/*
* 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 com.todoroo.astrid.utility;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
/**
* <p>Escapes and unescapes <code>String</code>s for
* Java, Java Script, HTML, XML, and SQL.</p>
*
* @author Apache Jakarta Turbine
* @author Purple Technology
* @author <a href="mailto:alex@purpletech.com">Alexander Day Chaffee</a>
* @author Antony Riley
* @author Helge Tesgaard
* @author <a href="sean@boohai.com">Sean Brown</a>
* @author <a href="mailto:ggregory@seagullsw.com">Gary Gregory</a>
* @author Phil Steitz
* @author Pete Gieser
* @since 2.0
* @version $Id: StringEscapeUtils.java 2696 2007-06-20 13:24:53Z damencho $
*/
@SuppressWarnings({"nls"})
public class StringEscapeUtils {
/**
* <p><code>StringEscapeUtils</code> instances should NOT be constructed in
* standard programming.</p>
*
* <p>Instead, the class should be used as:
* <pre>StringEscapeUtils.escapeJava("foo");</pre></p>
*
* <p>This constructor is public to permit tools that require a JavaBean
* instance to operate.</p>
*/
public StringEscapeUtils() {
super();
}
//-----------------------------------------------------------------------
/**
* <p>Unescapes a string containing entity escapes to a string
* containing the actual Unicode characters corresponding to the
* escapes. Supports HTML 4.0 entities.</p>
*
* <p>For example, the string "<Français>"
* will become "<Français>"</p>
*
* <p>If an entity is unrecognized, it is left alone, and inserted
* verbatim into the result string. e.g. ">&zzzz;x" will
* become ">&zzzz;x".</p>
*
* @param str the <code>String</code> to unescape, may be null
* @return a new unescaped <code>String</code>, <code>null</code> if null string input
* @see #escapeHtml(Writer, String)
*/
public static String unescapeHtml(String str) {
if (str == null) {
return null;
}
try {
StringWriter writer = new StringWriter ((int)(str.length() * 1.5));
unescapeHtml(writer, str);
return writer.toString();
} catch (IOException e) {
//assert false;
//should be impossible
e.printStackTrace();
return null;
}
}
/**
* <p>Unescapes a string containing entity escapes to a string
* containing the actual Unicode characters corresponding to the
* escapes. Supports HTML 4.0 entities.</p>
*
* <p>For example, the string "<Français>"
* will become "<Français>"</p>
*
* <p>If an entity is unrecognized, it is left alone, and inserted
* verbatim into the result string. e.g. ">&zzzz;x" will
* become ">&zzzz;x".</p>
*
* @param writer the writer receiving the unescaped string, not null
* @param string the <code>String</code> to unescape, may be null
* @throws IllegalArgumentException if the writer is null
* @throws IOException if an IOException occurs
* @see #escapeHtml(String)
*/
public static void unescapeHtml(Writer writer, String string) throws IOException {
if (writer == null ) {
throw new IllegalArgumentException ("The Writer must not be null.");
}
if (string == null) {
return;
}
Entities.HTML40.unescape(writer, string);
}
}