rename a directory at particular depth

package com.so.practice;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.apache.commons.io.FileUtils;

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

		String matchword = "POPCORN.";//PA__OPCON.MES.

		List<File> files = getDirs(new File(path), 0); //level 0 is inside parent , level 1, and so on
		System.out.println(files);
		String[] paths = new String[files.size()];

		int i = 0;
		for (File file : files) {
			paths[i++] = file.getAbsolutePath();
		}
		

		//File  f = null;
		HashMap<String, String > old_new = new HashMap<>();
		for (int j = 0; j < paths.length; j++) {
			System.out.println(paths[j]);
			String old_path = paths[j];
				
			if(old_path.contains(matchword)){
			
			paths[j] =paths[j].replaceAll(matchword, ""); /*replace with desired rename*/

			old_new.put(old_path, paths[j]);
			
			}else{
				System.out.println("skipping->"+old_path);
			}
			//f = new File(paths[j]);
			//f.mkdirs();
		}

		for(String key : old_new.keySet()){
			//FileUtils.copyDirectory(new File(key), new File(old_new.get(key)));
			moveDirectory(new File(key), new File(old_new.get(key)));

		}


		//FileUtils.copyDirectory(new File(old_new.get), new File(arg0));

	}
	static List<File> getDirs(File parent, int level){
		List<File> dirs = new ArrayList<File>(); //to store 
		for(File f: parent.listFiles()){
			if(f.isDirectory()) {
				if (level==0) dirs.add(f);
				else 
					if (level > 0) dirs.addAll(getDirs(f,level-1)); //recursion
			}
		}
		return dirs;
	}
	public static void moveDirectory(File srcDir, File destDir) throws IOException {
		if (srcDir == null) {
			throw new NullPointerException("Source must not be null");
		}
		if (destDir == null) {
			throw new NullPointerException("Destination must not be null");
		}
		if (!srcDir.exists()) {
			throw new FileNotFoundException("Source '" + srcDir + "' does not exist");
		}
		if (!srcDir.isDirectory()) {
			throw new IOException("Source '" + srcDir + "' is not a directory");
		}
		boolean rename = srcDir.renameTo(destDir);
		if (!rename) {
			if (destDir.getCanonicalPath().startsWith(srcDir.getCanonicalPath())) {
				throw new IOException("Cannot move directory: "+srcDir+" to a subdirectory of itself: "+destDir);
			}
			FileUtils.copyDirectory( srcDir, destDir );
			FileUtils.deleteDirectory( srcDir );
			if (srcDir.exists()) {
				throw new IOException("Failed to delete original directory '" + srcDir +
						"' after copy to '" + destDir + "'");
			}
		}
	}
}

rename or move a directory

package com.so.practice;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;

import org.apache.commons.io.FileUtils;

public class moveDirectoryinproj {

	public static void main(String[] args) throws IOException {
		
		File src  = new File("D:\\root\\choc");
		File dest  = new File("D:\\root\\candy");
		moveDirectory(src, dest);
	}
	public static void moveDirectory(File srcDir, File destDir) throws IOException {
		if (srcDir == null) {
			throw new NullPointerException("Source must not be null");
		}
		if (destDir == null) {
			throw new NullPointerException("Destination must not be null");
		}
		if (!srcDir.exists()) {
			throw new FileNotFoundException("Source '" + srcDir + "' does not exist");
		}
		if (!srcDir.isDirectory()) {
			throw new IOException("Source '" + srcDir + "' is not a directory");
		}
		boolean rename = srcDir.renameTo(destDir);
		if (!rename) {
			if (destDir.getCanonicalPath().startsWith(srcDir.getCanonicalPath())) {
				throw new IOException("Cannot move directory: "+srcDir+" to a subdirectory of itself: "+destDir);
			}
			FileUtils.copyDirectory( srcDir, destDir );
			FileUtils.deleteDirectory( srcDir );
			if (srcDir.exists()) {
				throw new IOException("Failed to delete original directory '" + srcDir +
						"' after copy to '" + destDir + "'");
			}
		}
	}
}