Replace special characters of File and Folder names with new ones.

Renamer.java

import java.io.File;


public class Renamer {
	private boolean dryRun = true;
	private String in = "&";
	private String out = "-";
	private File root;
	
	private void init(String[] args){
		String rootFolder = args[0];
		root = new File(rootFolder);
		if(!root.exists()){
			System.out.println("Root-Folder "+rootFolder+" doesn't exists.");
		}
		if(args.length == 2){
			dryRun = (args[1].equalsIgnoreCase("process") ? true : false);
		}
	}
	
	public void run(){
		File newRoot = rename(root);
		iterate(newRoot);
	}
	
	private void iterate(File folder){
		File[] files = folder.listFiles();
		for(File file : files){
			if(file.isDirectory()){
				File renamed = rename(file);
				iterate(renamed);
			}else if(file.isFile()){
				rename(file);
			}
		}
	}
	
	private File rename(File file){
		String name = file.getName();
		String newName = name.replace(in, out);
		
		if(name.equals(newName)){
			//no replacing needed
			return file;
		}
		
		File newFile = new File(file.getParent()+File.separator+newName);
		if(dryRun){
			System.out.println("[DRYRUN] Renaming from "+file.getAbsolutePath()+" to "+newFile.getAbsolutePath());
			return file;
		}
		
		if(newFile.exists()){
			System.out.println(file.getAbsolutePath()+" can't be renamed to "+newFile.getAbsolutePath()+" because new Path already exists.");
			return file;
		}
		
		boolean renamed = file.renameTo(newFile);
		if(!renamed){
			System.out.println(file.getAbsolutePath()+" can't be renamed to "+newFile.getAbsolutePath()+". Cause is unknown. Maybe locked?");
			return file;
		}
		
		return newFile;
	}
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		if(args == null || args.length == 0){
			System.out.println("Please pass the Root-Folder.");
			System.exit(0);
		}
		Renamer renamer = new Renamer();
		renamer.init(args);
		renamer.run();
	}

}