java - JAR 文件中的 walkFileThree

Question

我无法获取 JAR 文件中的根路径。我正在编写一种使用 Java NIO walkFileThree 将 Jar/Zip 文件的内容提取到目标目录的方法。该方法目前看起来像这样:

public static void unzip(Path filePath, Path destination) throws IOException {
Map<String, String> zipProperties = new HashMap<>();
/* We want to read an existing ZIP File, so we set this to False */
zipProperties.put("create", "false");
zipProperties.put("encoding", "UTF-8");
URI zipFile = URI.create("jar:file:" + filePath.toUri().getPath());

try (FileSystem zipfs = FileSystems.newFileSystem(zipFile, zipProperties)) {
  Path rootPath = zipfs.getPath("/");
  Files.walkFileTree(rootPath, new SimpleFileVisitor<Path>() {

    @Override
    public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {

      Path targetPath = destination.resolve(rootPath.relativize(dir));
      if (!Files.exists(targetPath)) {
        Files.createDirectory(targetPath);
      }
      return FileVisitResult.CONTINUE;
    }

    @Override
    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {

      Files.copy(file, destination.resolve(rootPath.relativize(file)), StandardCopyOption.COPY_ATTRIBUTES, StandardCopyOption.REPLACE_EXISTING);
      return FileVisitResult.CONTINUE;
    }
  });
}
}

但我得到一个异常(exception):

java.nio.file.ProviderMismatchException
at sun.nio.fs.UnixPath.toUnixPath(UnixPath.java:200) ~[?:1.8.0_45]
at sun.nio.fs.UnixPath.resolve(UnixPath.java:397) ~[?:1.8.0_45]
at sun.nio.fs.UnixPath.resolve(UnixPath.java:43) ~[?:1.8.0_45]

获取 zip 文件的根路径 (/) 以便我可以递归地将所有内容复制到目标文件夹的正确方法是什么？

谢谢!

Answer 1

得到它的工作，只是按照此处的建议在 relativize() 之后添加了一个 toString():FileSystemNotFoundException

现在的工作代码如下所示:

public static void unzip(Path filePath, Path destination) throws IOException {
  //Path filePath = Paths.get( zipFilePath );
  Map<String, String> zipProperties = new HashMap<>();
 /* We want to read an existing ZIP File, so we set this to False */
 zipProperties.put("create", "false");
 zipProperties.put("encoding", "UTF-8");
 URI zipFile = URI.create("jar:file:" + filePath.toUri().getPath());

  try (FileSystem zipfs = FileSystems.newFileSystem(zipFile, zipProperties)) {
  Path rootPath = zipfs.getPath("/");
  Files.walkFileTree(rootPath, new SimpleFileVisitor<Path>() {

    @Override
    public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {

      Path targetPath = destination.resolve(rootPath.relativize(dir).toString());
      if (!Files.exists(targetPath)) {
        Files.createDirectory(targetPath);
      }
      return FileVisitResult.CONTINUE;
    }

    @Override
    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {

      Files.copy(file, destination.resolve(rootPath.relativize(file).toString()), StandardCopyOption.COPY_ATTRIBUTES, StandardCopyOption.REPLACE_EXISTING);
      return FileVisitResult.CONTINUE;
    }
  });
 }
}