ProcExecutorWriteEventListener.java

/*
 * Copyright (c) 2013 GigaSpaces Technologies Ltd. All rights reserved
 *
 * Licensed 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 beans;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import play.cache.Cache;
import server.WriteEventListener;

import java.util.concurrent.Callable;

/**
 * 
 * A process executer output stream event listener.
 * This event listener writes all output from the process into the Play Cash. 
 * 
 * @author adaml
 *
 */
public class ProcExecutorWriteEventListener implements WriteEventListener {

	private String serverNodeId;

    private static Logger logger = LoggerFactory.getLogger( ProcExecutorWriteEventListener.class );

    private static Logger cliOutput = LoggerFactory.getLogger( "cliOutput");
	
	private StringBuilder sb = null;
	
	private String keyFormat = "output-%s";

	public ProcExecutorWriteEventListener(String serverNodeId) {
		this.serverNodeId = serverNodeId;
	}
	
	public ProcExecutorWriteEventListener() {
		
	}

    private String getKey(){
        return String.format( keyFormat, serverNodeId );
    }

    @Override
    public void init()
    {
        sb = new StringBuilder();
        logger.info( "initializing" );
        try {
            sb = Cache.getOrElse( getKey(), new Callable<StringBuilder>() {
                @Override
                public StringBuilder call() throws Exception
                {
                    logger.info( "initializing a new string builder" );
                    return new StringBuilder();
                }
            }, 0 );
        } catch ( Exception e ) {
            logger.error( "unable to getOrElse string builder", e );
            sb = new StringBuilder();
            Cache.set( getKey(), sb );
        }
    }

    @Override
    public void writeEvent(String s, int i) {
        sb.append( s ).append("\n");
        MDC.put( "servernodeid", serverNodeId );
        cliOutput.info(s);

    }

    public void setKeyFormat( String keyFormat ){
		this.keyFormat = keyFormat;
	}

	@Override
	public void setKey(String serverNodeId) {
		this.serverNodeId = serverNodeId;
	}

}