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     */
018    
019    package examples;
020    
021    import java.lang.reflect.Method;
022    import java.security.CodeSource;
023    import java.util.Enumeration;
024    import java.util.HashMap;
025    import java.util.Map;
026    import java.util.jar.JarEntry;
027    import java.util.jar.JarFile;
028    
029    public class Main {
030    
031        /**
032         * Helper application for example classes.
033         * Lists available classes, and provides shorthand invocation.
034         * For example:<br/>
035         * <code>java -jar commons-net-examples-m.n.jar FTPClientExample -l host user password</code>
036         * 
037         * @param args the first argument is used to name the class; remaining arguments
038         * are passed to the target class.
039         * @throws Exception 
040         * @throws Exception 
041         */
042        public static void main(String[] args) throws Exception  {
043            if (args.length==0) {
044                System.out.println("Usage: java -jar examples.jar <exampleClass> <exampleClass parameters>");
045            }
046            CodeSource codeSource = Main.class.getProtectionDomain().getCodeSource();
047            Map<String, String> map = new HashMap<String, String>();
048            if ( codeSource != null) {
049                final String sourceFile = codeSource.getLocation().getFile();
050                if (sourceFile.endsWith(".jar")) {
051                    if (args.length==0) {
052                        System.out.println("\nClasses found in the jar:");
053                    }
054                    JarFile jf = new JarFile(sourceFile);
055                    Enumeration<JarEntry> e = jf.entries();
056                    while (e.hasMoreElements()) {
057                      JarEntry je = e.nextElement();
058                      String name = je.getName();
059                      if (!name.endsWith(".class") 
060                              || name.contains("$") // subclasses
061                              || name.equals("examples/nntp/NNTPUtils.class") // no main class
062                              || name.equals("examples/util/IOUtil.class") // no main class
063                              || name.equals("examples/Main.class")) {
064                          continue;
065                      }
066                      name = name.replace(".class", "");
067                      int lastSep = name.lastIndexOf('/');
068                      String alias = name.substring(lastSep+1);
069                      if (args.length==0) {
070                          System.out.printf("%-25s %s%n",alias,name);
071                      }
072                      map.put(alias, name);
073                    }
074                    jf.close();
075                }
076            }
077    
078            if (args.length==0) {
079                return;
080            }
081    
082            String shortName = args[0];
083            String fullName = map.get(shortName);
084            if (fullName == null) {
085                fullName = shortName;
086            }
087            fullName = fullName.replace('/', '.');
088            Class<?> clazz = Class.forName(fullName);
089            Method m = clazz.getDeclaredMethod("main", new Class[]{args.getClass()});
090            String[] args2 = new String[args.length-1];
091            System.arraycopy(args, 1, args2, 0, args2.length);
092            m.invoke(null, (Object)args2);
093        }
094    }