java 检测目录下的文件

java.io.File class contains two methods using which we can find out if the file is a directory or a regular file in java.

java.io.File类包含两个方法，通过它们我们可以确定文件是java中的目录还是常规文件。

1. isFile(): This method returns true if file exists and is a regular file, note that if file doesn’t exist then it returns false.isFile() ：如果文件存在并且是常规文件，则此方法返回true，请注意，如果文件不存在，则返回false。
2. isDirectory(): This method returns true if file is actually a directory, if path doesn’t exist then it returns false.isDirectory() ：如果文件实际上是目录，则此方法返回true；如果路径不存在，则返回false。

While checking if a file is a directory or regular file, we should first check if the file exists or not. If it exists then only we should check if it’s a directory or file.

在检查文件是目录文件还是常规文件时，我们应该首先检查文件是否存在。 如果存在，那么只有我们应该检查它是目录还是文件。

A simple java program showing it’s usage.

一个显示其用法的简单Java程序。

package com.journaldev.files;import java.io.File;public class CheckDirectoryOrFile {public static void main(String[] args) {File file = new File("/Users/pankaj/source.txt");File dir = new File("/Users/pankaj");File notExists = new File("/Users/pankaj/notafile");System.out.println("/Users/pankaj/source.txt is file?"+file.isFile());System.out.println("/Users/pankaj/source.txt is directory?"+file.isDirectory());System.out.println("/Users/pankaj is file?"+dir.isFile());System.out.println("/Users/pankaj is directory?"+dir.isDirectory());System.out.println("/Users/pankaj/notafile is file?"+notExists.isFile());System.out.println("/Users/pankaj/notafile is directory?"+notExists.isDirectory());}}

Output of the above program is:

上面程序的输出是：

/Users/pankaj/source.txt is file?true
/Users/pankaj/source.txt is directory?false
/Users/pankaj is file?false
/Users/pankaj is directory?true
/Users/pankaj/notafile is file?false
/Users/pankaj/notafile is directory?false

翻译自: https://www.journaldev.com/909/check-file-directory-file-java

java 检测目录下的文件