问java.uitl.zip.ZipFile如何在java中缓存文件

EN

public class Sample
{
    public static void main(String[] args) throws ZipException, IOException
    {
        long st = System.currentTimeMillis();
        File dir = new File("C:/temp/packages");
        File[] files = dir.listFiles();
        for(File file : files) {
            ZipFile zfile = new ZipFile(file);
        }
        long et = System.currentTimeMillis();
        System.out.println(et - st);
    }
}