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
018package org.apache.commons.net.examples;
019
020import java.io.InputStream;
021import java.lang.reflect.InvocationTargetException;
022import java.lang.reflect.Method;
023import java.security.CodeSource;
024import java.util.Collections;
025import java.util.List;
026import java.util.Properties;
027
028/**
029 * Helper application for example classes.
030 */
031public class Main {
032
033    private static boolean fromJar() {
034        final CodeSource codeSource = Main.class.getProtectionDomain().getCodeSource();
035        if (codeSource != null) {
036            return codeSource.getLocation().getFile().endsWith(".jar");
037        }
038        return false; // No idea if this can happen
039    }
040
041    /**
042     * Helper application for example classes. Lists available classes, and provides shorthand invocation. For example:<br>
043     * <code>java -jar commons-net-examples-m.n.jar FTPClientExample -l host user password</code>
044     *
045     * @param args the first argument is used to name the class; remaining arguments are passed to the target class.
046     * @throws Throwable if an error occurs
047     */
048    public static void main(final String[] args) throws Throwable {
049        final Properties fp = new Properties();
050        final InputStream ras = Main.class.getResourceAsStream("examples.properties");
051        if (ras != null) {
052            fp.load(ras);
053        } else {
054            System.err.println("[Cannot find examples.properties file, so aliases cannot be used]");
055        }
056        if (args.length == 0) {
057            if (Thread.currentThread().getStackTrace().length > 2) { // called by Maven
058                System.out.println(
059                        "Usage: mvn -q exec:java  -Dexec.arguments=<alias or" + " exampleClass>,<exampleClass parameters> (comma-separated, no spaces)");
060                System.out.println("Or   : mvn -q exec:java  -Dexec.args=\"<alias" + " or exampleClass> <exampleClass parameters>\" (space separated)");
061            } else if (fromJar()) {
062                System.out.println("Usage: java -jar commons-net-examples-m.n.jar <alias or exampleClass> <exampleClass parameters>");
063            } else {
064                System.out
065                        .println("Usage: java -cp target/classes org.apache.commons.net.examples.Main" + " <alias or exampleClass> <exampleClass parameters>");
066            }
067            @SuppressWarnings("unchecked") // property names are Strings
068            final List<String> l = (List<String>) Collections.list(fp.propertyNames());
069            if (l.isEmpty()) {
070                return;
071            }
072            l.sort(null);
073            System.out.println("\nAliases and their classes:");
074            for (final String s : l) {
075                System.out.printf("%-25s %s%n", s, fp.getProperty(s));
076            }
077            return;
078        }
079
080        final String shortName = args[0];
081        String fullName = fp.getProperty(shortName);
082        if (fullName == null) {
083            fullName = shortName;
084        }
085        try {
086            final Class<?> clazz = Class.forName(fullName);
087            final Method m = clazz.getDeclaredMethod("main", args.getClass());
088            final String[] args2 = new String[args.length - 1];
089            System.arraycopy(args, 1, args2, 0, args2.length);
090            try {
091                m.invoke(null, (Object) args2);
092            } catch (final InvocationTargetException ite) {
093                final Throwable cause = ite.getCause();
094                if (cause != null) {
095                    throw cause;
096                }
097                throw ite;
098            }
099        } catch (final ClassNotFoundException e) {
100            System.out.println(e);
101        }
102    }
103}