public static void updateTransactionNameFromHandler()

in apm-agent-plugins/apm-spring-webmvc/apm-spring-webmvc-spring5/src/main/java/co/elastic/apm/agent/springwebmvc/AbstractSpringTransactionNameInstrumentation.java [107:156]
44 lines of code
8 McCabe index (conditional complexity)

        public static <HttpServletRequest> void updateTransactionNameFromHandler(ServletRequestAdapter<HttpServletRequest, ?> adapter, HttpServletRequest request, Object handler) {
            final Transaction<?> transaction = tracer.currentTransaction();
            if (transaction == null) {
                return;
            }
            final String className;
            final String methodName;
            if (handler instanceof HandlerMethod) {
                HandlerMethod handlerMethod = ((HandlerMethod) handler);
                className = handlerMethod.getBeanType().getSimpleName();
                methodName = handlerMethod.getMethod().getName();
            } else {
                className = handler.getClass().getSimpleName();
                methodName = null;
            }

            if (!className.isEmpty() && methodName != null) {
                TransactionNameUtils.setNameFromClassAndMethod(
                    className,
                    methodName,
                    transaction.getAndOverrideName(PRIORITY_HIGH_LEVEL_FRAMEWORK)
                );
            } else if (webConfig.isUsePathAsName()) {
                // When method name or class name are not known, we treat the calculated name as a fallback only, thus using lower priority.
                // If delegating to a Servlet, this still allows the better servlet naming default.
                TransactionNameUtils.setNameFromHttpRequestPath(
                    adapter.getMethod(request),
                    adapter.getServletPath(request),
                    adapter.getPathInfo(request),
                    transaction.getAndOverrideName(PRIORITY_LOW_LEVEL_FRAMEWORK + 1),
                    webConfig.getUrlGroups()
                );
            } else if (!className.isEmpty()) {
                // if we are here, then method name is null, thus using lower priority
                TransactionNameUtils.setNameFromClassAndMethod(
                    className,
                    methodName,
                    transaction.getAndOverrideName(PRIORITY_LOW_LEVEL_FRAMEWORK + 1)
                );
            } else {
                // Class name is empty - probably an anonymous handler class
                StringBuilder transactionName = transaction.getAndOverrideName(PRIORITY_LOW_LEVEL_FRAMEWORK + 1);
                if (transactionName != null) {
                    transactionName.append(adapter.getMethod(request)).append(" unknown route");
                }
            }

            transaction.setFrameworkName(FRAMEWORK_NAME);
            transaction.setFrameworkVersion(VersionUtils.getVersion(HandlerMethod.class, "org.springframework", "spring-web"));
        }