Fix method may be null, and NullPointerException will be thrown in Me…

…thodUtils (apache#7606)

* Fix method may be null, and NullPointerException will be thrown in MethodUtils(apache#7605)

* Update by review

Signed-off-by: xingrufei <xingrufei@sogou-inc.com>

Co-authored-by: xingrufei <xingrufei@sogou-inc.com>

dubbo-common/src/main/java/org/apache/dubbo/common/utils/MethodUtils.java

@@ -276,6 +276,10 @@ static <T> T invokeMethod(Object object, String methodName, Object... methodPara
         Method method = findMethod(type, methodName, parameterTypes);
         T value = null;
 
+        if (method == null) {
+            throw new IllegalStateException(String.format("cannot find method %s,class: %s", methodName, type.getName()));
+        }
+
         try {
             ReflectUtils.makeAccessible(method);
             value = (T) method.invoke(object, methodParameters);