BATCH-1118: Modified StepListenerFactoryBean so that listener methods specified via annotations or the metaDataMap are checked for correct signatures. This allows incorrect methods to fail eagerly. For added flexibility, methods are also allowed if they do not specify any parameters.

spring-batch-infrastructure/src/main/java/org/springframework/batch/support/MethodInvokerUtils.java

@@ -50,18 +50,34 @@ public class MethodInvokerUtils {
 			Class<?>... paramTypes) {
 		Assert.notNull(object, "Object to invoke must not be null");
 		Method method = ClassUtils.getMethodIfAvailable(object.getClass(), methodName, paramTypes);
-		// if no method was found for the given parameters, and the parameters
-		// aren't required
-		if (method == null && !paramsRequired) {
-			// try with no params
-			method = ClassUtils.getMethodIfAvailable(object.getClass(), methodName, new Class[] {});
-		}
 		if (method == null) {
-			return null;
+			String errorMsg = "no method found with name [" + methodName + "] on class ["
+					+ object.getClass().getSimpleName() + "] compatable with the signature ["
+					+ getParamTypesString(paramTypes) + "].";
+			Assert.isTrue(!paramsRequired, errorMsg);
+			// if no method was found for the given parameters, and the
+			// parameters aren't required, then try with no params
+			method = ClassUtils.getMethodIfAvailable(object.getClass(), methodName, new Class[] {});
+			Assert.notNull(method, errorMsg);
 		}
-		else {
-			return new SimpleMethodInvoker(object, method);
+		return new SimpleMethodInvoker(object, method);
+	}
+
+	/**
+	 * Create a String representation of the array of parameter types.
+	 * 
+	 * @param paramTypes
+	 * @return String
+	 */
+	public static String getParamTypesString(Class<?>... paramTypes) {
+		StringBuffer paramTypesList = new StringBuffer("(");
+		for (int i = 0; i < paramTypes.length; i++) {
+			paramTypesList.append(paramTypes[i].getSimpleName());
+			if (i + 1 < paramTypes.length) {
+				paramTypesList.append(", ");
+			}
 		}
+		return paramTypesList.append(")").toString();
 	}
 
 	/**