public static void initializeCoreConfig()

in apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java [70:132]
54 lines of code
11 McCabe index (conditional complexity)

    public static void initializeCoreConfig(String agentOptions) {
        AGENT_SETTINGS = new Properties();
        try (final InputStreamReader configFileStream = loadConfig()) {
            AGENT_SETTINGS.load(configFileStream);
            for (String key : AGENT_SETTINGS.stringPropertyNames()) {
                String value = (String) AGENT_SETTINGS.get(key);
                AGENT_SETTINGS.put(key, PropertyPlaceholderHelper.INSTANCE.replacePlaceholders(value, AGENT_SETTINGS));
            }

        } catch (Exception e) {
            LOGGER.error(e, "Failed to read the config file, skywalking is going to run in default config.");
        }

        try {
            overrideConfigBySystemProp();
        } catch (Exception e) {
            LOGGER.error(e, "Failed to read the system properties.");
        }

        agentOptions = StringUtil.trim(agentOptions, ',');
        if (!StringUtil.isEmpty(agentOptions)) {
            try {
                agentOptions = agentOptions.trim();
                LOGGER.info("Agent options is {}.", agentOptions);

                overrideConfigByAgentOptions(agentOptions);
            } catch (Exception e) {
                LOGGER.error(e, "Failed to parse the agent options, val is {}.", agentOptions);
            }
        }

        initializeConfig(Config.class);
        // reconfigure logger after config initialization
        configureLogger();
        LOGGER = LogManager.getLogger(SnifferConfigInitializer.class);

        setAgentVersion();

        if (StringUtil.isEmpty(Config.Agent.SERVICE_NAME)) {
            throw new ExceptionInInitializerError("`agent.service_name` is missing.");
        } else {
            if (StringUtil.isNotEmpty(Config.Agent.NAMESPACE) || StringUtil.isNotEmpty(Config.Agent.CLUSTER)) {
                Config.Agent.SERVICE_NAME = StringUtil.join(
                    SERVICE_NAME_PART_CONNECTOR,
                    Config.Agent.SERVICE_NAME,
                    Config.Agent.NAMESPACE,
                    Config.Agent.CLUSTER
                );
            }
        }
        if (StringUtil.isEmpty(Config.Collector.BACKEND_SERVICE)) {
            throw new ExceptionInInitializerError("`collector.backend_service` is missing.");
        }
        if (Config.Plugin.PEER_MAX_LENGTH <= 3) {
            LOGGER.warn(
                "PEER_MAX_LENGTH configuration:{} error, the default value of 200 will be used.",
                Config.Plugin.PEER_MAX_LENGTH
            );
            Config.Plugin.PEER_MAX_LENGTH = 200;
        }

        IS_INIT_COMPLETED = true;
    }