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.impl.java;
020
021 import org.crsh.cli.descriptor.CommandDescriptor;
022 import org.crsh.cli.impl.descriptor.HelpDescriptor;
023 import org.crsh.cli.impl.descriptor.IntrospectionException;
024 import org.crsh.cli.impl.invocation.InvocationMatch;
025 import org.crsh.cli.impl.lang.CommandFactory;
026 import org.crsh.cli.impl.lang.Instance;
027 import org.crsh.cli.impl.lang.ObjectCommandInvoker;
028 import org.crsh.cli.spi.Completer;
029 import org.crsh.command.BaseCommand;
030 import org.crsh.shell.ErrorKind;
031 import org.crsh.shell.impl.command.spi.Command;
032 import org.crsh.shell.impl.command.spi.CommandException;
033 import org.crsh.shell.impl.command.spi.CommandMatch;
034 import org.crsh.command.InvocationContext;
035 import org.crsh.command.Pipe;
036 import org.crsh.command.RuntimeContext;
037 import org.crsh.util.Utils;
038
039 import java.lang.reflect.InvocationTargetException;
040 import java.lang.reflect.Type;
041
042 /** @author Julien Viet */
043 public class ClassShellCommand<T extends BaseCommand> extends Command<Instance<T>> {
044
045 /** . */
046 private final Class<T> clazz;
047
048 /** . */
049 private final CommandDescriptor<Instance<T>> descriptor;
050
051 public ClassShellCommand(Class<T> clazz) throws IntrospectionException {
052 CommandFactory factory = new CommandFactory(getClass().getClassLoader());
053 this.clazz = clazz;
054 this.descriptor = HelpDescriptor.create(factory.create(clazz));
055 }
056
057 public CommandDescriptor<Instance<T>> getDescriptor() {
058 return descriptor;
059 }
060
061 protected Completer getCompleter(final RuntimeContext context) throws CommandException {
062 final T command = createCommand();
063 if (command instanceof Completer) {
064 command.context = context;
065 return (Completer)command;
066 } else {
067 return null;
068 }
069 }
070
071 @Override
072 protected CommandMatch<?, ?> resolve(InvocationMatch<Instance<T>> match) {
073
074 // Cast to the object invoker
075 org.crsh.cli.impl.invocation.CommandInvoker<Instance<T>,?> invoker = match.getInvoker();
076
077 // Do we have a pipe command or not ?
078 if (Pipe.class.isAssignableFrom(invoker.getReturnType())) {
079 org.crsh.cli.impl.invocation.CommandInvoker tmp = invoker;
080 return getPipeInvoker(tmp);
081 } else {
082
083 // Determine the produced type
084 Class<?> producedType;
085 if (void.class.equals(invoker.getReturnType())) {
086 producedType = Object.class;
087 } else {
088 producedType = invoker.getReturnType();
089 }
090
091 // Override produced type from InvocationContext<P> if any
092 if (invoker instanceof ObjectCommandInvoker) {
093 ObjectCommandInvoker<T, ?> objectInvoker = (ObjectCommandInvoker<T, ?>)invoker;
094 Class<?>[] parameterTypes = objectInvoker.getParameterTypes();
095 for (int i = 0;i < parameterTypes.length;i++) {
096 Class<?> parameterType = parameterTypes[i];
097 if (InvocationContext.class.isAssignableFrom(parameterType)) {
098 Type contextGenericParameterType = objectInvoker.getGenericParameterTypes()[i];
099 producedType = Utils.resolveToClass(contextGenericParameterType, InvocationContext.class, 0);
100 break;
101 }
102 }
103 }
104
105 //
106 return getProducerInvoker(invoker, producedType);
107 }
108 }
109
110 T createCommand() throws CommandException {
111 T command;
112 try {
113 command = clazz.getConstructor().newInstance();
114 }
115 catch (InvocationTargetException e) {
116 String name = clazz.getSimpleName();
117 throw new CommandException(ErrorKind.EVALUATION, "Could not create command " + name + " instance", e.getCause());
118 }
119 catch (Exception e) {
120 String name = clazz.getSimpleName();
121 throw new CommandException(ErrorKind.INTERNAL, "Could not create command " + name + " instance", e);
122 }
123 return command;
124 }
125
126 private <C, P, PC extends Pipe<C, P>> CommandMatch<C, P> getPipeInvoker(final org.crsh.cli.impl.invocation.CommandInvoker<Instance<T>, PC> invoker) {
127 return new PipeCommandMatch<T, C, P, PC>(this, invoker);
128 }
129
130 private <P> CommandMatch<Void, P> getProducerInvoker(final org.crsh.cli.impl.invocation.CommandInvoker<Instance<T>, ?> invoker, final Class<P> producedType) {
131 return new ProducerCommandMatch<T, P>(this, invoker, producedType);
132 }
133
134 }