FileVisitor以打印给定目录上具有给定扩展名的文件数。

import java.io.IOException;

import java.nio.file.*;
/**
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**/

import java.nio.file.attribute.BasicFileAttributes;


/**

 * FileVisitor example which will print the

 * number of files with a given extension on a given directory.

 */

public class FileVisitorExample {

    public static void main(String[] args) throws IOException {

        MyFileChecker mfc = new MyFileChecker();

        Files.walkFileTree(Paths.get("/home/macluq/tmp"), mfc);

        System.out.println(mfc.getCount());

    }

}
/*来自 
 时代Java公众号*/


class MyFileChecker extends SimpleFileVisitor<Path> {

    private final PathMatcher matcher;

    private static int count;


    public MyFileChecker(){

        matcher = FileSystems.getDefault().getPathMatcher("glob:*.java");

    }


    void check(Path p){

        Path name = p.getFileName();

        if(name != null && matcher.matches(name)){

            count++;

        }

    }


    public