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/*
* 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.felix.systemready.impl;
import java.io.Closeable;
import org.osgi.framework.BundleContext;
import org.osgi.framework.Filter;
import org.osgi.framework.FrameworkUtil;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.util.tracker.ServiceTracker;
class Tracker implements Closeable {
private ServiceTracker,?> stracker;
public Tracker(BundleContext context, String nameOrFilter) {
String filterSt = nameOrFilter.startsWith("(") ? nameOrFilter : String.format("(objectClass=%s)", nameOrFilter);
Filter filter;
try {
filter = FrameworkUtil.createFilter(filterSt);
} catch (InvalidSyntaxException e) {
throw new IllegalArgumentException("Error creating filter for " + nameOrFilter);
}
this.stracker = new ServiceTracker<>(context, filter, null);
this.stracker.open();
}
public boolean present() {
return this.stracker.getTrackingCount() > 0;
}
@Override
public void close() {
stracker.close();
}
}