1 files changed, 88 insertions, 0 deletions
diff --git a/cmd/extract_jar_packages/extract_jar_packages.go b/cmd/extract_jar_packages/extract_jar_packages.go
new file mode 100644
index 00000000..fca308ff
--- /dev/null
+++ b/cmd/extract_jar_packages/extract_jar_packages.go
@@ -0,0 +1,88 @@
+// Copyright 2018 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"archive/zip"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+var (
+	outputFile = flag.String("o", "", "output file")
+	prefix     = flag.String("prefix", "", "prefix for each entry in the output file")
+	inputFile  = flag.String("i", "", "input jar or srcjar")
+)
+
+func must(err error) {
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func fileToPackage(file string) string {
+	dir := filepath.Dir(file)
+	return strings.Replace(dir, "/", ".", -1)
+}
+
+func main() {
+	flag.Usage = func() {
+		fmt.Fprintln(os.Stderr, "usage: extract_jar_packages -i <input file> -o <output -file> [-prefix <prefix>]")
+		flag.PrintDefaults()
+	}
+
+	flag.Parse()
+
+	if *outputFile == "" || *inputFile == "" {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	pkgSet := make(map[string]bool)
+
+	reader, err := zip.OpenReader(*inputFile)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer reader.Close()
+
+	for _, f := range reader.File {
+		ext := filepath.Ext(f.Name)
+		if ext == ".java" || ext == ".class" {
+			pkgSet[fileToPackage(f.Name)] = true
+		}
+	}
+
+	var pkgs []string
+	for k := range pkgSet {
+		pkgs = append(pkgs, k)
+	}
+	sort.Strings(pkgs)
+
+	var data []byte
+	for _, pkg := range pkgs {
+		data = append(data, *prefix...)
+		data = append(data, pkg...)
+		data = append(data, "\n"...)
+	}
+
+	must(ioutil.WriteFile(*outputFile, data, 0666))
+}