public static Channel getChannel()

in core/src/main/java/org/apache/seata/core/rpc/netty/ChannelManager.java [288:416]
108 lines of code
40 McCabe index (conditional complexity)

    public static Channel getChannel(String resourceId, String clientId, boolean tryOtherApp) {
        Channel resultChannel = null;

        String[] clientIdInfo = readClientId(clientId);

        if (clientIdInfo == null || clientIdInfo.length != 3) {
            throw new FrameworkException("Invalid Client ID: " + clientId);
        }

        if (StringUtils.isBlank(resourceId)) {
            if (LOGGER.isInfoEnabled()) {
                LOGGER.info("No channel is available, resourceId is null or empty");
            }
            return null;
        }

        String targetApplicationId = clientIdInfo[0];
        String targetIP = clientIdInfo[1];
        int targetPort = Integer.parseInt(clientIdInfo[2]);

        ConcurrentMap<String, ConcurrentMap<String, ConcurrentMap<Integer,
            RpcContext>>> applicationIdMap = RM_CHANNELS.get(resourceId);

        if (targetApplicationId == null || applicationIdMap == null ||  applicationIdMap.isEmpty()) {
            if (LOGGER.isInfoEnabled()) {
                LOGGER.info("No channel is available for resource[{}]", resourceId);
            }
            return null;
        }

        ConcurrentMap<String, ConcurrentMap<Integer, RpcContext>> ipMap = applicationIdMap.get(targetApplicationId);

        if (ipMap != null && !ipMap.isEmpty()) {
            // Firstly, try to find the original channel through which the branch was registered.
            ConcurrentMap<Integer, RpcContext> portMapOnTargetIP = ipMap.get(targetIP);
            if (portMapOnTargetIP != null && !portMapOnTargetIP.isEmpty()) {
                RpcContext exactRpcContext = portMapOnTargetIP.get(targetPort);
                if (exactRpcContext != null) {
                    Channel channel = exactRpcContext.getChannel();
                    if (channel.isActive()) {
                        resultChannel = channel;
                        if (LOGGER.isDebugEnabled()) {
                            LOGGER.debug("Just got exactly the one {} for {}", channel, clientId);
                        }
                    } else {
                        if (portMapOnTargetIP.remove(targetPort, exactRpcContext)) {
                            if (LOGGER.isInfoEnabled()) {
                                LOGGER.info("Removed inactive {}", channel);
                            }
                        }
                    }
                }

                // The original channel was broken, try another one.
                if (resultChannel == null) {
                    for (ConcurrentMap.Entry<Integer, RpcContext> portMapOnTargetIPEntry : portMapOnTargetIP
                        .entrySet()) {
                        Channel channel = portMapOnTargetIPEntry.getValue().getChannel();

                        if (channel.isActive()) {
                            resultChannel = channel;
                            if (LOGGER.isInfoEnabled()) {
                                LOGGER.info(
                                    "Choose {} on the same IP[{}] as alternative of {}", channel, targetIP, clientId);
                            }
                            break;
                        } else {
                            if (portMapOnTargetIP.remove(portMapOnTargetIPEntry.getKey(),
                                portMapOnTargetIPEntry.getValue())) {
                                if (LOGGER.isInfoEnabled()) {
                                    LOGGER.info("Removed inactive {}", channel);
                                }
                            }
                        }
                    }
                }
            }

            // No channel on the this app node, try another one.
            if (resultChannel == null) {
                for (ConcurrentMap.Entry<String, ConcurrentMap<Integer, RpcContext>> ipMapEntry : ipMap
                    .entrySet()) {
                    if (ipMapEntry.getKey().equals(targetIP)) { continue; }

                    ConcurrentMap<Integer, RpcContext> portMapOnOtherIP = ipMapEntry.getValue();
                    if (portMapOnOtherIP == null || portMapOnOtherIP.isEmpty()) {
                        continue;
                    }

                    for (ConcurrentMap.Entry<Integer, RpcContext> portMapOnOtherIPEntry : portMapOnOtherIP.entrySet()) {
                        Channel channel = portMapOnOtherIPEntry.getValue().getChannel();

                        if (channel.isActive()) {
                            resultChannel = channel;
                            if (LOGGER.isInfoEnabled()) {
                                LOGGER.info("Choose {} on the same application[{}] as alternative of {}", channel, targetApplicationId, clientId);
                            }
                            break;
                        } else {
                            if (portMapOnOtherIP.remove(portMapOnOtherIPEntry.getKey(),
                                portMapOnOtherIPEntry.getValue())) {
                                if (LOGGER.isInfoEnabled()) {
                                    LOGGER.info("Removed inactive {}", channel);
                                }
                            }
                        }
                    }
                    if (resultChannel != null) { break; }
                }
            }
        }

        if (resultChannel == null && tryOtherApp) {
            resultChannel = tryOtherApp(applicationIdMap, targetApplicationId);

            if (resultChannel == null) {
                if (LOGGER.isInfoEnabled()) {
                    LOGGER.info("No channel is available for resource[{}] as alternative of {}", resourceId, clientId);
                }
            } else {
                if (LOGGER.isInfoEnabled()) {
                    LOGGER.info("Choose {} on the same resource[{}] as alternative of {}", resultChannel, resourceId, clientId);
                }
            }
        }

        return resultChannel;

    }