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 */ 019 020 package org.crsh.shell.impl.command.pipeline; 021 022 import org.crsh.command.CommandContext; 023 import org.crsh.shell.ErrorKind; 024 import org.crsh.shell.impl.command.spi.CommandException; 025 import org.crsh.shell.impl.command.spi.CommandInvoker; 026 import org.crsh.keyboard.KeyHandler; 027 028 import java.io.IOException; 029 030 public class PipeLine extends CommandInvoker<Void, Object> { 031 032 /** . */ 033 private final CommandInvoker[] invokers; 034 035 /** . */ 036 private CommandContext<?> current; 037 038 public PipeLine(CommandInvoker[] invokers) { 039 this.invokers = invokers; 040 this.current = null; 041 } 042 043 public Class<Void> getConsumedType() { 044 return Void.class; 045 } 046 047 public Class<Object> getProducedType() { 048 return Object.class; 049 } 050 051 public void open(CommandContext<? super Object> consumer) throws IOException, CommandException { 052 open(0, consumer); 053 } 054 055 private CommandContext open(final int index, final CommandContext last) throws IOException, CommandException { 056 if (index < invokers.length) { 057 058 // 059 final CommandInvoker invoker = invokers[index]; 060 CommandContext next = open(index + 1, last); 061 062 // 063 Class produced = invoker.getProducedType(); 064 Class<?> consumed = invoker.getConsumedType(); 065 CommandInvokerAdapter filterContext = new CommandInvokerAdapter(invoker, consumed, produced); 066 try { 067 filterContext.open(next); 068 } 069 catch (Exception e) { 070 throw new CommandException(ErrorKind.EVALUATION, e); 071 } 072 073 // Save current filter in field 074 // so if anything wrong happens it will be closed 075 current = filterContext; 076 077 // 078 return filterContext; 079 } else { 080 current = last; 081 return last; 082 } 083 } 084 085 @Override 086 public KeyHandler getKeyHandler() { 087 for (CommandInvoker<?, ?> invoker : invokers) { 088 KeyHandler handler = invoker.getKeyHandler(); 089 if (handler != null) { 090 return handler; 091 } 092 } 093 return null; 094 } 095 096 public void provide(Void element) throws IOException { 097 // Ignore 098 } 099 100 public void flush() throws IOException { 101 current.flush(); 102 } 103 104 public void close() throws IOException, CommandException { 105 try { 106 current.close(); 107 } 108 catch (Exception e) { 109 throw new CommandException(ErrorKind.EVALUATION, e); 110 } 111 } 112 }