private void doHandler()

in dubbo-rpc-extensions/dubbo-rpc-rest/src/main/java/org/apache/dubbo/rpc/protocol/rest/filter/ServiceInvokeRestFilter.java [77:160]
61 lines of code
6 McCabe index (conditional complexity)

    private void doHandler(
            HttpRequest nettyHttpRequest,
            NettyHttpResponse nettyHttpResponse,
            RequestFacade request,
            URL url,
            Object originRequest, // resteasy  request
            ServiceDeployer serviceDeployer)
            throws Exception {
        PathMatcher pathMatcher = RestRPCInvocationUtil.createPathMatcher(request);

        // path NoFound 404
        if (!serviceDeployer.hashRestMethod(pathMatcher)) {
            throw new PathNoFoundException("rest service Path no found, current path info:" + pathMatcher);
        }

        // method disallowed
        if (!serviceDeployer.isMethodAllowed(pathMatcher)) {
            nettyHttpResponse.sendError(
                    405,
                    "service require request method is : "
                            + serviceDeployer.pathHttpMethods(pathMatcher)
                            + ", but current request method is: " + request.getMethod());
            return;
        }
        // compare http method and  acquire metadata by request
        InvokerAndRestMethodMetadataPair restMethodMetadataPair =
                RestRPCInvocationUtil.getRestMethodMetadataAndInvokerPair(
                        pathMatcher.compareHttpMethod(true), serviceDeployer);

        Invoker invoker = restMethodMetadataPair.getInvoker();

        RestMethodMetadata restMethodMetadata = restMethodMetadataPair.getRestMethodMetadata();

        // content-type  support judge,throw unSupportException
        acceptSupportJudge(request, restMethodMetadata.getReflectMethod().getReturnType());

        // build RpcInvocation
        RpcInvocation rpcInvocation = RestRPCInvocationUtil.createBaseRpcInvocation(request, restMethodMetadata);

        // parse method real args
        RestRPCInvocationUtil.parseMethodArgs(
                rpcInvocation, request, nettyHttpRequest, nettyHttpResponse, restMethodMetadata);

        // execute business  method invoke
        Result result = invoker.invoke(rpcInvocation);

        // set raw response
        nettyHttpResponse.setResponseBody(result.getValue());

        if (result.hasException()) {
            Throwable exception = result.getException();
            logger.error(
                    "", exception.getMessage(), "", "dubbo rest protocol provider Invoker invoke error", exception);

            if (serviceDeployer.getExceptionMapper().hasExceptionMapper(exception)) {
                ExceptionHandlerResult exceptionToResult =
                        serviceDeployer.getExceptionMapper().exceptionToResult(result.getException());
                writeResult(
                        nettyHttpResponse, request, url, exceptionToResult.getEntity(), rpcInvocation.getReturnType());
                nettyHttpResponse.setStatus(exceptionToResult.getStatus());
            } else {
                nettyHttpResponse.sendError(
                        500,
                        "\n dubbo rest business exception, error cause is: "
                                + result.getException().getCause()
                                + "\n message is: " + result.getException().getMessage()
                                + "\n stacktrace is: " + stackTraceToString(exception));
            }
        }

        try {
            RestInterceptContext restFilterContext = new RestInterceptContext(
                    url, request, nettyHttpResponse, serviceDeployer, result.getValue(), rpcInvocation);
            // set filter request
            restFilterContext.setOriginRequest(originRequest);

            // invoke the intercept chain before Result  write to  response
            executeResponseIntercepts(restFilterContext);
        } catch (Exception exception) {
            logger.error(
                    "", exception.getMessage(), "", "dubbo rest protocol execute ResponseIntercepts error", exception);
            throw exception;
        }
    }