一、walkFileTree方法遍历文件夹下jar包的数量

• 示例代码

package com.example.nettytest.nio.day2;
import java.io.IOException;
import java.nio.file.*;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.concurrent.atomic.AtomicInteger;
/**
 * @description:
 * @author: xz
 * @create: 2022-07-31 10:48
 */
public class TestWalkFileTree {
    public static void main(String[] args) throws IOException {
        foreachJar();
    }
     /**
     * 遍历文件夹下jar包的数量
     * */
    private static void foreachJar() throws IOException {
        //计数器:jar包数量
        AtomicInteger jarCount = new AtomicInteger();
        //walkFileTree遍历文件树
        Files.walkFileTree(Paths.get("D:\\Java\\jdk1.8.0_161"),new SimpleFileVisitor<Path>(){
            //重写遍历文件方法
            @Override
            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
                if(file.toString().endsWith(".jar")){
                    System.out.println(file);
                    jarCount.incrementAndGet();
                }
                return super.visitFile(file, attrs);
            }
        });
        System.out.println("jar count:" +jarCount);
    }
}

• 输出结果如下：