    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
    019package examples;
    020
    021import java.lang.reflect.Method;
    022import java.security.CodeSource;
    023import java.util.Enumeration;
    024import java.util.HashMap;
    025import java.util.Map;
    026import java.util.jar.JarEntry;
    027import java.util.jar.JarFile;
    028
    029public 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}