#37 : alternate signature for async event handlers : public void foo(…

…AsyncResolution). AsyncResolution is no more a base class to extend but instead it's a param to the event handler that allows to complete() the async processing.

examples/src/main/java/net/sourceforge/stripes/examples/async/AsyncActionBean.java

@@ -43,81 +43,63 @@ public Resolution display() {
 	 * asynchronously fetch data from a remote web service (github)
 	 * and set instance fields for use in the view.
  	 */
-	public Resolution asyncEvent() {
-
-		// we return an AsyncResolution : this triggers the asynchronous servlet mode...
-		return new AsyncResolution() {
-
-			// only this method to implement. you must complete() or dispatch() yourself.
-			@Override
-			protected void executeAsync() throws Exception {
-
-				// we use an Async Http Client in order to call the github web service as a demo.
-				// the async http client calls on of the lambdas when he's done, and
-				// then we dispatch to a JSP, completing the async request.
-
-				HttpHost host = new HttpHost("api.github.com", 443, "https");
-				new AsyncHttpClient(host)
-					.buildRequest("/repos/StripesFramework/stripes/commits")
-					.completed(result -> {
-
-						// response is returned, deserialize result
-						status = result.getStatusLine().getStatusCode();
-						if (status == 200) {
-							ByteArrayOutputStream bos = new ByteArrayOutputStream();
-							try {
-								result.getEntity().writeTo(bos);
-								bos.close();
-								ghResponse = bos.toString("UTF-8");
-							} catch (Exception e) {
-								clientException = e;
-							}
-							dispatch(JSP_PATH);
-						} else {
-							ghResponse = result.getStatusLine().getReasonPhrase();
-							dispatch(JSP_PATH);
-						}
-
-					})
-					.failed(ex -> {
-
-						// http client failure
-						clientException = ex;
-						dispatch(JSP_PATH);
-
-					})
-					.cancelled(() -> {
-
-						// just for demo, we never call it...
-						cancelled = true;
-						dispatch(JSP_PATH);
-
-					})
-					.get(); // trigger async request
-			}
-		};
+	public void asyncEvent(AsyncResolution async) {
+
+		// we use an Async Http Client in order to call the github web service as a demo.
+		// the async http client calls back one of the lambdas when it's done, and
+		// then we complete the async request.
+
+		final Resolution forwardResolution = new ForwardResolution(JSP_PATH);
+		HttpHost host = new HttpHost("api.github.com", 443, "https");
+		new AsyncHttpClient(host)
+			.buildRequest("/repos/StripesFramework/stripes/commits")
+			.completed(result -> {
+
+				// response is returned, deserialize result
+				status = result.getStatusLine().getStatusCode();
+				if (status == 200) {
+					ByteArrayOutputStream bos = new ByteArrayOutputStream();
+					try {
+						result.getEntity().writeTo(bos);
+						bos.close();
+						ghResponse = bos.toString("UTF-8");
+					} catch (Exception e) {
+						clientException = e;
+					}
+					async.complete(forwardResolution);
+				} else {
+					ghResponse = result.getStatusLine().getReasonPhrase();
+					async.complete(forwardResolution);
+				}
+
+			})
+			.failed(ex -> {
+
+				// http client failure
+				clientException = ex;
+				async.complete(forwardResolution);
+
+			})
+			.cancelled(() -> {
+
+				// just for demo, we never call it...
+				cancelled = true;
+				async.complete(forwardResolution);
+
+			})
+			.get(); // trigger async request
 	}
 
 	@DontValidate
-	public Resolution asyncEventThatTimeouts() {
-		return new AsyncResolution() {
-			@Override
-			protected void executeAsync() throws Exception {
-				getAsyncContext().setTimeout(1000);
-				getResponse().getWriter().write("OK");
-				// never call complete/dispatch...
-			}
-		};
+	public void asyncEventThatTimeouts(AsyncResolution r) throws Exception {
+		r.getAsyncContext().setTimeout(1000);
+		r.getResponse().getWriter().write("OK");
+		// never call complete/dispatch...
 	}
 
 	@DontValidate
-	public Resolution asyncEventThatThrows() {
-		return new AsyncResolution() {
-			@Override
-			protected void executeAsync() throws Exception {
-				throw new RuntimeException("WTF");
-			}
-		};
+	public void asyncEventThatThrows(AsyncResolution r) {
+		throw new RuntimeException("BOOM");
 	}
 
 	// getters for instance fields that have been set by event method

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

@@ -3,13 +3,23 @@
 import javax.servlet.AsyncContext;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-import java.util.function.Consumer;
-import java.util.function.Supplier;
+import java.lang.reflect.Method;
 
-public abstract class AsyncResolution implements Resolution {
+public class AsyncResolution implements Resolution {
 
+	private final HttpServletRequest request;
+	private final HttpServletResponse response;
+	private final Object bean;
+	private final Method handler;
 	private AsyncContext asyncContext;
 
+	public AsyncResolution(HttpServletRequest request, HttpServletResponse response, Object bean, Method handler) {
+		this.request = request;
+		this.response = response;
+		this.bean = bean;
+		this.handler = handler;
+	}
+
 	public AsyncContext getAsyncContext() {
 		return asyncContext;
 	}
@@ -28,8 +38,6 @@ public void setContext(ActionBeanContext context) {
 		this.context = context;
 	}
 
-	private HttpServletRequest request;
-	private HttpServletResponse response;
 
 	public HttpServletRequest getRequest() {
 		return request;
@@ -40,29 +48,25 @@ public HttpServletResponse getResponse() {
 	}
 
 	@Override
-	public final void execute(HttpServletRequest request, HttpServletResponse response) throws Exception {
-		this.request = request;
-		this.response = response;
-		executeAsync();
+	public void execute(HttpServletRequest request, HttpServletResponse response) throws Exception {
+		// invoke the handler (start async has been done already) and let it complete...
+		handler.invoke(bean, this);
 	}
 
-	protected abstract void executeAsync() throws Exception;
-
-	protected void dispatch(String path) {
+	public void dispatch(String path) {
 		getAsyncContext().dispatch(path);
 	}
 
-	protected void complete() {
+	public void complete() {
 		getAsyncContext().complete();
 	}
 
-	protected void complete(Resolution resolution) {
+	public void complete(Resolution resolution) {
 		try {
 			resolution.execute(getRequest(), getResponse());
 		} catch (Exception e) {
 			throw new RuntimeException(e);
 		}
 	}
 
-
 }

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

@@ -15,11 +15,8 @@
 package net.sourceforge.stripes.controller;
 
 import java.lang.annotation.Annotation;
-import net.sourceforge.stripes.action.ActionBean;
-import net.sourceforge.stripes.action.ActionBeanContext;
-import net.sourceforge.stripes.action.DontBind;
-import net.sourceforge.stripes.action.DontValidate;
-import net.sourceforge.stripes.action.Resolution;
+
+import net.sourceforge.stripes.action.*;
 import net.sourceforge.stripes.config.Configuration;
 import net.sourceforge.stripes.exception.StripesServletException;
 import net.sourceforge.stripes.util.HtmlUtil;
@@ -49,15 +46,6 @@
 import java.util.TreeSet;
 import java.util.WeakHashMap;
 import javax.servlet.http.HttpServletResponse;
-import net.sourceforge.stripes.action.DELETE;
-import net.sourceforge.stripes.action.ErrorResolution;
-import net.sourceforge.stripes.action.GET;
-import net.sourceforge.stripes.action.HEAD;
-import net.sourceforge.stripes.action.HttpRequestMethod;
-import net.sourceforge.stripes.action.JsonBuilder;
-import net.sourceforge.stripes.action.POST;
-import net.sourceforge.stripes.action.PUT;
-import net.sourceforge.stripes.action.RestActionBean;
 
 /**
  * Helper class that contains much of the logic used when dispatching requests
@@ -657,7 +645,17 @@ public Resolution intercept(ExecutionContext ctx) throws Exception {
                 // a exception to be handled differently for RestActionBeans that regular
                 // ActionBeans, they will need to write this code accordingly in their
                 // ExceptionHandler class.
-                Object returnValue = handler.invoke(bean);
+                final Object returnValue;
+                if (NameBasedActionResolver.isAsyncEventHandler(handler)) {
+                    returnValue = new AsyncResolution(
+                        ctx.getActionBeanContext().getRequest(),
+                        ctx.getActionBeanContext().getResponse(),
+                        bean,
+                        handler
+                    );
+                } else {
+                    returnValue = handler.invoke(bean);
+                }
 
                 fillInValidationErrors(ctx);
 

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

@@ -186,6 +186,9 @@ protected void service(final HttpServletRequest request, final HttpServletRespon
                     // start async processing
                     log.debug("Starting async processing from action ", ctx.getActionBean());
                     AsyncContext asyncContext = request.startAsync(request, response);
+                    AsyncResolution asyncResolution = (AsyncResolution)resolution;
+                    asyncResolution.setAsyncContext(asyncContext);
+                    asyncResolution.setContext(ctx.getActionBeanContext());
                     final PageContext pc = pageContext;
                     // register listener for finalizing the async processing
                     asyncContext.addListener(new AsyncListener() {
@@ -237,9 +240,6 @@ public void onStartAsync(AsyncEvent event) throws IOException {
                                 "response=", event.getSuppliedResponse());
                         }
                     });
-                    AsyncResolution asyncResolution = (AsyncResolution)resolution;
-                    asyncResolution.setAsyncContext(asyncContext);
-                    asyncResolution.setContext(ctx.getActionBeanContext());
                 }
                 executeResolution(ctx, resolution);
             }

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

@@ -14,10 +14,7 @@
  */
 package net.sourceforge.stripes.controller;
 
-import net.sourceforge.stripes.action.ActionBean;
-import net.sourceforge.stripes.action.ActionBeanContext;
-import net.sourceforge.stripes.action.Resolution;
-import net.sourceforge.stripes.action.ForwardResolution;
+import net.sourceforge.stripes.action.*;
 import net.sourceforge.stripes.config.Configuration;
 import net.sourceforge.stripes.exception.StripesServletException;
 import net.sourceforge.stripes.util.Literal;
@@ -26,6 +23,7 @@
 import javax.servlet.ServletContext;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
+import java.lang.reflect.Parameter;
 import java.net.MalformedURLException;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -243,9 +241,24 @@ public String getHandledEvent(Method handler) {
             name = handler.getName();
         }
 
+        if (name == null && isAsyncEventHandler(handler)) {
+            name = handler.getName();
+        }
+
         return name;
     }
 
+    public static boolean isAsyncEventHandler(Method handler) {
+        if (!Modifier.isAbstract(handler.getModifiers())
+            && handler.getReturnType().equals(Void.TYPE)
+            && handler.getParameterCount() == 1) {
+            // look at arg type
+            Parameter p = handler.getParameters()[0];
+            return AsyncResolution.class.isAssignableFrom(p.getType());
+        }
+        return false;
+    }
+
     /**
      * <p>Overridden to trap the exception that is thrown when a URL cannot be mapped to an
      * ActionBean and then attempt to construct a dummy ActionBean that will forward the