如何使用ImageJ中的线程打开文件夹？ （JAVA）

Question

as part of a project in my ImageJ plugin, I need to open up to 3000 images as an ImageStack. The user selects a folder containing all the files with

DirectoryChooser dirChoos = new DirectoryChooser("Select Folder");
String filePath = dirChoos.getDirectory();

My current method of opening the files is with

FolderOpener opener = new FolderOpener();
ImagePlus imp = opener.openFolder(filePath);
ImageStack stack = imp.getImageStack();

This works, however for larger folders this adds 4 or 5 minutes on to plugins running time. While I understand that opening large folders obviously takes more time, it would be nice if I could cut it down a bit.

The method I am trying to implement is

File folder = new File(filePath);
String[] listOfFiles = Folder.list();
Arrays.sort(listOfFiles); //　to make sure the stack is in the right order

By splitting it listOfFiles using Arrays.copyOfRange (into 3 for argument's sake) and into parts and passing them to an object that extends Thread

openFolder r1 = new openFolder(listOfFiles_part1);
openFolder r2 = new openFolder(listOfFiles_part2);
openFolder r3 = new openFolder(listOfFiles_part3);

new Thread(r1).start();
new Thread(r2).start();
new Thread(r3).start();

openFolder's method uses listOfFiles_part to form an array of ImagePlus instances from the files

int len = Array.getLength(listOfFiles_part)
ImagePlus[] impArray = new ImagePlus[len];
for (int a = 0; a < len; a++ ) {
     impArray[a] = new ImagePlus((listOfFiles_part[a]).getPath());
}

then, the impArrays are returned, and an ImageStack is formed from the arrays.

However, this does seem like a bit of an obtuse method and I haven't had too much luck implementing as of now.

Are there any better ways to use threads to get an ImageStack from the folder? (Would using threads even necessarily speed up the process?)

Any help would be appreciated. Cheers

Answer 1

There is more one approach. If you use java 8 the parallel approach is the simplier

List<ImagePlus> impArray = new ArrayList<ImagePlus>();
listOfFiles_part.parallelStream()
.forEachOrdered(i -> impArray.add(new ImagePlus(i.getPath()));

Otherwise you may used threadpool because you don't know the optimized number of thread depending of the hardware.