1// Copyright 2018 Google Inc. All rights reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package main
16
17import (
18	"archive/zip"
19	"flag"
20	"fmt"
21	"io/ioutil"
22	"log"
23	"os"
24	"path/filepath"
25	"sort"
26	"strings"
27)
28
29var (
30	outputFile = flag.String("o", "", "output file")
31	prefix     = flag.String("prefix", "", "prefix for each entry in the output file")
32	inputFile  = flag.String("i", "", "input jar or srcjar")
33)
34
35func must(err error) {
36	if err != nil {
37		log.Fatal(err)
38	}
39}
40
41func fileToPackage(file string) string {
42	dir := filepath.Dir(file)
43	return strings.Replace(dir, "/", ".", -1)
44}
45
46func main() {
47	flag.Usage = func() {
48		fmt.Fprintln(os.Stderr, "usage: extract_jar_packages -i <input file> -o <output -file> [-prefix <prefix>]")
49		flag.PrintDefaults()
50	}
51
52	flag.Parse()
53
54	if *outputFile == "" || *inputFile == "" {
55		flag.Usage()
56		os.Exit(1)
57	}
58
59	pkgSet := make(map[string]bool)
60
61	reader, err := zip.OpenReader(*inputFile)
62	if err != nil {
63		log.Fatal(err)
64	}
65	defer reader.Close()
66
67	for _, f := range reader.File {
68		ext := filepath.Ext(f.Name)
69		if ext == ".java" || ext == ".class" {
70			pkgSet[fileToPackage(f.Name)] = true
71		}
72	}
73
74	var pkgs []string
75	for k := range pkgSet {
76		pkgs = append(pkgs, k)
77	}
78	sort.Strings(pkgs)
79
80	var data []byte
81	for _, pkg := range pkgs {
82		data = append(data, *prefix...)
83		data = append(data, pkg...)
84		data = append(data, "\n"...)
85	}
86
87	must(ioutil.WriteFile(*outputFile, data, 0666))
88}
89