/*******************************************************************************
* Copyright (c) 2006, 2009 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.core.runtime;
import java.io.*;
import java.net.URL;
import java.util.Map;
import org.eclipse.core.internal.runtime.Activator;
import org.eclipse.core.internal.runtime.FindSupport;
import org.eclipse.osgi.service.urlconversion.URLConverter;
import org.osgi.framework.Bundle;
/**
* This class contains a collection of helper methods for finding files in bundles.
* This class can only be used if the OSGi plugin is available.
*
* @since org.eclipse.equinox.common 3.2
* @noinstantiate This class is not intended to be instantiated by clients.
*/
public final class FileLocator {
private FileLocator() {
// prevent instantiation
}
/**
* Returns a URL for the given path in the given bundle. Returns <code>null</code> if the URL
* could not be computed or created.
* <p>
* This method looks for the path in the given bundle and any attached fragments.
* <code>null</code> is returned if no such entry is found. Note that
* there is no specific order to the fragments.
* </p><p>
* The following variables may also be used as entries in the provided path:
* <ul>
* <li>$nl$ - for language specific information</li>
* <li>$os$ - for operating system specific information</li>
* <li>$ws$ - for windowing system specific information</li>
* </ul>
* </p><p>
* A path of "$nl$/about.properties" in an environment with a default
* locale of en_CA will return a URL corresponding to the first location
* about.properties is found according to the following order:
* <pre>
* plugin root/nl/en/CA/about.properties
* fragment1 root/nl/en/CA/about.properties
* fragment2 root/nl/en/CA/about.properties
* ...
* plugin root/nl/en/about.properties
* fragment1 root/nl/en/about.properties
* fragment2 root/nl/en/about.properties
* ...
* plugin root/about.properties
* fragment1 root/about.properties
* fragment2 root/about.properties
* ...
* </pre>
* </p><p>
* The current environment variable values can be overridden using
* the override map argument or <code>null</code> can be specified
* if this is not desired.
* </p>
*
* @param bundle the bundle in which to search
* @param path file path relative to plug-in installation location
* @param override map of override substitution arguments to be used for
* any $arg$ path elements. The map keys correspond to the substitution
* arguments (eg. "$nl$" or "$os$"). The resulting
* values must be of type java.lang.String. If the map is <code>null</code>,
* or does not contain the required substitution argument, the default
* is used.
* @return a URL for the given path or <code>null</code>. The actual form
* of the returned URL is not specified.
*/
public static URL find(Bundle bundle, IPath path, Map override) {
return FindSupport.find(bundle, path, override);
}
/**
* This method is the same as {@link #find(Bundle, IPath, Map)} except multiple entries
* can be returned if more than one entry matches the path in the host and
* any of its fragments.
*
* @param bundle the bundle in which to search
* @param path file path relative to plug-in installation location
* @param override map of override substitution arguments to be used for
* any $arg$ path elements. The map keys correspond to the substitution
* arguments (eg. "$nl$" or "$os$"). The resulting
* values must be of type java.lang.String. If the map is <code>null</code>,
* or does not contain the required substitution argument, the default
* is used.
* @return an array of entries which match the given path. An empty
* array is returned if no matches are found.
*
* @since org.eclipse.equinox.common 3.3
*/
public static URL[] findEntries(Bundle bundle, IPath path, Map override) {
return FindSupport.findEntries(bundle, path, override);
}
/**
* Returns the URL of a resource inside a bundle corresponding to the given URL.
* Returns <code>null</code> if the URL could not be computed or created.
* <p>
* This method looks for a bundle resource described by the given input URL,
* and returns the URL of the first resource found in the bundle or any attached
* fragments. <code>null</code> is returned if no such entry is found. Note that
* there is no specific order to the fragments.
* </p><p>
* The following variables may also be used as segments in the path of the provided URL:
* <ul>
* <li>$nl$ - for language specific information</li>
* <li>$os$ - for operating system specific information</li>
* <li>$ws$ - for windowing system specific information</li>
* </ul>
* </p><p>
* For example, a URL of "platform:/plugin/org.eclipse.core.runtime/$nl$/about.properties" in an
* environment with a default locale of en_CA will return a URL corresponding to
* the first location about.properties is found according to the following order:
* <pre>
* plugin root/nl/en/CA/about.properties
* fragment1 root/nl/en/CA/about.properties
* fragment2 root/nl/en/CA/about.properties
* ...
* plugin root/nl/en/about.properties
* fragment1 root/nl/en/about.properties
* fragment2 root/nl/en/about.properties
* ...
* plugin root/about.properties
* fragment1 root/about.properties
* fragment2 root/about.properties
* ...
* </pre>
* </p>
*
* @param url The location of a bundle entry that potentially includes the above
* environment variables
* @return The URL of the bundle entry matching the input URL, or <code>null</code>
* if no matching entry could be found. The actual form of the returned URL is not specified.
* @since org.eclipse.equinox.common 3.5
*/
public static URL find(URL url) {
return FindSupport.find(url);
}
/**
* This is a convenience method, fully equivalent to {@link #findEntries(Bundle, IPath, Map)},
* with a value of <code>null</code> for the map argument.
*
* @param bundle the bundle in which to search
* @param path file path relative to plug-in installation location
* @return an array of entries which match the given path. An empty
* array is returned if no matches are found.
*
* @since org.eclipse.equinox.common 3.3
*/
public static URL[] findEntries(Bundle bundle, IPath path) {
return FindSupport.findEntries(bundle, path);
}
/**
* Returns an input stream for the specified file. The file path
* must be specified relative to this plug-in's installation location.
* Optionally, the path specified may contain $arg$ path elements that can
* be used as substitution arguments. If this option is used then the $arg$
* path elements are processed in the same way as {@link #find(Bundle, IPath, Map)}.
* <p>
* The caller must close the returned stream when done.
* </p>
*
* @param bundle the bundle in which to search
* @param file path relative to plug-in installation location
* @param substituteArgs <code>true</code> to process substitution arguments,
* and <code>false</code> for the file exactly as specified without processing any
* substitution arguments.
* @return an input stream
* @exception IOException if the given path cannot be found in this plug-in
*/
public static InputStream openStream(Bundle bundle, IPath file, boolean substituteArgs) throws IOException {
return FindSupport.openStream(bundle, file, substituteArgs);
}
/**
* Converts a URL that uses a user-defined protocol into a URL that uses the file
* protocol. The contents of the URL may be extracted into a cache on the file-system
* in order to get a file URL.
* <p>
* If the protocol for the given URL is not recognized by this converter, the original
* URL is returned as-is.
* </p>
* @param url the original URL
* @return the converted file URL or the original URL passed in if it is
* not recognized by this converter
* @throws IOException if an error occurs during the conversion
*/
public static URL toFileURL(URL url) throws IOException {
URLConverter converter = Activator.getURLConverter(url);
return converter == null ? url : converter.toFileURL(url);
}
/**
* Converts a URL that uses a client-defined protocol into a URL that uses a
* protocol which is native to the Java class library (file, jar, http, etc).
* <p>
* Note however that users of this API should not assume too much about the
* results of this method. While it may consistently return a file: URL in certain
* installation configurations, others may result in jar: or http: URLs.
* </p>
* <p>
* If the protocol is not recognized by this converter, then the original URL is
* returned as-is.
* </p>
* @param url the original URL
* @return the resolved URL or the original if the protocol is unknown to this converter
* @exception IOException if unable to resolve URL
* @throws IOException if an error occurs during the resolution
*/
public static URL resolve(URL url) throws IOException {
URLConverter converter = Activator.getURLConverter(url);
return converter == null ? url : converter.resolve(url);
}
/**
* Returns a file for the contents of the specified bundle. Depending
* on how the bundle is installed the returned file may be a directory or a jar file
* containing the bundle content.
*
* @param bundle the bundle
* @return a file with the contents of the bundle
* @throws IOException if an error occurs during the resolution
*
* @since org.eclipse.equinox.common 3.4
*/
public static File getBundleFile(Bundle bundle) throws IOException {
URL rootEntry = bundle.getEntry("/"); //$NON-NLS-1$
rootEntry = resolve(rootEntry);
if ("file".equals(rootEntry.getProtocol())) //$NON-NLS-1$
return new File(rootEntry.getPath());
if ("jar".equals(rootEntry.getProtocol())) { //$NON-NLS-1$
String path = rootEntry.getPath();
if (path.startsWith("file:")) {
// strip off the file: and the !/
path = path.substring(5, path.length() - 2);
return new File(path);
}
}
throw new IOException("Unknown protocol"); //$NON-NLS-1$
}
}