压缩JS，提高代码执行速度

import java.io.BufferedReader;
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.InputStreamReader;


public class ZipJS {
	public static void main(String[] args) throws Exception {
		//文件存在目录
		String dir = "D:\\js";  
		String[] fileNames = getFileNames(dir); 
		System.out.println("The total number of files:"+fileNames.length);
		for (String string : fileNames) {
			if(string.equals("yuicompressor-2.4.jar")){ 	   
				continue ;
			}
			String cmd = "java -jar yuicompressor-2.4.jar --type js "+string+" -o "+string+" --charset utf-8"; 
			//String cmd = "java -jar yuicompressor-2.4.jar --type css "+string+" -o "+string+" --charset utf-8"; 
			Runtime.getRuntime().exec("cmd /c D: & cd "+dir+" & "+cmd);  
		}
	}
	
	//获取当前文件夹下所有文件名称
	private static String[] getFileNames(String dir) {
		File file = new File(dir);
		File[] files = file.listFiles(new FileOnlyFilter());
		String[] ary = new String[files.length];
		for (int i = 0; i < files.length; i++) {
			ary[i] = files[i].getName();
		}
		return ary ;
	}
}

class FileOnlyFilter implements FileFilter {
	 public boolean accept(File file) {
		 return file.isFile();
	 }
}