001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019 020 package javax.activation; 021 022 import java.beans.Beans; 023 import java.io.Externalizable; 024 import java.io.IOException; 025 import java.io.ObjectInputStream; 026 027 /** 028 * @version $Rev: 467553 $ $Date: 2006-10-25 06:01:51 +0200 (Mi, 25. Okt 2006) $ 029 */ 030 public class CommandInfo { 031 private final String commandName; 032 private final String commandClass; 033 034 /** 035 * Constructor for a CommandInfo 036 * 037 * @param commandName the command name 038 * @param commandClass the name of the command's implementation class 039 */ 040 public CommandInfo(String commandName, String commandClass) { 041 this.commandName = commandName; 042 this.commandClass = commandClass; 043 } 044 045 /** 046 * Return the command name. 047 * 048 * @return the command name 049 */ 050 public String getCommandName() { 051 return commandName; 052 } 053 054 /** 055 * Return the implementation class name. 056 * 057 * @return the name of the command's implementation class; may be null 058 */ 059 public String getCommandClass() { 060 return commandClass; 061 } 062 063 /** 064 * Instantiate and return a command JavaBean. 065 * The bean is created using Beans.instantiate(loader, commandClass). 066 * If the new bean implements CommandObject then its setCommandContext(String, DataHandler) 067 * method is called. 068 * Otherwise if it implements Externalizable and the supplied DataHandler is not null 069 * then its readExternal(ObjectInputStream) method is called with a stream obtained from 070 * DataHandler.getInputStream(). 071 * 072 * @param dh a DataHandler that provides the data to be passed to the command 073 * @param loader the ClassLoader to be used to instantiate the command 074 * @return a new command instance 075 * @throws IOException if there was a problem initializing the command 076 * @throws ClassNotFoundException if the command class could not be found 077 */ 078 public Object getCommandObject(DataHandler dh, ClassLoader loader) throws IOException, ClassNotFoundException { 079 Object bean = Beans.instantiate(loader, commandClass); 080 if (bean instanceof CommandObject) { 081 ((CommandObject) bean).setCommandContext(commandName, dh); 082 } else if (bean instanceof Externalizable && dh != null) { 083 ((Externalizable) bean).readExternal(new ObjectInputStream(dh.getInputStream())); 084 } 085 return bean; 086 } 087 }