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.lang.java;
020
021 import org.crsh.cli.descriptor.CommandDescriptor;
022 import org.crsh.cli.impl.descriptor.HelpDescriptor;
023 import org.crsh.cli.impl.invocation.InvocationMatch;
024 import org.crsh.cli.impl.lang.CommandFactory;
025 import org.crsh.cli.impl.lang.Instance;
026 import org.crsh.cli.impl.lang.ObjectCommandInvoker;
027 import org.crsh.cli.spi.Completer;
028 import org.crsh.command.BaseCommand;
029 import org.crsh.shell.impl.command.spi.CommandCreationException;
030 import org.crsh.command.InvocationContext;
031 import org.crsh.command.Pipe;
032 import org.crsh.command.RuntimeContext;
033 import org.crsh.shell.ErrorType;
034 import org.crsh.shell.impl.command.spi.Command;
035 import org.crsh.shell.impl.command.spi.ShellCommand;
036 import org.crsh.util.Utils;
037
038 import java.lang.reflect.Type;
039
040 /** @author Julien Viet */
041 public class ShellCommandImpl<T extends BaseCommand> extends ShellCommand<Instance<T>> {
042
043 /** . */
044 private final Class<T> clazz;
045
046 /** . */
047 private final CommandDescriptor<Instance<T>> descriptor;
048
049 public ShellCommandImpl(Class<T> clazz) {
050 CommandFactory factory = new CommandFactory(getClass().getClassLoader());
051 this.clazz = clazz;
052 this.descriptor = HelpDescriptor.create(factory.create(clazz));
053 }
054
055 public CommandDescriptor<Instance<T>> getDescriptor() {
056 return descriptor;
057 }
058
059 protected Completer getCompleter(final RuntimeContext context) throws CommandCreationException {
060 final T command = createCommand();
061 if (command instanceof Completer) {
062 command.context = context;
063 return (Completer)command;
064 } else {
065 return null;
066 }
067 }
068
069 @Override
070 protected Command<?, ?> resolveCommand(InvocationMatch<Instance<T>> match) {
071
072 // Cast to the object invoker
073 org.crsh.cli.impl.invocation.CommandInvoker<Instance<T>,?> invoker = match.getInvoker();
074
075 // Do we have a pipe command or not ?
076 if (Pipe.class.isAssignableFrom(invoker.getReturnType())) {
077 org.crsh.cli.impl.invocation.CommandInvoker tmp = invoker;
078 return getPipeInvoker(tmp);
079 } else {
080
081 // Determine the produced type
082 Class<?> producedType;
083 if (void.class.equals(invoker.getReturnType())) {
084 producedType = Object.class;
085 } else {
086 producedType = invoker.getReturnType();
087 }
088
089 // Override produced type from InvocationContext<P> if any
090 if (invoker instanceof ObjectCommandInvoker) {
091 ObjectCommandInvoker<T, ?> objectInvoker = (ObjectCommandInvoker<T, ?>)invoker;
092 Class<?>[] parameterTypes = objectInvoker.getParameterTypes();
093 for (int i = 0;i < parameterTypes.length;i++) {
094 Class<?> parameterType = parameterTypes[i];
095 if (InvocationContext.class.isAssignableFrom(parameterType)) {
096 Type contextGenericParameterType = objectInvoker.getGenericParameterTypes()[i];
097 producedType = Utils.resolveToClass(contextGenericParameterType, InvocationContext.class, 0);
098 break;
099 }
100 }
101 }
102
103 //
104 return getProducerInvoker(invoker, producedType);
105 }
106 }
107
108 T createCommand() throws CommandCreationException {
109 T command;
110 try {
111 command = clazz.newInstance();
112 }
113 catch (Exception e) {
114 String name = clazz.getSimpleName();
115 throw new CommandCreationException(name, ErrorType.INTERNAL, "Could not create command " + name + " instance", e);
116 }
117 return command;
118 }
119
120 private <C, P, PC extends Pipe<C, P>> Command<C, P> getPipeInvoker(final org.crsh.cli.impl.invocation.CommandInvoker<Instance<T>, PC> invoker) {
121 return new PipeCommandImpl<T, C, P, PC>(this, invoker);
122 }
123
124 private <P> Command<Void, P> getProducerInvoker(final org.crsh.cli.impl.invocation.CommandInvoker<Instance<T>, ?> invoker, final Class<P> producedType) {
125 return new ProducerCommandImpl<T, P>(this, invoker, producedType);
126 }
127
128 }