public void doAction()

in maven/core/src/main/java/org/apache/karaf/maven/command/HttpProxyCommand.java [64:150]
75 lines of code
32 McCabe index (conditional complexity)

    public void doAction(String prefix, Dictionary<String, Object> config) throws Exception {
        if (add && (change || remove) || change && remove) {
            System.err.println("Please specify only one of --add/--change/--remove");
            return;
        }

        if (id == null || "".equals(id.trim())) {
            System.err.println("Please specify ID of HTTP proxy");
            return;
        }

        if (mavenSettings.getProxies() == null) {
            mavenSettings.setProxies(new LinkedList<>());
        }
        Optional<Proxy> existingProxy = mavenSettings.getProxies().stream()
                .filter((p) -> id.equals(p.getId())).findAny();

        if (add) {
            if (hostPort == null || "".equals(hostPort.trim())) {
                System.err.println("Please specify host:port of new HTTP proxy");
                return;
            }
            if (existingProxy.isPresent()) {
                System.err.printf("HTTP proxy with ID \"%s\" is already configured\n", id);
                return;
            }
        } else if (!existingProxy.isPresent()) {
            System.err.printf("Can't find HTTP proxy with ID \"%s\"\n", id);
            return;
        }

        boolean hasUsername = username != null && !"".equals(username.trim());
        boolean hasPassword = password != null && !"".equals(password.trim());
        boolean hasCredentials = hasUsername && hasPassword;

        if ((hasUsername && !hasPassword) || (!hasUsername && hasPassword)) {
            System.err.println("Please specify both username and password");
            return;
        }

        Proxy proxy = null;
        if (add) {
            proxy = new Proxy();
            proxy.setId(id);
            mavenSettings.getProxies().add(proxy);
        } else if (change) {
            proxy = existingProxy.get(); // should be there
        } else /*if (remove)*/ {
            // remove
            List<Proxy> newProxies = mavenSettings.getProxies().stream()
                    .filter((p) -> !id.equals(p.getId())).collect(Collectors.toList());
            mavenSettings.setProxies(newProxies);
        }

        if (add || change) {
            proxy.setActive(true);
            proxy.setProtocol("http");
            if (nonProxyHosts != null && !"".equals(nonProxyHosts.trim())) {
                proxy.setNonProxyHosts(nonProxyHosts);
            }
            if (hostPort != null && !"".equals(hostPort.trim())) {
                if (hostPort.contains(":")) {
                    proxy.setHost(hostPort.substring(0, hostPort.indexOf(':')));
                    proxy.setPort(Integer.parseInt(hostPort.substring(hostPort.indexOf(':') + 1)));
                } else {
                    proxy.setHost(hostPort);
                    proxy.setPort(3128);
                }
            }
            if (hasCredentials) {
                proxy.setUsername(username);
                proxy.setPassword(password);
            }
        }

        updateSettings(prefix, config);

        Configuration cmConfig = cm.getConfiguration(PID);
        cmConfig.update(config);

        // list (also after --add or --remove)
        if (showPasswords) {
            session.execute("maven:http-proxy-list -x");
        } else {
            session.execute("maven:http-proxy-list");
        }
    }