001    /*
002     * Copyright (C) 2012 eXo Platform SAS.
003     *
004     * This is free software; you can redistribute it and/or modify it
005     * under the terms of the GNU Lesser General Public License as
006     * published by the Free Software Foundation; either version 2.1 of
007     * the License, or (at your option) any later version.
008     *
009     * This software is distributed in the hope that it will be useful,
010     * but WITHOUT ANY WARRANTY; without even the implied warranty of
011     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012     * Lesser General Public License for more details.
013     *
014     * You should have received a copy of the GNU Lesser General Public
015     * License along with this software; if not, write to the Free
016     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018     */
019    package org.crsh.shell.impl.command;
020    
021    import org.crsh.console.KeyHandler;
022    import org.crsh.shell.ShellProcess;
023    import org.crsh.shell.ShellProcessContext;
024    import org.crsh.shell.ShellResponse;
025    
026    import java.util.logging.Level;
027    
028    abstract class CRaSHProcess implements ShellProcess {
029    
030      /** . */
031      protected final CRaSHSession crash;
032    
033      /** . */
034      protected final String request;
035    
036      /** . */
037      private volatile Thread thread;
038    
039      /** . */
040      private volatile boolean cancelled;
041    
042      protected CRaSHProcess(CRaSHSession crash, String request) {
043        this.crash = crash;
044        this.request = request;
045      }
046    
047      public void execute(ShellProcessContext processContext) {
048        ClassLoader previous = crash.setCRaSHLoader();
049        try {
050          ShellResponse resp;
051          thread = Thread.currentThread();
052    
053          //
054          String userName = crash.user != null ? crash.user.getName() : "unauthenticated";
055          CRaSHSession.accessLog.log(Level.FINE, "User " + userName + " executes " + request);
056    
057          //
058          try {
059            try {
060              resp = doInvoke(processContext);
061              if (Thread.interrupted() || cancelled) {
062                throw new InterruptedException("like a goto");
063              }
064            }
065            catch (InterruptedException e) {
066              Thread.currentThread().interrupt();
067              resp = ShellResponse.cancelled();
068            }
069          } catch (Throwable t) {
070            resp = ShellResponse.internalError("Unexpected error when executing process", t);
071          } finally {
072            thread = null;
073          }
074    
075          //
076          processContext.end(resp);
077    
078          //
079          if (resp instanceof ShellResponse.Error) {
080            ShellResponse.Error error = (ShellResponse.Error)resp;
081            Throwable t = error.getThrowable();
082            if (t != null) {
083              CRaSHSession.log.log(Level.SEVERE, "Error while evaluating request '" + request + "' " + error.getMessage(), t);
084            } else {
085              CRaSHSession.log.log(Level.SEVERE, "Error while evaluating request '" + request + "' " + error.getMessage());
086            }
087          }
088        }
089        finally {
090          crash.setPreviousLoader(previous);
091        }
092      }
093    
094      @Override
095      public KeyHandler getKeyHandler() {
096        return null;
097      }
098    
099      abstract ShellResponse doInvoke(ShellProcessContext context) throws InterruptedException;
100    
101      public void cancel() {
102        ClassLoader previous = crash.setCRaSHLoader();
103        try {
104          Thread t = thread;
105          if (t != null) {
106            t.interrupt();
107          }
108          cancelled = true;
109        }
110        finally {
111          crash.setPreviousLoader(previous);
112        }
113      }
114    }