/*
* 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.sling.commons.osgi.bundleversion;
import org.osgi.framework.Version;
/** Provides bundle version information, which can be
* extracted from bundle files or Bundle objects.
*/
public abstract class BundleVersionInfo<T> implements Comparable<BundleVersionInfo<?>> {
private static final int A_GREATER = 1;
private static final int B_GREATER = -1;
private static final int EQUAL = 0;
/** Marker used by Maven to identify snapshots */
public static final String SNAPSHOT_MARKER = "SNAPSHOT";
/** Name of the BND attribute that provides the bundle's last modified timestamp */
public static final String BND_LAST_MODIFIED = "Bnd-LastModified";
/** Value for {@link #getBundleLastModified} if corresponding header
* is not present
*/
public static final long BND_LAST_MODIFIED_MISSING = -1L;
/** Return the source of information: underlying File or Bundle */
public abstract T getSource();
/** True if the provided data is a valid bundle */
public abstract boolean isBundle();
/** Return the bundle symbolic name, null if not available */
public abstract String getBundleSymbolicName();
/** Return the bundle version, null if not available */
public abstract Version getVersion();
/** True if the bundle version indicates a snapshot */
public abstract boolean isSnapshot();
/** Return the bundle last modification time, based on the BND_LAST_MODIFIED
* manifest header, if available. This is *not* the Bundle.getLastModified()
* value, which refers to actions in the OSGi framework.
* @return BND_LAST_MODIFIED_MISSING if header not supplied */
public abstract long getBundleLastModified();
/** Compare based on bundle version info, and for snapshots
* based on {@link #getBundleLastModified}
*/
public int compareTo(BundleVersionInfo<?> other) {
// Handle null values
if(other == null) {
throw new IllegalArgumentException("b is null, cannot compare");
}
// Handle non-bundles: we don't want them!
if(!isBundle()) {
throw new IllegalArgumentException("Not a bundle, cannot compare: " + this);
}
if(!other.isBundle()) {
throw new IllegalArgumentException("Not a bundle, cannot compare:" + other);
}
// First compare symbolic names
int result = getBundleSymbolicName().compareTo(other.getBundleSymbolicName());
// Then compare versions
if(result == EQUAL) {
final Version va = getVersion();
final Version vb = other.getVersion();
if(va == null && vb == null) {
// result = EQUAL
} else if(vb == null) {
result = A_GREATER;
} else if(va == null) {
result = B_GREATER;
} else {
result = va.compareTo(vb);
}
}
// Then, if snapshots, compare modification times, more recent comes first
if(result == EQUAL && isSnapshot()) {
final long ma = getBundleLastModified();
final long mb = other.getBundleLastModified();
if(ma > mb) {
result = A_GREATER;
} else if(mb > ma) {
result = B_GREATER;
}
}
return result;
}
}