java操作文件夹，列出文件夹下的所有文件名 - JAVA

import java.io.File;
public class FileNameOp {

public static int n=0;
public static void fun(File file,String ext){
File f[]=file.listFiles();
if (f != null){
for (int i=0;i fun(f[i],ext);
}
}else{
String filename = file.getName();
if(filename.length()>ext.length()){
filename = filename.substring(filename.length()-ext.length());

if(filename.equals(ext)){
n++;
System.out.println(file.getName());
}
}
}
}

public static void main(String args[]){
File javaFile=new File("F:\\workspace");
fun(javaFile,".java");
System.out.println("----------共"+n+"个文件");
}
}