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Jetspeed-2 Portal Components
/*
* 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.jetspeed.util;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import org.apache.jetspeed.portlet.HeadElement;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* HeadElementUtils
*
* @version $Id: HeadElementUtils.java 881257 2009-11-17 12:53:41Z woonsan $
*/
public class HeadElementUtils
{
private static final int HEX = 16;
private static final String[] KNOWN_ENTITIES = {"gt", "amp", "lt", "apos", "quot"};
private static final Set EXPANDABLE_HEAD_ELEMENT_TAG_NAME_SET =
new HashSet(Arrays.asList(new String [] { "SCRIPT", "STYLE", "TITLE" } ));
private static final Set PREFORMATTED_HEAD_ELEMENT_TAG_NAME_SET =
new HashSet(Arrays.asList(new String [] { "SCRIPT", "STYLE" } ));
private static Logger log = LoggerFactory.getLogger(HeadElementUtils.class);
private HeadElementUtils()
{
}
public static String toHtmlString(final HeadElement headElement)
{
String tagName = headElement.getTagName().toUpperCase();
boolean isExpanedEmptyElements = EXPANDABLE_HEAD_ELEMENT_TAG_NAME_SET.contains(tagName);
boolean isPreformattedTextContent = PREFORMATTED_HEAD_ELEMENT_TAG_NAME_SET.contains(tagName);
return toString(headElement, isExpanedEmptyElements, isPreformattedTextContent, false);
}
public static String toXhtmlString(final HeadElement headElement)
{
String tagName = headElement.getTagName().toUpperCase();
boolean isExpanedEmptyElements = EXPANDABLE_HEAD_ELEMENT_TAG_NAME_SET.contains(tagName);
boolean isPreformattedTextContent = PREFORMATTED_HEAD_ELEMENT_TAG_NAME_SET.contains(tagName);
return toString(headElement, isExpanedEmptyElements, isPreformattedTextContent, true);
}
public static String toString(final HeadElement headElement, boolean isExpanedEmptyElements, boolean isPreformattedTextContent, boolean isPreformattedTextContentInCDATA)
{
StringWriter writer = new StringWriter(80);
try
{
writeHeadElement(writer, headElement, isExpanedEmptyElements, isPreformattedTextContent, isPreformattedTextContentInCDATA);
}
catch (IOException e)
{
log.error("IOException during writing to string writer for head element. {}", e.toString());
}
return writer.toString();
}
public static void writeHeadElement(final Writer writer, final HeadElement headElement, boolean isExpandEmptyElements, boolean isPreformattedTextContent, boolean isPreformattedTextContentInCDATA) throws IOException
{
String tagName = headElement.getTagName();
writer.write('<');
writer.write(tagName);
for (Map.Entry entry : headElement.getAttributeMap().entrySet())
{
writer.write(' ');
writer.write(entry.getKey());
writer.write("=\"");
writer.write(encode(entry.getValue()));
writer.write("\"");
}
if (!headElement.hasChildHeadElements())
{
String textContent = headElement.getTextContent();
if (!isExpandEmptyElements && (textContent == null || "".equals(textContent)))
{
writer.write("/>");
}
else
{
writer.write('>');
if (textContent != null)
{
if (isPreformattedTextContent)
{
if (isPreformattedTextContentInCDATA)
{
writer.write("");
}
else
{
writer.write(textContent);
}
}
else
{
writer.write(encode(textContent));
}
}
writer.write("');
}
}
else
{
writer.write(">\n");
for (HeadElement childHeadElement : headElement.getChildHeadElements())
{
writeHeadElement(writer, childHeadElement, isPreformattedTextContent, isExpandEmptyElements, isPreformattedTextContentInCDATA);
writer.write('\n');
}
writer.write("');
}
}
/**
* Escape <, > & ', " as their entities and
* drop characters that are illegal in XML documents.
* @param value the string to encode.
* @return the encoded string.
*/
public static String encode(String value) {
StringBuffer sb = new StringBuffer();
int len = value.length();
for (int i = 0; i < len; i++) {
char c = value.charAt(i);
switch (c) {
case '<':
sb.append("<");
break;
case '>':
sb.append(">");
break;
case '\'':
sb.append("'");
break;
case '\"':
sb.append(""");
break;
case '&':
int nextSemi = value.indexOf(";", i);
if (nextSemi < 0
|| !isReference(value.substring(i, nextSemi + 1))) {
sb.append("&");
} else {
sb.append('&');
}
break;
default:
if (isLegalCharacter(c)) {
sb.append(c);
}
break;
}
}
return sb.substring(0);
}
/**
* Is the given argument a character or entity reference?
* @param ent the value to be checked.
* @return true if it is an entity.
*/
private static boolean isReference(String ent) {
if (!(ent.charAt(0) == '&') || !ent.endsWith(";")) {
return false;
}
if (ent.charAt(1) == '#') {
if (ent.charAt(2) == 'x') {
try {
// CheckStyle:MagicNumber OFF
Integer.parseInt(ent.substring(3, ent.length() - 1), HEX);
// CheckStyle:MagicNumber ON
return true;
} catch (NumberFormatException nfe) {
return false;
}
} else {
try {
Integer.parseInt(ent.substring(2, ent.length() - 1));
return true;
} catch (NumberFormatException nfe) {
return false;
}
}
}
String name = ent.substring(1, ent.length() - 1);
for (int i = 0; i < KNOWN_ENTITIES.length; i++) {
if (name.equals(KNOWN_ENTITIES[i])) {
return true;
}
}
return false;
}
/**
* Is the given character allowed inside an XML document?
*
* See XML 1.0 2.2
* http://www.w3.org/TR/1998/REC-xml-19980210#charsets.
* @param c the character to test.
* @return true if the character is allowed.
*/
private static boolean isLegalCharacter(char c) {
// CheckStyle:MagicNumber OFF
if (c == 0x9 || c == 0xA || c == 0xD) {
return true;
} else if (c < 0x20) {
return false;
} else if (c <= 0xD7FF) {
return true;
} else if (c < 0xE000) {
return false;
} else if (c <= 0xFFFD) {
return true;
}
// CheckStyle:MagicNumber ON
return false;
}
}