org.glassfish.hk2.utilities.ClasspathDescriptorFileFinder Maven / Gradle / Ivy
/*
* Copyright (c) 2013, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package org.glassfish.hk2.utilities;
import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.List;
import org.glassfish.hk2.api.DescriptorFileFinder;
import org.glassfish.hk2.api.DescriptorFileFinderInformation;
import org.glassfish.hk2.utilities.reflection.Logger;
/**
* This is an implementation of {@link DescriptorFileFinder} that
* uses a particular classloader in order to find descriptor files.
* @author jwells
*
*/
public class ClasspathDescriptorFileFinder implements DescriptorFileFinder, DescriptorFileFinderInformation {
private final static String DEBUG_DESCRIPTOR_FINDER_PROPERTY = "org.jvnet.hk2.properties.debug.descriptor.file.finder";
private final static boolean DEBUG_DESCRIPTOR_FINDER = AccessController.doPrivileged(new PrivilegedAction() {
@Override
public Boolean run() {
return Boolean.parseBoolean(System.getProperty(DEBUG_DESCRIPTOR_FINDER_PROPERTY, "false"));
}
});
private final static String DEFAULT_NAME = "default";
private final ClassLoader classLoader;
private final String names[];
private final ArrayList identifiers = new ArrayList();
/**
* If this constructor is used then HK2 descriptor files will be found
* by looking in the classpath of the process. The classloader used
* will be the classloader for this class itself. The names of
* the files found will be META-INF/hk2-locator/default.
*
* This is most commonly used when using HK2 from a stand-alone client in
* which all the JAR files are on a single classpath
*/
public ClasspathDescriptorFileFinder() {
this(ClasspathDescriptorFileFinder.class.getClassLoader(), DEFAULT_NAME);
}
/**
* This constructor can be used to select the particular classloader
* to search for HK2 descriptor files. The names of the the files
* found in this classloader will be META-INF/hk2-locator/default.
*
* This is commonly used in more complex classloading scenarios where
* the HK2 descriptor files are not necessarily on the system classpath.
*
* @param cl May not be null and must be the classloader to use when
* searching for HK2 descriptor files
*/
public ClasspathDescriptorFileFinder (ClassLoader cl) {
this(cl, DEFAULT_NAME);
}
/**
* This constructor can be used to select the particular classloader
* to search for HK2 descriptor files. The names of the the files
* found in this classloader will be META-INF/hk2-locator/name.
*
* @param cl May not be null and must be the classloader to use when
* searching for HK2 descriptor files
* @param names May not be null and must be the name of the files to
* search for in the META-INF/hk2-locator directory
*/
public ClasspathDescriptorFileFinder (ClassLoader cl, String... names) {
this.classLoader = cl;
this.names = names;
}
/**
* Simple implementation of the findDescriptorFiles which does a
* simple getResources on the classloader in order to find the
* hk2 descriptor files
*/
@Override
public List findDescriptorFiles() throws IOException {
identifiers.clear();
ArrayList returnList = new ArrayList();
for (String name : names) {
Enumeration e = classLoader.getResources(RESOURCE_BASE+name);
for (; e.hasMoreElements();) {
URL url = e.nextElement();
if (DEBUG_DESCRIPTOR_FINDER) {
Logger.getLogger().debug("Adding in URL to set being parsed: " + url + " from " + RESOURCE_BASE+name);
}
try {
identifiers.add(url.toURI().toString());
}
catch (URISyntaxException e1) {
throw new IOException(e1);
}
InputStream inputStream;
try {
inputStream = url.openStream();
}
catch (IOException ioe) {
if (DEBUG_DESCRIPTOR_FINDER) {
Logger.getLogger().debug("IOException for url " + url, ioe);
}
throw ioe;
}
catch (Throwable th) {
if (DEBUG_DESCRIPTOR_FINDER) {
Logger.getLogger().debug("Unexpected exception for url " + url, th);
}
throw new IOException(th);
}
if (DEBUG_DESCRIPTOR_FINDER) {
Logger.getLogger().debug("Input stream for: " + url + " from " + RESOURCE_BASE+name + " has succesfully been opened");
}
returnList.add(inputStream);
}
}
return returnList;
}
/* (non-Javadoc)
* @see org.glassfish.hk2.api.DescriptorFileFinderInformation#getDescriptorFileInformation()
*/
@Override
public List getDescriptorFileInformation() {
return identifiers;
}
public String toString() {
return "ClasspathDescriptorFileFinder(" + classLoader + "," + Arrays.toString(names) + "," + System.identityHashCode(this) + ")";
}
}