io - Java - Moving files within filesystem -

i working on school assignment , doing simple filemanager should move files suffix "jpg" (for example) folder. problem should recursively through folders.

example: in folder "downloads":

--downloads ----me.jpg ----smth.doc ----folder1 ------you.jpg 

and have move .jpg files folder "photos" , create "folder1" there , move file "you.jpg"

this have seems move files "downloads folder"

private void move(string suffix, string sourcepath, string destination) throws ioexception{     file dir = new file(sourcepath);     file destdir = new file(destination);     string src;     string dst;      (file f : dir.listfiles(new extensionfilter(suffix))){         string name = f.getname();         src = f.getabsolutepath();         dst = destination + "\\" + name;         files.createdirectories(paths.get(destination));         files.move(paths.get(src), paths.get(dst));         logs.add("mv;" + src + ";" + dst);     }      (file f : dir.listfiles(new directoryfilter())){         move(suffix, f.getpath(), destination + "\\" + f.getname());         } } 

logs arraylist save log files have been moved

this lot easier using java nio.2 api in combination java 8.

java 8 introduced method files.walk(path) returns stream of paths under given path, recursively:

return stream lazily populated path walking file tree rooted @ given starting file.

a proposed solution following:

private void move(string suffix, path source, path destination) throws ioexception {     files.createdirectories(destination);     files.walk(source)          .filter(p -> p.tostring().endswith(suffix))          .foreach(p -> {              path dest = destination.resolve(source.relativize(p));              try {                  files.createdirectories(dest.getparent());                  files.move(p, dest);              } catch (ioexception e) {                  throw new uncheckedioexception(e);              }          }); } 

this code creates destination path. walks starting source path , filters paths ends given suffix. finally, each of them:

• source.relativize(p) returns relative path source path.

  for example, on unix, if path "/a/b" , given path "/a/b/c/d" resulting relative path "c/d".

  as such, return part of path under source can copy target path.

• destination.resolve(other) returns path constructed appending path other path:

  in simplest case, [...], in case method joins given path path , returns resulting path ends given path.

• so now, have full target path. first need create parent directories files.createdirectories(dir). dest.getparent() returns parent path, say, drops filename path. final step moving source path target path files.move(source, target).

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if can't upgrade java 8 yet , keep java 7, can still use files.walkfiletree instead of files.walk (the rest of code need adjustment idea same).