org.datayoo.moql.util.PathUtils 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.
*/
package org.datayoo.moql.util;
import org.apache.commons.lang3.StringUtils;
import java.util.LinkedList;
import java.util.List;
/**
*
* @author Tang Tadin
*
*/
public abstract class PathUtils {
public static final String FOLDER_SEPARATOR = "/";
public static final String WINDOWS_FOLDER_SEPARATOR = "\\";
public static final String TOP_PATH = "..";
public static final String CURRENT_PATH = ".";
public static final char DOT_CHAR = '.';
public static final char FOLDER_SEPARATOR_CHAR = '/';
public static int lastIndexOfFolderSeparator(String path) {
int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);
if (separatorIndex == -1) {
return path.lastIndexOf(WINDOWS_FOLDER_SEPARATOR);
}
return separatorIndex;
}
/**
* Extract the filename from the given path, e.g. "mypath/myfile.txt" ->
* "myfile.txt".
*
* @param path the file path
* @return the extracted filename, or null if none
*/
public static String getFileName(String path) {
if (path == null) {
return null;
}
int separatorIndex = lastIndexOfFolderSeparator(path);
return (separatorIndex != -1 ? path.substring(separatorIndex + 1) : path);
}
/**
* Extract the path from the given path, e.g. "mypath/myfile.txt" ->
* "mypath/".
*
* @param path the file path
* @return the extracted file's path, or null if none
*/
public static String getFilePath(String path) {
if (path == null) {
return null;
}
int separatorIndex = lastIndexOfFolderSeparator(path);
return (separatorIndex != -1 ?
path.substring(0, separatorIndex + 1) :
path);
}
/**
* Extract the filename extension from the given path, e.g.
* "mypath/myfile.txt" -> "txt".
*
* @param path the file path
* @return the extracted filename extension, or null if none
*/
public static String getFileNameExtension(String path) {
if (path == null) {
return null;
}
int separatorIndex = path.lastIndexOf(DOT_CHAR);
return (separatorIndex != -1 ? path.substring(separatorIndex + 1) : null);
}
/**
* Join the given relative path to the given path, assuming standard Java
* folder separation (i.e. "/" separators);
*
* @param path the path to start from (usually a full file path)
* @param relativePath the relative path to apply
* @return the full file path that results from applying the relative path
*/
public static String joinPath(String path, String relativePath) {
int separatorIndex = lastIndexOfFolderSeparator(path);
if (separatorIndex != -1) {
String newPath = path.substring(0, separatorIndex);
if (!(relativePath.charAt(0) == FOLDER_SEPARATOR_CHAR)) {
newPath += FOLDER_SEPARATOR;
}
return newPath + relativePath;
} else {
return relativePath;
}
}
/**
* Normalize the path by removing the ".." and "." from path.
*
* The result is convenient for path comparison. For other uses, notice that
* Windows separators ("\") are replaced by simple slashes.
*
* @param path the original path
* @return the normalized path
*/
public static String toCanonicalPath(String path) {
if (path == null) {
return null;
}
String pathToUse = StringUtils
.replace(path, WINDOWS_FOLDER_SEPARATOR, FOLDER_SEPARATOR);
/* Strip prefix from path to analyze, to not treat it as part of the
first path element. This is necessary to correctly parse paths like
"file:root/../root/util/utils.xml", where the ".." should just
strip the first "root" directory while keeping the "file:" prefix.*/
int prefixIndex = pathToUse.indexOf(":");
String prefix = "";
if (prefixIndex != -1) {
prefix = pathToUse.substring(0, prefixIndex + 1);
pathToUse = pathToUse.substring(prefixIndex + 1);
}
if (pathToUse.charAt(0) == FOLDER_SEPARATOR_CHAR) {
if (pathToUse.charAt(1) == FOLDER_SEPARATOR_CHAR) {
prefix = new StringBuffer(prefix).append(FOLDER_SEPARATOR_CHAR).
append(FOLDER_SEPARATOR_CHAR).toString();
pathToUse = pathToUse.substring(2);
} else {
prefix = prefix + FOLDER_SEPARATOR;
pathToUse = pathToUse.substring(1);
}
}
String[] pathArray = StringUtils.split(pathToUse, FOLDER_SEPARATOR);
List pathElements = new LinkedList();
int tops = 0;
for (int i = pathArray.length - 1; i >= 0; i--) {
String element = pathArray[i];
if (CURRENT_PATH.equals(element)) {
// Points to current directory - drop it.
} else if (TOP_PATH.equals(element)) {
// Registering top path found.
tops++;
} else {
if (tops > 0) {
// Merging path element with element corresponding to top
// path.
tops--;
} else {
// Normal path element found.
pathElements.add(0, element);
}
}
}
// Remaining top paths need to be retained.
for (int i = 0; i < tops; i++) {
pathElements.add(0, TOP_PATH);
}
pathElements.add(0, prefix);
return StringUtils.join(pathElements, FOLDER_SEPARATOR);
}
/**
* Return whether the path is a relative path which start
* with "." or "..".
* @param path the given path
* @return the relative path
*/
public static boolean isRelativePath(String path) {
if (path.charAt(0) == DOT_CHAR)
return true;
return false;
}
}