如何显示目录中的所有文件？（How to display all the files in a directory?）

问题描述 (Problem Description)

如何显示目录中的所有文件？

解决方案 (Solution)

下面的示例演示如何使用File类的list方法显示目录中包含的所有文件。

import java.io.*;
public class Main {
   public static void main(String[] args) {
      File dir = new File("C:");
      String[] children = dir.list();
      if (children == null) {
         System.out.println( "Either dir does not exist or is not a directory");
      } else { 
         for (int i=0; i< children.length; i++) {
            String filename = children[i];
            System.out.println(filename);
         }
      }
   }
}

结果 (Result)

上面的代码示例将产生以下结果。

build
build.xml
destnfile
detnfile
filename
manifest.mf
nbproject
outfilename
src
srcfile
test

以下是显示目录中所有文件的另一个示例。

import java.io.File;
public class ReadFiles { 
   public static File folder = new File("C:\\Apache24\\htdocs");
   static String temp = "";
   public static void main(String[] args) {
      System.out.println("Reading files under the folder "+ folder.getAbsolutePath());
      listFilesForFolder(folder);
   } 
   public static void listFilesForFolder(final File folder) {
      for (final File fileEntry : folder.listFiles()) {
         if (fileEntry.isDirectory()) {
            listFilesForFolder(fileEntry);
         } else {
            if (fileEntry.isFile()) {
               temp = fileEntry.getName();
               if ((temp.substring(temp.lastIndexOf('.') 
                  + 1, temp.length()).toLowerCase()).equals("txt"))System.out.println(
                  "File= " + folder.getAbsolutePath()+ "\\" + fileEntry.getName());
            } 
         } 
      } 
   }
}

上面的代码示例将产生以下结果。

Reading files under the folder C:\Apache24\htdocs
File= C:\Apache24\htdocs\android\bkp\end.txt
File= C:\Apache24\htdocs\android\end.txt
File= C:\Apache24\htdocs\cpp_standard_library\images\code.txt
File= C:\Apache24\htdocs\java\Java - Data Structures.txt
File= C:\Apache24\htdocs\java\Java - Inheritance.txt
File= C:\Apache24\htdocs\scripts\easyui\changelog.txt