escapes any illegal URI character in a given URI, for example, it escapes a space to "%20".
* Note: This method does not "parse" the URI and therefore does not treat the individual
* components (user-info, path, query etc.) individually.
* @param uri the URI to inspect
* @return the escaped URI
*/
public static String escapeURI(String uri) {
uri = getURL(uri);
StringBuffer sb = new StringBuffer();
for (int i = 0, c = uri.length(); i < c; i++) {
char ch = uri.charAt(i);
if (ch == '%') {
if (i < c - 3 && isHexDigit(uri.charAt(i + 1)) && isHexDigit(uri.charAt(i + 2))) {
sb.append(ch);
continue;
}
}
if (isReserved(ch) || isUnreserved(ch)) {
//Note: this may not be accurate for some very special cases.
sb.append(ch);
} else {
try {
byte[] utf8 = Character.toString(ch).getBytes("UTF-8");
for (byte anUtf8 : utf8) {
appendEscape(sb, anUtf8);
}
} catch (UnsupportedEncodingException e) {
throw new Error("Incompatible JVM. UTF-8 not supported.");
}
}
}
return sb.toString();
}
}