1/**
2 * Copyright 2007 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.tonicsystems.jarjar;
18
19import java.io.File;
20import java.lang.reflect.InvocationTargetException;
21import java.lang.reflect.Method;
22import java.util.ArrayList;
23import java.util.List;
24
25class MainUtil
26{
27    public static void runMain(Object main, String[] args, String defCommand) throws Exception {
28        if (args.length > 0) {
29            String command = args[0];
30            Method[] methods = main.getClass().getMethods();
31            for (int i = 0; i < methods.length; i++) {
32                Method method = methods[i];
33                if (method.getName().equals(command)) {
34                    String[] remaining = new String[args.length - 1];
35                    System.arraycopy(args, 1, remaining, 0, remaining.length);
36                    try {
37                        method.invoke(main, bindParameters(method, remaining));
38                    } catch (InvocationTargetException e) {
39                        Throwable cause = e.getCause();
40                        if (cause instanceof IllegalArgumentException) {
41                            System.err.println("Syntax error: " + cause.getMessage());
42                        } else if (cause instanceof Exception) {
43                            throw (Exception) cause;
44                        } else {
45                            throw e;
46                        }
47                    }
48                    return;
49                }
50            }
51        }
52        if (defCommand != null)
53            runMain(main, new String[]{ defCommand }, null);
54    }
55
56    private static Object[] bindParameters(Method method, String[] args) {
57        List<Object> parameters = new ArrayList<Object>();
58        Class[] parameterTypes = method.getParameterTypes();
59        for (int i = 0, len = parameterTypes.length; i < len; i++) {
60            Class type = parameterTypes[i];
61            int remaining = Math.max(0, args.length - i);
62            if (type.equals(String[].class)) {
63                String[] rest = new String[remaining];
64                System.arraycopy(args, 1, rest, 0, remaining);
65                parameters.add(rest);
66            } else if (remaining > 0) {
67                parameters.add(convertParameter(args[i], parameterTypes[i]));
68            } else {
69                parameters.add(null);
70            }
71        }
72        return parameters.toArray();
73    }
74
75    private static Object convertParameter(String arg, Class type) {
76        if (type.equals(String.class)) {
77            return arg;
78        } else if (type.equals(Integer.class)) {
79            return Integer.valueOf(arg, 10);
80        } else if (type.equals(File.class)) {
81            return new File(arg);
82        } else {
83            throw new UnsupportedOperationException("Unknown type " + type);
84        }
85    }
86}
87