SystemOperation.java

package org.act.tstream.container;

import java.io.IOException;

import org.apache.commons.io.IOUtils;
import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.Logger;

public class SystemOperation {

	public static final Logger LOG = Logger.getLogger(SystemOperation.class);

	public static boolean isRoot() throws IOException {
		String result = SystemOperation.exec("echo $EUID").substring(0, 1);
		return Integer.valueOf(result.substring(0, result.length())).intValue() == 0 ? true
				: false;
	};

	public static void mount(String name, String target, String type,
			String data) throws IOException {
		StringBuilder sb = new StringBuilder();
		sb.append("mount -t ").append(type).append(" -o ").append(data)
				.append(" ").append(name).append(" ").append(target);
		SystemOperation.exec(sb.toString());
	}

	public static void umount(String name) throws IOException {
		StringBuilder sb = new StringBuilder();
		sb.append("umount ").append(name);
		SystemOperation.exec(sb.toString());
	}

	public static String exec(String cmd) throws IOException {
		LOG.debug("Shell cmd: " + cmd);
		Process process = new ProcessBuilder(new String[] { "/bin/bash", "-c",
				cmd }).start();
		try {
			process.waitFor();
			String output = IOUtils.toString(process.getInputStream());
			String errorOutput = IOUtils.toString(process.getErrorStream());
			LOG.debug("Shell Output: " + output);
			if (errorOutput.length() != 0) {
				LOG.error("Shell Error Output: " + errorOutput);
				throw new IOException(errorOutput);
			}
			return output;
		} catch (InterruptedException ie) {
			throw new IOException(ie.toString());
		}

	}

	public static void main(String[] args) throws IOException {
		BasicConfigurator.configure();
		SystemOperation.mount("test", "/cgroup/cpu", "cgroup", "cpu");
	}

}