ProcessHelperImpl.java

/*********************************************************************
 Copyright 2015 the Flapi authors

 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 unquietcode.tools.flapi.examples.pipes;

import unquietcode.tools.flapi.examples.pipes.builder.Process.ProcessHelper;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;

/**
 * @author Ben Fagin
 * @version 02-05-2013
 */
public class ProcessHelperImpl implements ProcessHelper {
	private String processName;
	private final List<String> arguments = new ArrayList<String>();
	private final List<ProcessHelperImpl> processChain;


	public ProcessHelperImpl() {
		this(new ArrayList<ProcessHelperImpl>());
	}

	protected ProcessHelperImpl(List<ProcessHelperImpl> chain) {
		this.processChain = chain;
		processChain.add(this);
	}

	@Override
	public void withProcess(String name) {
		processName = name;
	}

	@Override
	public void addArgument(String argument) {
		arguments.add(argument);
	}

	@Override
	public void addArgument(String name, String value) {
		arguments.add(name);
		arguments.add(value);
	}

	@Override
	public void pipe(AtomicReference<ProcessHelper> _helper1) {
		_helper1.set(new ProcessHelperImpl(processChain));
	}

	@Override
	public InputStream run() {
		List<Process> chain = new ArrayList<Process>();

		for (ProcessHelperImpl helper : processChain) {
			List<String> commandString = new ArrayList<String>();
			commandString.add(helper.processName);
			commandString.addAll(helper.arguments);
			String[] cmd = commandString.toArray(new String[commandString.size()]);

			try {
				Process p = Runtime.getRuntime().exec(cmd);
				chain.add(p);
			} catch (Exception ex) {
				throw new RuntimeException(ex);
			}
		}

		Process processes[] = chain.toArray(new Process[chain.size()]);

		if (processes.length == 1) {
			return processes[0].getInputStream();
		} else {
			try {
				return Piper.pipe(processes);
			} catch (Exception ex) {
				throw new RuntimeException(ex);
			}
		}
	}
}