Java使用递归检索文件个数

 使用到了Java.io中的File类

File类常见方法：

1.boolen exists()

2.String getName()

3.boolean isDirectory()

4.boolean isFile()

5.File[] listFiles()

import java.io.*;

/*
打印某个目录下所有文件和目录的名字
 */
public class FileDisplay {
    public static void main(String[] args) throws Exception{
        FileDisplay fd=new FileDisplay();
        String dirName="G:\Users\14616\Pictures\古墓丽影";
        int count=fd.printDir(dirName);
        System.out.println("文件数"+count);
    }


    public int printDir(String dirName){
        int fileCount=0;
        File dirFile=new File(dirName);
        File[] subFile=dirFile.listFiles();
        System.out.println("fileLength"+subFile.length);
        if(subFile==null||subFile.length==0)
            return 0;

        for(int i=0;i<subFile.length;i++){
            if(subFile[i].isDirectory()){
                String subDir=subFile[i].getAbsolutePath();
                System.out.println("目录"+subDir);

                fileCount+=printDir(subDir);
            }

            if(subFile[i].isFile()){
                fileCount++;
                String fileName=subFile[i].getAbsolutePath();
                System.out.println("文件"+fileName);
            }
        }
        return fileCount;
    }
}

输出

"G:Program FilesJavajdk1.8.0_121injava" "-javaagent:G:JetBrainsIntelliJ IDEA 2017.1.4libidea_rt.jar=58448:G:JetBrainsIntelliJ IDEA 2017.1.4in" -Dfile.encoding=UTF-8 -classpath "G:Program FilesJavajdk1.8.0_121jrelibcharsets.jar;G:Program FilesJavajdk1.8.0_121jrelibdeploy.jar;G:Program FilesJavajdk1.8.0_121jrelibextaccess-bridge-64.jar;G:Program FilesJavajdk1.8.0_121jrelibextcldrdata.jar;G:Program FilesJavajdk1.8.0_121jrelibextdnsns.jar;G:Program FilesJavajdk1.8.0_121jrelibextjaccess.jar;G:Program FilesJavajdk1.8.0_121jrelibextjfxrt.jar;G:Program FilesJavajdk1.8.0_121jrelibextlocaledata.jar;G:Program FilesJavajdk1.8.0_121jrelibext
ashorn.jar;G:Program FilesJavajdk1.8.0_121jrelibextsunec.jar;G:Program FilesJavajdk1.8.0_121jrelibextsunjce_provider.jar;G:Program FilesJavajdk1.8.0_121jrelibextsunmscapi.jar;G:Program FilesJavajdk1.8.0_121jrelibextsunpkcs11.jar;G:Program FilesJavajdk1.8.0_121jrelibextzipfs.jar;G:Program FilesJavajdk1.8.0_121jrelibjavaws.jar;G:Program FilesJavajdk1.8.0_121jrelibjce.jar;G:Program FilesJavajdk1.8.0_121jrelibjfr.jar;G:Program FilesJavajdk1.8.0_121jrelibjfxswt.jar;G:Program FilesJavajdk1.8.0_121jrelibjsse.jar;G:Program FilesJavajdk1.8.0_121jrelibmanagement-agent.jar;G:Program FilesJavajdk1.8.0_121jrelibplugin.jar;G:Program FilesJavajdk1.8.0_121jrelib
esources.jar;G:Program FilesJavajdk1.8.0_121jrelib
t.jar;H:practiceoutproductionpractice" FileDisplay
fileLength8
文件G:Users14616Pictures古墓丽影image_rise_of_the_tomb_raider-27559-2982_0010.jpg
文件G:Users14616Pictures古墓丽影image_rise_of_the_tomb_raider-27559-2982_0011.jpg
文件G:Users14616Pictures古墓丽影image_rise_of_the_tomb_raider-27559-2982_0012.jpg
文件G:Users14616Pictures古墓丽影image_rise_of_the_tomb_raider-28633-2982_0001.jpg
文件G:Users14616Pictures古墓丽影image_rise_of_the_tomb_raider-29110-2982_0001.jpg
文件G:Users14616Pictures古墓丽影image_rise_of_the_tomb_raider-29110-2982_0002.jpg
目录G:Users14616Pictures古墓丽影新建文件夹
fileLength5
文件G:Users14616Pictures古墓丽影新建文件夹image_rise_of_the_tomb_raider-25298-2982_0001.jpg
文件G:Users14616Pictures古墓丽影新建文件夹image_rise_of_the_tomb_raider-25298-2982_0002.jpg
文件G:Users14616Pictures古墓丽影新建文件夹image_rise_of_the_tomb_raider-25298-2982_0003.jpg
文件G:Users14616Pictures古墓丽影新建文件夹image_rise_of_the_tomb_raider-27559-2982_0001.jpg
文件G:Users14616Pictures古墓丽影新建文件夹image_rise_of_the_tomb_raider-27559-2982_0007.jpg
目录G:Users14616Pictures古墓丽影新建文件夹 (2)
fileLength9
文件G:Users14616Pictures古墓丽影新建文件夹 (2)image_rise_of_the_tomb_raider-29110-2982_0003.jpg
文件G:Users14616Pictures古墓丽影新建文件夹 (2)image_rise_of_the_tomb_raider-29110-2982_0006.jpg
文件G:Users14616Pictures古墓丽影新建文件夹 (2)image_rise_of_the_tomb_raider-30524-2982_0003.jpg
文件G:Users14616Pictures古墓丽影新建文件夹 (2)image_rise_of_the_tomb_raider-30659-2982_0005.jpg
文件G:Users14616Pictures古墓丽影新建文件夹 (2)image_rise_of_the_tomb_raider-30659-2982_0006.jpg
文件G:Users14616Pictures古墓丽影新建文件夹 (2)image_rise_of_the_tomb_raider-30659-2982_0010.jpg
文件G:Users14616Pictures古墓丽影新建文件夹 (2)image_rise_of_the_tomb_raider-30659-2982_0011.jpg
文件G:Users14616Pictures古墓丽影新建文件夹 (2)image_rise_of_the_tomb_raider-30659-2982_0016.jpg
文件G:Users14616Pictures古墓丽影新建文件夹 (2)image_rise_of_the_tomb_raider-30659-2982_0017.jpg
文件数20

需要注意的是：

listFiles方法返回的对象数组的长度是当前目录下文件和子目录的总数，而不是总文件的个数。