#37 : cleanup, cache Async implementation class ctor to avoid looking…

… it up too often

stripes/src/main/java/net/sourceforge/stripes/controller/AsyncResolution.java

@@ -2,6 +2,8 @@
 
 import net.sourceforge.stripes.action.ActionBean;
 import net.sourceforge.stripes.action.Resolution;
+import net.sourceforge.stripes.exception.StripesRuntimeException;
+import net.sourceforge.stripes.util.Log;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -11,12 +13,36 @@
 
 public abstract class AsyncResolution implements Resolution {
 
+ private static final Log log = Log.getInstance(AsyncResolution.class);
+
  private static final String REQ_ATTR_NAME = "__Stripes_Async_Resolution";
  private final HttpServletRequest request;
  private final HttpServletResponse response;
  private final ActionBean bean;
  private final Method handler;
 
+ private static Constructor<?> ctor = null;
+
+ static {
+ try {
+ HttpServletRequest.class.getMethod("startAsync");
+ Class<?> impl = Class.forName("net.sourceforge.stripes.controller.AsyncResolutionServlet3");
+ ctor = impl.getDeclaredConstructor(
+ HttpServletRequest.class,
+ HttpServletResponse.class,
+ ActionBean.class,
+ Method.class);
+ } catch (NoSuchMethodException e) {
+ // servlet3 not available
+ log.info("Container is not using Servlet3 : Async event handlers will throw runtime exceptions.");
+ } catch (Exception e) {
+ // should not happen unless we break internals (bad refactor etc).
+ log.error("Exception while initializing AsyncResolution implementation class.", e);
+ throw new RuntimeException(e);
+ }
+
+ }
+
  private Runnable cleanupCallback;
  private long timeout;
 
@@ -67,23 +93,12 @@ public void execute(HttpServletRequest request, HttpServletResponse response) th
  public abstract void setTimeout(long timeout);
 
  public static AsyncResolution newInstance(HttpServletRequest request, HttpServletResponse response, ActionBean bean, Method handler) {
- // check wether or not we're using servlet3
+ if (ctor == null) {
+ throw new StripesRuntimeException("Async events are not available in your container (requires Servlet3+).");
+ }
  try {
- HttpServletRequest.class.getMethod("startAsync");
- Class<?> impl = Class.forName("net.sourceforge.stripes.controller.AsyncResolutionServlet3");
- Constructor<?> ctor = impl.getDeclaredConstructor(
- HttpServletRequest.class,
- HttpServletResponse.class,
- ActionBean.class,
- Method.class);
  Object o = ctor.newInstance(request, response, bean, handler);
  return (AsyncResolution)o;
- } catch (NoSuchMethodException e) {
- // not using servlet 3, throw exception for the moment
- throw new UnsupportedOperationException("Async action beans require Servlet3+");
- } catch (ClassNotFoundException e) {
- // should never happen unless bad refactor
- throw new RuntimeException(e);
  } catch (IllegalAccessException e) {
  throw new RuntimeException(e);
  } catch (InstantiationException e) {

stripes/src/main/java/net/sourceforge/stripes/controller/DispatcherServlet.java

@@ -44,7 +44,6 @@
  *
  * @author Tim Fennell
  */
-//@WebServlet(asyncSupported = true)
 public class DispatcherServlet extends HttpServlet {
  private static final long serialVersionUID = 1L;