import sun.jvm.hotspot.tools.jcore.ClassDump; //导入依赖的package包/类
public void doit(Tokens t) {
    int tcount = t.countTokens();
    if (tcount > 2) {
        usage();
        return;
    }
    try {
       String prefix = "";
       String option = "all"; // default
       switch(tcount) {
           case 0:
               break;
           case 1:
               option = t.nextToken();
               if (!option.equalsIgnoreCase("all") && !option.equalsIgnoreCase("app") &&
                   !option.equalsIgnoreCase("root")) {
                  prefix = option;
                  option = "all";
               }
               break;
           case 2:
               option = t.nextToken();
               prefix = t.nextToken();
               break;
           default:
               usage();
               return;
       }
       if (!option.equalsIgnoreCase("all") && !option.equalsIgnoreCase("app") &&
                   !option.equalsIgnoreCase("boot")) {
           usage();
           return;
       }
       ClassDump cd = new ClassDump();
       if (option.equalsIgnoreCase("all") || option.equalsIgnoreCase("boot")) {
         cd.setClassFilter(new BootFilter());
         cd.setJarOutput(prefix + "boot.jar");
         cd.run();
       }
       if (option.equalsIgnoreCase("all") || option.equalsIgnoreCase("app")) {
         cd.setClassFilter(new NonBootFilter());
         cd.setJarOutput(prefix + "app.jar");
         cd.run();
       }
    } catch (IOException ioe) {
       ioe.printStackTrace();
    }
}