sneedmc/libraries/launcher/org/multimc/EntryPoint.java

package org.multimc;/*
 * Copyright 2012-2017 MultiMC Contributors
 *
 * 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.
 */

import org.multimc.onesix.OneSixLauncher;

import java.io.*;
import java.nio.charset.Charset;

public class EntryPoint
{
	private enum Action
	{
		Proceed,
		Launch,
		Abort
	}

	public static void main(String[] args)
	{
		EntryPoint listener = new EntryPoint();
		int retCode = listener.listen();
		if (retCode != 0)
		{
			System.out.println("Exiting with " + retCode);
			System.exit(retCode);
		}
	}

	private Action parseLine(String inData) throws ParseException
	{
		String[] pair = inData.split(" ", 2);

		if(pair.length == 1)
		{
			String command = pair[0];
			if (pair[0].equals("launch"))
				return Action.Launch;

			else if (pair[0].equals("abort"))
				return Action.Abort;

			else throw new ParseException();
		}

		if(pair.length != 2)
			throw new ParseException();

		String command = pair[0];
		String param = pair[1];

		if(command.equals("launcher"))
		{
			if(param.equals("onesix"))
			{
				m_launcher = new OneSixLauncher();
				Utils.log("Using onesix launcher.");
				Utils.log();
				return Action.Proceed;
			}
			else
				throw new ParseException();
		}

		m_params.add(command, param);
		//System.out.println(command + " : " + param);
		return Action.Proceed;
	}

	public int listen()
	{
		BufferedReader buffer;
		try
		{
			buffer = new BufferedReader(new InputStreamReader(System.in, "UTF-8"));
		} catch (UnsupportedEncodingException e)
		{
			System.err.println("For some reason, your java does not support UTF-8. Consider living in the current century.");
			e.printStackTrace();
			return 1;
		}
		boolean isListening = true;
		boolean isAborted = false;
		// Main loop
		while (isListening)
		{
			String inData;
			try
			{
				// Read from the pipe one line at a time
				inData = buffer.readLine();
				if (inData != null)
				{
					Action a = parseLine(inData);
					if(a == Action.Abort)
					{
						isListening = false;
						isAborted = true;
					}
					if(a == Action.Launch)
					{
						isListening = false;
					}
				}
				else
				{
					isListening = false;
					isAborted = true;
				}
			}
			catch (IOException e)
			{
				System.err.println("Launcher ABORT due to IO exception:");
				e.printStackTrace();
				return 1;
			}
			catch (ParseException e)
			{
				System.err.println("Launcher ABORT due to PARSE exception:");
				e.printStackTrace();
				return 1;
			}
		}
		if(isAborted)
		{
			System.err.println("Launch aborted by MultiMC.");
			return 1;
		}
		if(m_launcher != null)
		{
			return m_launcher.launch(m_params);
		}
		System.err.println("No valid launcher implementation specified.");
		return 1;
	}

	private ParamBucket m_params = new ParamBucket();
	private org.multimc.Launcher m_launcher;
}