org.apache.slider.server.services.utility.LaunchedWorkflowCompositeService.java Source code

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Here is the source code for org.apache.slider.server.services.utility.LaunchedWorkflowCompositeService.java

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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.slider.server.services.utility;

import com.google.common.base.Preconditions;
import org.apache.commons.lang.StringUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.service.Service;
import org.apache.slider.core.main.LauncherExitCodes;
import org.apache.slider.core.main.RunService;
import org.apache.slider.server.services.workflow.WorkflowCompositeService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This is a workflow compositoe service which can be launched from the CLI
 * ... catches the arguments and implements a stub runService operation.
 */
public class LaunchedWorkflowCompositeService extends WorkflowCompositeService implements RunService {
    private static final Logger log = LoggerFactory.getLogger(LaunchedWorkflowCompositeService.class);
    private String[] argv;

    public LaunchedWorkflowCompositeService(String name) {
        super(name);
    }

    public LaunchedWorkflowCompositeService(String name, Service... children) {
        super(name, children);
    }

    /**
     * Implementation of set-ness, groovy definition of true/false for a string
     * @param s
     * @return
     */
    protected static boolean isUnset(String s) {
        return StringUtils.isEmpty(s);
    }

    protected static boolean isSet(String s) {
        return StringUtils.isNotEmpty(s);
    }

    protected String[] getArgv() {
        return argv;
    }

    /**
     * Pre-init argument binding
     * @param config the initial configuration build up by the
     * service launcher.
     * @param args argument list list of arguments passed to the command line
     * after any launcher-specific commands have been stripped.
     * @return the configuration
     * @throws Exception
     */
    @Override
    public Configuration bindArgs(Configuration config, String... args) throws Exception {
        this.argv = args;
        if (log.isDebugEnabled()) {
            log.debug("Binding {} Arguments:", args.length);

            StringBuilder builder = new StringBuilder();
            for (String arg : args) {
                builder.append('"').append(arg).append("\" ");
            }
            log.debug(builder.toString());
        }
        return config;
    }

    @Override
    public int runService() throws Throwable {
        return LauncherExitCodes.EXIT_SUCCESS;
    }

    @Override
    public synchronized void addService(Service service) {
        Preconditions.checkArgument(service != null, "null service argument");
        super.addService(service);
    }

    /**
     * Run a child service -initing and starting it if this
     * service has already passed those parts of its own lifecycle
     * @param service the service to start
     */
    protected boolean deployChildService(Service service) {
        service.init(getConfig());
        addService(service);
        if (isInState(STATE.STARTED)) {
            service.start();
            return true;
        }
        return false;
    }

}