Java 嵌套流

Question

快速提问： 如何像这样引用嵌套流的父元素：

jpegDir.stream()
    .parallel()
    .map(E -> createDimentionArray(E.getDescription(1), E.getDescription(3)))
    .filter(E -> E != null)
    .forEach(E -> images.stream()
        .filter(J -> J.getType().contains(".jpg"))
        .forEach(I -> I.setSize(E))
    );

最后一个forEach 的父元素E 的类型为string。有没有办法让我在 setSize() 方法中引用 E ？

Answer 1

更新

只是贴出固定的代码，其他人有问题可以看看：

public class Inderxer {

  public void indexFolder(Path path) throws IOException {
      List<Image> images = new LinkedList<>();
       Files.walk(path).parallel().forEach(E -> {
        if (!E.toFile().isDirectory() && !E.toFile().getName().contains(".DS") && FilenameUtils.getExtension(E.toFile().toString()) != ".kmz") {
            try {

                Metadata metadata = ImageMetadataReader.readMetadata(E.toFile());
                if (FilenameUtils.getExtension(E.toFile().toString()).contains("jpg")) {
                    List<Directory> dirs = metadata.getDirectoriesOfType(JpegDirectory.class).stream().collect(Collectors.toList());
                    images.add(new Image(E.getFileName().toString(), FilenameUtils.getExtension(E.toFile().toString()), dirs));
                } else {
                    List<Directory> dirs = metadata.getDirectoriesOfType(PngDirectory.class).stream().collect(Collectors.toList());
                    images.add(new Image(E.getFileName().toString(), FilenameUtils.getExtension(E.toFile().toString()), dirs));
                }

            } catch (ImageProcessingException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    });
    images.stream()
            .forEach(M -> M.getDirectory().stream()
                    .forEach(D -> {
                        if (!M.getType().equals("png")) {
                            M.setSize(createDimentionArray(D.getDescription(1), D.getDescription(3), "jpg"));
                        } else {
                            M.setSize(createDimentionArray(D.getDescription(1), D.getDescription(2), "png"));
                        }
                    }));

    images.forEach(System.out::println);
}

private String createDimentionArray(String h, String w, String type) {
    String res = "";
    if (type.equals("jpg")) {
        if (h != null && w != null) {
            String[] hsplit = h.split("pixels");
            String[] wsplit = w.split("pixels");
            if (hsplit[0] != null && wsplit[0] != null) {
                res = hsplit[0]; //Hight
                res += wsplit[0]; //Width
                res += "\n";
            }
            return res;
        } else {
            return null;
        }

    } else {
        if (h != null && w != null) {
            String[] hsplit = h.split("pixels");
            String[] wsplit = w.split("pixels");
            if (hsplit[0] != null && wsplit[0] != null) {
                res = hsplit[0]; //Hight
                res += " ";
                res += wsplit[0]; //Width
                res += "\n";
            }
            return res;
        } else {
            return null;
        }
    }
  }
}