edu.jhu.hlt.concrete.streams.NamedPipeCommunicationConsumer.java Source code

Introduction

Here is the source code for edu.jhu.hlt.concrete.streams.NamedPipeCommunicationConsumer.java

Source

/*
 * Copyright 2012-2016 Johns Hopkins University HLTCOE. All rights reserved.
 * See LICENSE in the project root directory.
 */
package edu.jhu.hlt.concrete.streams;

import java.io.IOException;

import org.apache.thrift.TException;
import org.apache.thrift.protocol.TCompactProtocol;
import org.apache.thrift.transport.TTransportException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import edu.jhu.hlt.concrete.Communication;
import edu.jhu.hlt.concrete.util.ConcreteException;

/**
 * Consume concrete {@link Communication}s from a named pipe.
 */
public class NamedPipeCommunicationConsumer {

    private static final Logger LOGGER = LoggerFactory.getLogger(NamedPipeCommunicationConsumer.class);

    private final TSimpleFileTransport tft;
    private final TCompactProtocol tcp;

    /**
     * @param pathStr a path to a named pipe with {@link Communication}s
     * @throws IOException
     */
    public NamedPipeCommunicationConsumer(final String pathStr) throws IOException {
        try {
            this.tft = new TSimpleFileTransport(pathStr);
            this.tft.open();
            this.tcp = new TCompactProtocol(tft);
        } catch (TTransportException e) {
            throw new IOException(e);
        }
    }

    /**
     *
     * @return true if there are {@link Communication}s left in the pipe or it is
     *         being written to
     */
    public boolean isOpen() {
        return this.tft.peek();
    }

    /**
     *
     * @return the next {@link Communication} from the pipe
     * @throws ConcreteException
     *           if there is an error with the serialization or transport of the
     *           communication
     */
    public Communication next() throws ConcreteException {
        Communication c = new Communication();
        try {
            c.read(this.tcp);
            return c;
        } catch (TException e) {
            throw new ConcreteException(e);
        }
    }

    /**
     * @param args
     * @throws IOException
     * @throws ConcreteException
     */
    public static void main(String[] args) throws IOException, ConcreteException {
        String filePathStr = args[0];
        NamedPipeCommunicationConsumer con = new NamedPipeCommunicationConsumer(filePathStr);
        LOGGER.info("Is it open? {}", con.isOpen());
        while (con.isOpen()) {
            LOGGER.info("Got ID: {}", con.next().getId());
        }
    }
}