A.不使用递归：
import java.io.File;
import java.util.LinkedList;
public class FileSystem {
public static void main(String[] args) {
long a = System.currentTimeMillis();
LinkedList list = new LinkedList();
File dir = new File("c:\\java\\");
File file[] = dir.listFiles();
for (int i = 0; i < file.length; i++) {
if (file[i].isDirectory()) list.add(file[i]);
else
System.out.println(file[i].getAbsolutePath());
}
File tmp; while (!list.isEmpty()) {
tmp = list.removeFirst();
if (tmp.isDirectory()) {
file = tmp.listFiles();
if (file == null) continue;
for (int i = 0; i < file.length; i++) {
if (file[i].isDirectory()) list.add(file[i]);
else
System.out.println(file[i].getAbsolutePath());
}
}
else
{ System.out.println(tmp.getAbsolutePath()); }
}
System.out.println(System.currentTimeMillis() - a);
}
}