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Java遍历文件夹的2种方法


 

   

  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);

  }

  }

  B.使用递归:

  import java.io.File;

  import java.util.ArrayList;

  public class FileSystem1 {

  private static ArrayList filelist = new ArrayList();

  public static void main(String[] args) {

  long a = System.currentTimeMillis();

  refreshFileList("c:\java");

  System.out.println(System.currentTimeMillis() - a);

  }

  public static void refreshFileList(String strPath) {

  File dir = new File(strPath);

  File[] files = dir.listFiles();

  if (files == null)

  return;

  for (int i = 0; i < files.length; i++) {

  if (files[i].isDirectory()) {

  refreshFileList(files[i].getAbsolutePath());

  } else {

  String strFileName = files[i].getAbsolutePath().toLowerCase();

  System.out.println("---"+strFileName);

  filelist.add(files[i].getAbsolutePath());

  }

  }

  }

  }

  结论:经过测试,使用递归的方法B性能相对好一些。