edu.brandeis.ggen.GGenCommand.java Source code

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Here is the source code for edu.brandeis.ggen.GGenCommand.java

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// { begin copyright } 
// Copyright Ryan Marcus 2016
// 
// This file is part of poingnard.
// 
// poingnard is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// poingnard is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with poingnard.  If not, see <http://www.gnu.org/licenses/>.
// 
// { end copyright } 

package edu.brandeis.ggen;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;

import org.apache.commons.io.IOUtils;

class GGenCommand extends GraphGenerator {

    public static String GGEN_PATH = "ggen";

    private String args;
    private GraphGenerator input;

    public GGenCommand(String args) {
        this.args = args;
        this.input = null;
    }

    public GGenCommand(String args, GraphGenerator input) {
        this.args = args;

        // TODO in future versions, we could stream this with pipes
        this.input = input;
    }

    public String generateGraphviz() throws GGenException {
        ProcessBuilder pb = new ProcessBuilder();
        List<String> command = new LinkedList<>();
        command.add(GGEN_PATH);
        Arrays.stream(args.split(" ")).forEach(command::add);

        try {
            Process p = pb.command(command).start();

            if (this.input != null)
                p.getOutputStream().write(this.input.generateGraphviz().getBytes());
            p.getOutputStream().close();

            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            IOUtils.copy(p.getInputStream(), bos);
            return new String(bos.toByteArray());
        } catch (IOException e) {
            throw new GGenException(
                    "Could not launch the ggen command. Check that the GGenCommand.GGEN_PATH static variable is correctly set for your system. Message: "
                            + e.getMessage());
        }
    }
}