private static int einzug = 0;
static void list(String dirName){
einzug += 1;
File dir = new File(dirName);
String[] names = dir.list();
for(int i = 0; i < names.length; i++){
for(int j = 1; j < einzug; j++)
System.out.print(" ");
System.out.println(names[i]);
File unterFile = new File(dir.getAbsolutePath(), names[i]);
if (unterFile.isDirectory()){
list(unterFile.getAbsolutePath());
}
}
einzug -= 1;
}
public static void main(String[] args) {
list("D:\\data");
}