    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    }