/** * Copyright (C) 2010 - 2016 52°North Initiative for Geospatial Open Source * Software GmbH * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * * If the program is linked with libraries which are licensed under one of * the following licenses, the combination of the program with the linked * library is not considered a "derivative work" of the program: * * • Apache License, version 2.0 * • Apache Software License, version 1.0 * • GNU Lesser General Public License, version 3 * • Mozilla Public License, versions 1.0, 1.1 and 2.0 * • Common Development and Distribution License (CDDL), version 1.0 * * Therefore the distribution of the program linked with libraries licensed * under the aforementioned licenses, is permitted by the copyright holders * if the distribution is compliant with both the GNU General Public * License version 2 and the aforementioned licenses. * * This program 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. */ package org.n52.wps.server.r.util; import java.io.IOException; import java.util.Arrays; import org.n52.wps.server.r.FilteredRConnection; import org.rosuda.REngine.REXP; import org.rosuda.REngine.REXPMismatchException; import org.rosuda.REngine.Rserve.RserveException; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class RConnector { private static final long START_ATTEMPT_SLEEP = 1000l; private static final int START_ATTEMP_COUNT = 5; private static Logger log = LoggerFactory.getLogger(RConnector.class); private RStarter starter; public RConnector(RStarter starter) { this.starter = starter; } public FilteredRConnection getNewConnection(boolean enableBatchStart, String host, int port, String user, String password) throws RserveException { FilteredRConnection con = null; log.debug("Creating new RConnection"); con = getNewConnection(enableBatchStart, host, port); // Login MUSST be the next request after connection // otherwise the connection is broken even if login is requested later if (con != null && con.needLogin()) { log.debug("Connection requires login... logging in with user {}", user); con.login(user, password); } RLogger.log(con, "New connection from WPS4R"); REXP info = con.eval("capture.output(sessionInfo())"); try { log.debug("NEW CONNECTION >>> sessionInfo:\n{}", Arrays.deepToString(info.asStrings())); } catch (REXPMismatchException e) { log.warn("Error creating session info.", e); } return con; } private FilteredRConnection getNewConnection(boolean enableBatchStart, String host, int port) throws RserveException { log.debug("New connection using batch = {} at {}:{}", enableBatchStart, host, port); FilteredRConnection con = null; try { con = new FilteredRConnection(host, port); } catch (RserveException rse) { log.error("Could not connect to RServe.", rse); if (rse.getMessage().startsWith("Cannot connect") && enableBatchStart) { log.info("Attempting to start RServe."); try { con = attemptStarts(host, port); } catch (Exception e) { log.error("Attempted to start Rserve and establish a connection failed", e); // Throwable#addSuppressed() only supported by Java 1.7+ // rse.addSuppressed(e); } } else throw rse; } if (con == null) throw new RserveException(null, "Cannot connect with Rserve, connection is null. Is Rserve configured for remote connections? It is not by default. See http://www.rforge.net/Rserve/doc.html"); return con; } private FilteredRConnection attemptStarts(String host, int port) throws InterruptedException, IOException, RserveException { this.starter.startR(); int attempt = 1; FilteredRConnection con = null; while (attempt <= START_ATTEMP_COUNT) { try { Thread.sleep(START_ATTEMPT_SLEEP); // wait for R to startup, // then establish connection con = new FilteredRConnection(host, port); break; } catch (RserveException rse) { if (attempt >= 5) { throw rse; } attempt++; } } return con; } }