src/main/java/com/android/tools/r8/utils/ZipUtils.java

// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
package com.android.tools.r8.utils;

import com.android.tools.r8.errors.CompilationError;
import com.google.common.io.ByteStreams;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;
import java.util.function.Predicate;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class ZipUtils {

  public interface OnEntryHandler {
    void onEntry(ZipEntry entry, ZipInputStream input) throws IOException;
  }

  public static void iter(String zipFile, OnEntryHandler handler) throws IOException {
    try (ZipInputStream input = new ZipInputStream(new FileInputStream(zipFile))){
      ZipEntry entry;
      while ((entry = input.getNextEntry()) != null) {
        handler.onEntry(entry, input);
      }
    }
  }

  public static List<File> unzip(String zipFile, File outDirectory) throws IOException {
    return unzip(zipFile, outDirectory, (entry) -> true);
  }

  public static List<File> unzip(String zipFile, File outDirectory, Predicate<ZipEntry> filter)
      throws IOException {
    final Path outDirectoryPath = outDirectory.toPath();
    final List<File> outFiles = new ArrayList<>();
      iter(zipFile, (entry, input) -> {
        String name = entry.getName();
        if (!entry.isDirectory() && filter.test(entry)) {
          if (name.contains("..")) {
            // Protect against malicious archives.
            throw new CompilationError("Invalid entry name \"" + name + "\"");
          }
          Path outPath = outDirectoryPath.resolve(name);
          File outFile = outPath.toFile();
          outFile.getParentFile().mkdirs();
          FileOutputStream output = new FileOutputStream(outFile);
          ByteStreams.copy(input, output);
          outFiles.add(outFile);
        }
      });
    return outFiles;
  }
}