/**
* 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.hadoop.fs;
import java.net.*;
import java.io.*;
import org.apache.hadoop.conf.Configuration;
/** Names a file or directory in a {@link FileSystem}.
* Path strings use slash as the directory separator. A path string is
* absolute if it begins with a slash.
*/
public class Path implements Comparable {
/** The directory separator, a slash. */
public static final String SEPARATOR = "/";
public static final char SEPARATOR_CHAR = '/';
public static final String CUR_DIR = ".";
static final boolean WINDOWS
= System.getProperty("os.name").startsWith("Windows");
private URI uri; // a hierarchical uri
/** Resolve a child path against a parent path. */
public Path(String parent, String child) {
this(new Path(parent), new Path(child));
}
/** Resolve a child path against a parent path. */
public Path(Path parent, String child) {
this(parent, new Path(child));
}
/** Resolve a child path against a parent path. */
public Path(String parent, Path child) {
this(new Path(parent), child);
}
/** Resolve a child path against a parent path. */
public Path(Path parent, Path child) {
// Add a slash to parent's path so resolution is compatible with URI's
URI parentUri = parent.uri;
String parentPath = parentUri.getPath();
if (!(parentPath.equals("/") || parentPath.equals("")))
try {
parentUri = new URI(parentUri.getScheme(), parentUri.getAuthority(),
parentUri.getPath()+"/", null, parentUri.getFragment());
} catch (URISyntaxException e) {
throw new IllegalArgumentException(e);
}
URI resolved = parentUri.resolve(child.uri);
initialize(resolved.getScheme(), resolved.getAuthority(),
normalizePath(resolved.getPath()), resolved.getFragment());
}
private void checkPathArg( String path ) {
// disallow construction of a Path from an empty string
if ( path == null ) {
throw new IllegalArgumentException(
"Can not create a Path from a null string");
}
if( path.length() == 0 ) {
throw new IllegalArgumentException(
"Can not create a Path from an empty string");
}
}
/** Construct a path from a String. Path strings are URIs, but with
* unescaped elements and some additional normalization. */
public Path(String pathString) {
checkPathArg( pathString );
// We can't use 'new URI(String)' directly, since it assumes things are
// escaped, which we don't require of Paths.
// add a slash in front of paths with Windows drive letters
if (hasWindowsDrive(pathString, false))
pathString = "/"+pathString;
// parse uri components
String scheme = null;
String authority = null;
int start = 0;
// parse uri scheme, if any
int colon = pathString.indexOf(':');
int slash = pathString.indexOf('/');
if ((colon != -1) &&
((slash == -1) || (colon < slash))) { // has a scheme
scheme = pathString.substring(0, colon);
start = colon+1;
}
// parse uri authority, if any
if (pathString.startsWith("//", start) &&
(pathString.length()-start > 2)) { // has authority
int nextSlash = pathString.indexOf('/', start+2);
int authEnd = nextSlash > 0 ? nextSlash : pathString.length();
authority = pathString.substring(start+2, authEnd);
start = authEnd;
}
// uri path is the rest of the string -- query & fragment not supported
String path = pathString.substring(start, pathString.length());
initialize(scheme, authority, path, null);
}
/** Construct a Path from components. */
public Path(String scheme, String authority, String path) {
checkPathArg( path );
initialize(scheme, authority, path, null);
}
/**
* Construct a path from a URI
*/
public Path(URI aUri) {
uri = aUri;
}
private void initialize(String scheme, String authority, String path,
String fragment) {
try {
this.uri = new URI(scheme, authority, normalizePath(path), null, fragment)
.normalize();
} catch (URISyntaxException e) {
throw new IllegalArgumentException(e);
}
}
private String normalizePath(String path) {
// remove double slashes & backslashes
if (path.indexOf("//") != -1) {
path = path.replace("//", "/");
}
if (Path.WINDOWS && path.indexOf("\\") != -1) {
path = path.replace("\\", "/");
}
// trim trailing slash from non-root path (ignoring windows drive)
int minLength = hasWindowsDrive(path, true) ? 4 : 1;
if (path.length() > minLength && path.endsWith("/")) {
path = path.substring(0, path.length()-1);
}
return path;
}
private boolean hasWindowsDrive(String path, boolean slashed) {
if (!WINDOWS) return false;
int start = slashed ? 1 : 0;
return
path.length() >= start+2 &&
(slashed ? path.charAt(0) == '/' : true) &&
path.charAt(start+1) == ':' &&
((path.charAt(start) >= 'A' && path.charAt(start) <= 'Z') ||
(path.charAt(start) >= 'a' && path.charAt(start) <= 'z'));
}
/** Convert this to a URI. */
public URI toUri() { return uri; }
/** Return the FileSystem that owns this Path. */
public FileSystem getFileSystem(Configuration conf) throws IOException {
return FileSystem.get(this.toUri(), conf);
}
/** True if the directory of this path is absolute. */
public boolean isAbsolute() {
int start = hasWindowsDrive(uri.getPath(), true) ? 3 : 0;
return uri.getPath().startsWith(SEPARATOR, start);
}
/** Returns the final component of this path.*/
public String getName() {
String path = uri.getPath();
int slash = path.lastIndexOf(SEPARATOR);
return path.substring(slash+1);
}
/** Returns the parent of a path or null if at root. */
public Path getParent() {
String path = uri.getPath();
int lastSlash = path.lastIndexOf('/');
int start = hasWindowsDrive(path, true) ? 3 : 0;
if ((path.length() == start) || // empty path
(lastSlash == start && path.length() == start+1)) { // at root
return null;
}
String parent;
if (lastSlash==-1) {
parent = CUR_DIR;
} else {
int end = hasWindowsDrive(path, true) ? 3 : 0;
parent = path.substring(0, lastSlash==end?end+1:lastSlash);
}
return new Path(uri.getScheme(), uri.getAuthority(), parent);
}
/** Adds a suffix to the final name in the path.*/
public Path suffix(String suffix) {
return new Path(getParent(), getName()+suffix);
}
public String toString() {
// we can't use uri.toString(), which escapes everything, because we want
// illegal characters unescaped in the string, for glob processing, etc.
StringBuffer buffer = new StringBuffer();
if (uri.getScheme() != null) {
buffer.append(uri.getScheme());
buffer.append(":");
}
if (uri.getAuthority() != null) {
buffer.append("//");
buffer.append(uri.getAuthority());
}
if (uri.getPath() != null) {
String path = uri.getPath();
if (path.indexOf('/')==0 &&
hasWindowsDrive(path, true) && // has windows drive
uri.getScheme() == null && // but no scheme
uri.getAuthority() == null) // or authority
path = path.substring(1); // remove slash before drive
buffer.append(path);
}
if (uri.getFragment() != null) {
buffer.append("#");
buffer.append(uri.getFragment());
}
return buffer.toString();
}
public boolean equals(Object o) {
if (!(o instanceof Path)) {
return false;
}
Path that = (Path)o;
return this.uri.equals(that.uri);
}
public int hashCode() {
return uri.hashCode();
}
public int compareTo(Object o) {
Path that = (Path)o;
return this.uri.compareTo(that.uri);
}
/** Return the number of elements in this path. */
public int depth() {
String path = uri.getPath();
int depth = 0;
int slash = path.length()==1 && path.charAt(0)=='/' ? -1 : 0;
while (slash != -1) {
depth++;
slash = path.indexOf(SEPARATOR, slash+1);
}
return depth;
}
/** Returns a qualified path object. */
public Path makeQualified(FileSystem fs) {
Path path = this;
if (!isAbsolute()) {
path = new Path(fs.getWorkingDirectory(), this);
}
URI pathUri = path.toUri();
URI fsUri = fs.getUri();
String scheme = pathUri.getScheme();
String authority = pathUri.getAuthority();
String fragment = pathUri.getFragment();
if (scheme != null &&
(authority != null || fsUri.getAuthority() == null))
return path;
if (scheme == null) {
scheme = fsUri.getScheme();
}
if (authority == null) {
authority = fsUri.getAuthority();
if (authority == null) {
authority = "";
}
}
URI newUri = null;
try {
newUri = new URI(scheme, authority ,
normalizePath(pathUri.getPath()), null, fragment);
} catch (URISyntaxException e) {
throw new IllegalArgumentException(e);
}
return new Path(newUri);
}
/** Returns a qualified path object. */
public Path makeQualified(URI defaultUri, Path workingDir ) {
Path path = this;
if (!isAbsolute()) {
path = new Path(workingDir, this);
}
URI pathUri = path.toUri();
String scheme = pathUri.getScheme();
String authority = pathUri.getAuthority();
String fragment = pathUri.getFragment();
if (scheme != null &&
(authority != null || defaultUri.getAuthority() == null))
return path;
if (scheme == null) {
scheme = defaultUri.getScheme();
}
if (authority == null) {
authority = defaultUri.getAuthority();
if (authority == null) {
authority = "";
}
}
URI newUri = null;
try {
newUri = new URI(scheme, authority ,
normalizePath(pathUri.getPath()), null, fragment);
} catch (URISyntaxException e) {
throw new IllegalArgumentException(e);
}
return new Path(newUri);
}
}