Yo APIからのcallbackでコマンド等を実行

Callback.java

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/callback")
public class Callback extends HttpServlet {
	private static final long serialVersionUID = 1L;

	public Callback() {
		super();
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		PrintWriter out = response.getWriter();
		String username = request.getParameter("username");
		response.setContentType("text/html;charset=UTF8");
		if (username != null && !username.isEmpty()) {
			try {
				Runtime runtime = Runtime.getRuntime();
				runtime.exec("/path/to/command " + username);
			} catch (IOException e) {
				e.printStackTrace();
			}
			response.setStatus(HttpServletResponse.SC_OK);
			out.println("ok");
		} else {
			response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Bad Request (username not set)");
		}
	}
}