public static void main()

in core/java8actionloop/lib/src/Launcher.java [108:205]
88 lines of code
19 McCabe index (conditional complexity)

    public static void main(String[] args) throws Exception {

        initMain(args);

        // exit after main class loading if "exit" specified
        // used to check healthy launch after init
        if(args.length >1 && args[1] == "-exit")
            System.exit(0);

        // install a security manager to prevent exit
        installSecurityManager();

        BufferedReader in = new BufferedReader(
                new InputStreamReader(System.in, "UTF-8"));
        PrintWriter out = new PrintWriter(
                new OutputStreamWriter(
                        new FileOutputStream("/dev/fd/3"), "UTF-8"));
        JsonParser json = new JsonParser();
        JsonObject emptyForJsonObject = json.parse("{}").getAsJsonObject();
        JsonArray emptyForJsonArray = json.parse("[]").getAsJsonArray();
        Boolean isJsonObjectParam = true;
        String input = "";
        while (true) {
            try {
                input = in.readLine();
                if (input == null)
                    break;
                JsonElement element = json.parse(input);
                JsonObject payloadForJsonObject = emptyForJsonObject.deepCopy();
                JsonArray payloadForJsonArray = emptyForJsonArray.deepCopy();
                HashMap<String, String> env = new HashMap<String, String>();
                if (element.isJsonObject()) {
                    // collect payload and environment
                    for (Map.Entry<String, JsonElement> entry : element.getAsJsonObject().entrySet()) {
                        if (entry.getKey().equals("value")) {
                            if (entry.getValue().isJsonObject())
                                payloadForJsonObject = entry.getValue().getAsJsonObject();
                            else {
                                payloadForJsonArray = entry.getValue().getAsJsonArray();
                                isJsonObjectParam = false;
                            }
                        } else {
                            env.put(String.format("__OW_%s", entry.getKey().toUpperCase()),
                                    entry.getValue().getAsString());
                        }
                    }
                    augmentEnv(env);
                }

                Method m = null;
                if (isJsonObjectParam) {
                    m = mainClass.getMethod(mainMethodName, new Class[] { JsonObject.class });
                } else {
                    m = mainClass.getMethod(mainMethodName, new Class[] { JsonArray.class });
                }
                m.setAccessible(true);
                int modifiers = m.getModifiers();
                if ((m.getReturnType() != JsonObject.class && m.getReturnType() != JsonArray.class) || !Modifier.isStatic(modifiers) || !Modifier.isPublic(modifiers)) {
                    throw new NoSuchMethodException(mainMethodName);
                }
                mainMethod = m;

                Object response;
                if (isJsonObjectParam) {
                    response = invokeMain(payloadForJsonObject, env);
                } else {
                    response = invokeMain(payloadForJsonArray, env);
                }
                out.println(response.toString());
            } catch(NullPointerException npe) {
                System.out.println("the action returned null");
                npe.printStackTrace(System.err);
                JsonObject error = new JsonObject();
                error.addProperty("error", "the action returned null");
                out.println(error.toString());
                out.flush();
            } catch(InvocationTargetException ite) {
                Throwable ex = ite;
                if(ite.getCause() != null)
                    ex = ite.getCause();
                ex.printStackTrace(System.err);
                JsonObject error = new JsonObject();
                error.addProperty("error", ex.getMessage());
                out.println(error.toString());
                out.flush();
            } catch (Exception ex) {
                ex.printStackTrace(System.err);
                JsonObject error = new JsonObject();
                error.addProperty("error", ex.getMessage());
                out.println(error.toString());
                out.flush();
            }
            out.flush();
            System.out.flush();
            System.err.flush();
        }
        uninstallSecurityManager();
    }