I have a string that uses parts of another String, how to make this code "cleaner"? Since it is very difficult to understand.
String sessionHash = dirPath.substring(dirPath.substring(0, dirPath.length() - 1).lastIndexOf("/"));
sessionHash: / 23980dc32e16792007de3343f1f99211 /
dirPath: / home / daniela / oknok / data / uploads / 23980dc32e16792007de3343f1f99211 /
So I understand the method getname() produces the result you expect:
String sessionHash = new File(dirPath).getName();
Or to stay the same:
String sessionHash = "/" + new File(dirPath).getName() + "/";
See working on ideone .
You can do this through the split ": it breaks a string into pieces using a regular expression as a delimiter. Breaking around the bar, and taking the penultimate piece (the last one is empty, since it is after the last bar) you get the result you want:
String[] partes = dirPath.split("/");
String sessionHash = "/" + partes[partes.length-2] + "/";
In the specific case of the slash, however, it is simpler to use the File class, such as suggested by bigown .