/*******************************************************************************
* Copyright (c) 2006 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.IOException;
import java.io.InputStream;
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 collection of helper methods aimed at finding files in bundles.
* This class can only be used if OSGi plugin is available.
* <p>
* The class is not intended to be subclassed or instantiated by clients.
* </p>
* @since org.eclipse.equinox.common 3.2
*/
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>
* find looks for this path in 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 arguments may also be used
* <pre>
* $nl$ - for language specific information
* $os$ - for operating system specific information
* $ws$ - for windowing system specific information
* </pre>
* </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 place
* 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);
}
/**
* Same as {@link #findEntries(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);
}
/**
* Same as {@link #findEntries(Bundle, IPath)} except multiple entries
* can be returned if more than one entry matches the path in the host
* any of its fragments.
*
* @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);
}
}