001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.xbean.command;
018    
019    import java.util.HashMap;
020    import java.util.Iterator;
021    import java.util.Map;
022    
023    public class CommandRegistry {
024        
025        protected static final HashMap commands = new HashMap();
026    
027        static {
028            loadCommandList();
029        }
030    
031        protected static final CommandRegistry unknownCommand = new CommandRegistry();
032    
033        public static Map getCommandMap() {
034            HashMap rc = new HashMap();
035            for (Iterator iter = commands.keySet().iterator(); iter.hasNext();) {
036                String name = (String) iter.next();
037                Command command = getCommand(name);
038                rc.put(name, command);
039            }
040            return rc;
041        }
042    
043        public static void register(String name, Command cmd) {
044            commands.put(name, cmd);
045        }
046    
047        public static void register(String name, Class cmd) {
048            commands.put(name, cmd);
049        }
050    
051        public static Command getCommand(String name) {
052            Object cmd = commands.get(name);
053            if (cmd instanceof Class) {
054                cmd = loadCommand((Class) cmd);
055                register(name, (Command) cmd);
056            }
057            return (Command) cmd;
058        }
059    
060    
061        // - Protected methods - //
062        protected static Command loadCommand(Class commandClass) {
063            Command cmd = null;
064            try {
065                cmd = (Command) commandClass.newInstance();
066            } catch (Exception e) {
067                //throw new IOException("Cannot instantiate command class "+commandClass+"\n"+e.getClass().getName()+":\n"+e.getMessage());
068            }
069            return cmd;
070        }
071    
072        /**
073         * TODO: Replace this part with the classpath magic
074         */
075        protected static void loadCommandList() {
076            Exit.register();
077            Help.register();
078            Lookup.register();
079            Version.register();
080            GroovySh.register();
081        }
082    }