container/openejb-core/src/main/java/org/apache/openejb/util/DaemonThreadFactory.java

/*
 * 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.openejb.util;

import org.apache.openejb.core.ParentClassLoaderFinder;

import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicInteger;

import static org.apache.openejb.util.Join.join;

/**
 * @version $Rev$ $Date$
 */
public class DaemonThreadFactory implements ThreadFactory {

    private final String name;
    private final ThreadGroup group;
    private final AtomicInteger ids = new AtomicInteger(0);

    public DaemonThreadFactory(final Object... name) {
        this.name = join(" ", name).trim();
        final SecurityManager securityManager = System.getSecurityManager();
        if (securityManager != null) {
            group = securityManager.getThreadGroup();
        } else {
            group = Thread.currentThread().getThreadGroup();
        }
    }

    public DaemonThreadFactory(final Class... clazz) {
        this(asStrings(clazz));
    }

    private static Object[] asStrings(final Class[] clazz) {
        final String[] strings = new String[clazz.length];
        int i = 0;
        for (final Class c : clazz) {
            strings[i++] = c.getSimpleName();
        }
        return strings;
    }

    @Override
    public Thread newThread(final Runnable runnable) {
        final ClassLoader loader = Thread.currentThread().getContextClassLoader();
        Thread.currentThread().setContextClassLoader(ParentClassLoaderFinder.Helper.get());
        try {
            final Thread thread = new Thread(group, runnable, name + " - " + ids.incrementAndGet());
            if (!thread.isDaemon()) {
                thread.setDaemon(true);
            }
            if (thread.getPriority() != Thread.NORM_PRIORITY) {
                thread.setPriority(Thread.NORM_PRIORITY);
            }
            return thread;
        } finally {
            Thread.currentThread().setContextClassLoader(loader);
        }
    }
}