Support no-arg HandlerMethod and new beforeExecute #150

Call beforeExecute for no-arg HandlerMethod during preHandle and refactor advice dispatch. preHandle now throws Exception and detects HandlerMethod instances (Java pattern matching); when a handler method has no parameters it invokes beforeExecute immediately. Extracted a new beforeExecute(NativeWebRequest, HandlerMethod, Object...) to centralize invoking HandlerMethodAdvice.beforeExecuteMethod for all advices, and refactored the parameter-level beforeExecute to resolve arguments and delegate to the new method. Added ArrayUtils.isEmpty import and updated the test to declare throws Exception to match the changed signature.

Author: mercyblitz

microsphere-spring-webmvc/src/main/java/io/microsphere/spring/webmvc/method/support/InterceptingHandlerMethodProcessor.java

@@ -52,6 +52,7 @@
 import static io.microsphere.logging.LoggerFactory.getLogger;
 import static io.microsphere.spring.beans.BeanUtils.getSortedBeans;
 import static io.microsphere.spring.web.util.RequestAttributesUtils.getHandlerMethodArguments;
+import static io.microsphere.util.ArrayUtils.isEmpty;
 
 /**
  * The {@link HandlerMethod} processor that callbacks {@link HandlerMethodAdvice} based on
@@ -166,7 +167,13 @@ public void handleReturnValue(@Nullable Object returnValue, MethodParameter retu
     }
 
     @Override
-    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
+    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
+        if (handler instanceof HandlerMethod handlerMethod) {
+            MethodParameter[] methodParameters = handlerMethod.getMethodParameters();
+            if (isEmpty(methodParameters)) { // No-arg Handler Method
+                beforeExecute(new ServletWebRequest(request), handlerMethod);
+            }
+        }
         return true;
     }
 
@@ -300,16 +307,19 @@ private void afterResolveArgument(MethodParameter parameter, Object argument, Me
 
     private void beforeExecute(MethodParameter parameter, MethodParameterContext methodParameterContext,
                                NativeWebRequest webRequest, Object argument) throws Exception {
+        Object[] arguments = resolveArguments(webRequest, parameter, argument);
+        int parameterCount = methodParameterContext.parameterCount;
+        int parameterIndex = parameter.getParameterIndex();
+        if (parameterIndex == parameterCount - 1) {
+            HandlerMethod handlerMethod = methodParameterContext.method;
+            beforeExecute(webRequest, handlerMethod, arguments);
+        }
+    }
+
+    private void beforeExecute(NativeWebRequest webRequest, HandlerMethod handlerMethod, Object... arguments) throws Exception {
         for (int i = 0; i < handlerMethodAdvices.size(); i++) {
             HandlerMethodAdvice advice = handlerMethodAdvices.get(i);
-            int parameterCount = methodParameterContext.parameterCount;
-            Object[] arguments = resolveArguments(webRequest, parameter, argument);
-
-            int parameterIndex = parameter.getParameterIndex();
-            if (parameterIndex == parameterCount - 1) {
-                HandlerMethod handlerMethod = methodParameterContext.method;
-                advice.beforeExecuteMethod(handlerMethod, arguments, webRequest);
-            }
+            advice.beforeExecuteMethod(handlerMethod, arguments, webRequest);
         }
     }
 

microsphere-spring-webmvc/src/test/java/io/microsphere/spring/webmvc/method/support/InterceptingHandlerMethodProcessorTest.java

@@ -150,7 +150,7 @@ void testResolveArguments() {
     }
 
     @Test
-    void testPreHandle() {
+    void testPreHandle() throws Exception {
         assertTrue(this.processor.preHandle(null, null, null));
     }