public Object decode()

in dubbo-rpc-extensions/dubbo-rpc-rocketmq/src/main/java/org/apache/dubbo/rpc/rocketmq/codec/DecodeableRpcInvocation.java [107:223]
102 lines of code
25 McCabe index (conditional complexity)

    public Object decode(Channel channel, InputStream input) throws IOException {
        URL url = channel.getUrl();
        ObjectInput in = CodecSupport.getSerialization(url)
            .deserialize(url, input);
        this.put(SERIALIZATION_ID_KEY, serializationType);

        String dubboVersion = in.readUTF();
        request.setVersion(dubboVersion);
        setAttachment(DUBBO_VERSION_KEY, dubboVersion);

        String path = in.readUTF();
        setAttachment(PATH_KEY, path);
        String version = in.readUTF();
        setAttachment(VERSION_KEY, version);

        setMethodName(in.readUTF());

        String desc = in.readUTF();
        setParameterTypesDesc(desc);

        ClassLoader originClassLoader = Thread.currentThread().getContextClassLoader();
        try {
            Object[] args = RocketMQCodec.EMPTY_OBJECT_ARRAY;
            Class<?>[] pts = RocketMQCodec.EMPTY_CLASS_ARRAY;
            if (desc.length() > 0) {
                FrameworkServiceRepository repository = frameworkModel.getServiceRepository();
                List<ProviderModel> providerModels = repository.lookupExportedServicesWithoutGroup(keyWithoutGroup(path, version));
                ServiceDescriptor serviceDescriptor = null;
                if (CollectionUtils.isNotEmpty(providerModels)) {
                    for (ProviderModel providerModel : providerModels) {
                        serviceDescriptor = providerModel.getServiceModel();
                        if (serviceDescriptor != null) {
                            break;
                        }
                    }
                }
                if (serviceDescriptor == null) {
                    // Unable to find ProviderModel from Exported Services
                    for (ApplicationModel applicationModel : frameworkModel.getApplicationModels()) {
                        for (ModuleModel moduleModel : applicationModel.getModuleModels()) {
                            serviceDescriptor = moduleModel.getServiceRepository().lookupService(path);
                            if (serviceDescriptor != null) {
                                break;
                            }
                        }
                    }
                }

                if (serviceDescriptor != null) {
                    MethodDescriptor methodDescriptor = serviceDescriptor.getMethod(getMethodName(), desc);
                    if (methodDescriptor != null) {
                        pts = methodDescriptor.getParameterClasses();
                        this.setReturnTypes(methodDescriptor.getReturnTypes());

                        // switch TCCL
                        if (CollectionUtils.isNotEmpty(providerModels)) {
                            if (providerModels.size() == 1) {
                                Thread.currentThread().setContextClassLoader(providerModels.get(0).getClassLoader());
                            } else {
                                // try all providerModels' classLoader can load pts, use the first one
                                for (ProviderModel providerModel : providerModels) {
                                    ClassLoader classLoader = providerModel.getClassLoader();
                                    boolean match = true;
                                    for (Class<?> pt : pts) {
                                        try {
                                            if (!pt.equals(classLoader.loadClass(pt.getName()))) {
                                                match = false;
                                            }
                                        } catch (ClassNotFoundException e) {
                                            match = false;
                                        }
                                    }
                                    if (match) {
                                        Thread.currentThread().setContextClassLoader(classLoader);
                                        break;
                                    }
                                }
                            }
                        }
                    }
                }

                if (pts == RocketMQCodec.EMPTY_CLASS_ARRAY) {
                    if (!RpcUtils.isGenericCall(desc, getMethodName()) && !RpcUtils.isEcho(desc, getMethodName())) {
                        throw new IllegalArgumentException("Service not found:" + path + ", " + getMethodName());
                    }
                    pts = ReflectUtils.desc2classArray(desc);
                }
//                }

                args = new Object[pts.length];
                for (int i = 0; i < args.length; i++) {
                    args[i] = in.readObject(pts[i]);
                }
            }
            setParameterTypes(pts);

            Map<String, Object> map = in.readAttachments();
            if (CollectionUtils.isNotEmptyMap(map)) {
                addObjectAttachments(map);
            }

            setArguments(args);
            String targetServiceName = buildKey(getAttachment(PATH_KEY),
                getAttachment(GROUP_KEY),
                getAttachment(VERSION_KEY));
            setTargetServiceUniqueName(targetServiceName);
        } catch (ClassNotFoundException e) {
            throw new IOException(StringUtils.toString("Read invocation data failed.", e));
        } finally {
            Thread.currentThread().setContextClassLoader(originClassLoader);
            if (in instanceof Cleanable) {
                ((Cleanable) in).cleanup();
            }
        }
        return this;
    }