Question

I got a little problem.
I got a map (on android phone) called “Save”, in that folder I got several .txt files.

I know how to enter the folder, and I can read 1 txt file (hardcoded) but I want it to be dynamic.

I want somehting like this:

public void onClick(View v) {

             File root = Environment.getExternalStorageDirectory();

             save = root.toString()+"/Save/";

                if (save.startsWith("3_test")){
                    System.out.println("FOUND!");
                } else {
                    System.out.println("NOT FOUND!");
                }

        }

I got a txt file called 3_test.txt but he can’t find it this way, if I do it hardcoded it does find it.

The problem is that I don’t know how to “scan” all files in the folder Save and then put an “if” check over it.

Hope someone can help me with this.

Answer 1

I think your code won’t work in Java either: your save variable contais the path to the folder Save, under de root folder.
To achieve a filtered directory listing, you can try using the list() method on the File object for the Save folder, passing a custom java.io.FilenameFilter implementation, so it will scan the whole content of the target folder, and returning only the names of the files that match your constraint:

 public void onClick(View v) {

         File root = Environment.getExternalStorageDirectory();
         File saveFolder= new File(root, "Save");

         String[] files=saveFolder.list(
            new FilenameFilter() {
                public boolean accept(File dir, String name) {
                //define here you filter condition for every single file
                    return name.startsWith("3_test");

                }
            });

         if(files.length>0) {
             System.out.println("FOUND!");
         } else {
             System.out.println("NOT FOUND!");
         }
     }