Return a context-relative path, beginning with a "/", that represents the canonical version of the specified path after ".." and "." elements are resolved out.
/*
* 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.
*/
/**
*
*
* @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
* @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
* @version $Id: StringUtils.java 685685 2008-08-13 21:43:27Z nbubna $
*/
public class Main {
/**
* Return a context-relative path, beginning with a "/", that represents the
* canonical version of the specified path after ".." and "." elements are
* resolved out. If the specified path attempts to go outside the boundaries
* of the current context (i.e. too many ".." path elements are present),
* return <code>null</code> instead.
*
* @param path
* Path to be normalized
* @return String normalized path
*/
public static final String normalizePath(String path) {
// Normalize the slashes and add leading slash if necessary
String normalized = path;
if (normalized.indexOf('\\') >= 0) {
normalized = normalized.replace('\\', '/');
}
if (!normalized.startsWith("/")) {
normalized = "/" + normalized;
}
// Resolve occurrences of "//" in the normalized path
while (true) {
int index = normalized.indexOf("//");
if (index < 0)
break;
normalized = normalized.substring(0, index) + normalized.substring(index + 1);
}
// Resolve occurrences of "%20" in the normalized path
while (true) {
int index = normalized.indexOf("%20");
if (index < 0)
break;
normalized = normalized.substring(0, index) + " " + normalized.substring(index + 3);
}
// Resolve occurrences of "/./" in the normalized path
while (true) {
int index = normalized.indexOf("/./");
if (index < 0)
break;
normalized = normalized.substring(0, index) + normalized.substring(index + 2);
}
// Resolve occurrences of "/../" in the normalized path
while (true) {
int index = normalized.indexOf("/../");
if (index < 0)
break;
if (index == 0)
return (null); // Trying to go outside our context
int index2 = normalized.lastIndexOf('/', index - 1);
normalized = normalized.substring(0, index2) + normalized.substring(index + 3);
}
// Return the normalized path that we have completed
return (normalized);
}
}
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