Smart Home Automation Tool Java, API

```java
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class SmartHomeAutomation {

    private Map<String, Device> devices;
    private static final String API_KEY = "your_super_secret_api_key"; // Replace with your actual API key

    public SmartHomeAutomation() {
        this.devices = new HashMap<>();
    }

    // API endpoint to add a device
    public String addDevice(String apiKey, String deviceName, String deviceType) {
        if (!isValidApiKey(apiKey)) {
            return "Error: Invalid API key.";
        }

        if (devices.containsKey(deviceName)) {
            return "Error: Device with name '" + deviceName + "' already exists.";
        }

        Device newDevice = new Device(deviceName, deviceType);
        devices.put(deviceName, newDevice);
        return "Device '" + deviceName + "' added successfully.";
    }

    // API endpoint to turn on/off a device
    public String controlDevice(String apiKey, String deviceName, String action) {
        if (!isValidApiKey(apiKey)) {
            return "Error: Invalid API key.";
        }

        if (!devices.containsKey(deviceName)) {
            return "Error: Device '" + deviceName + "' not found.";
        }

        Device device = devices.get(deviceName);
        if (action.equalsIgnoreCase("on")) {
            device.turnOn();
            return "Device '" + deviceName + "' turned on.";
        } else if (action.equalsIgnoreCase("off")) {
            device.turnOff();
            return "Device '" + deviceName + "' turned off.";
        } else {
            return "Error: Invalid action. Use 'on' or 'off'.";
        }
    }

    // API endpoint to get device status
    public String getDeviceStatus(String apiKey, String deviceName) {
        if (!isValidApiKey(apiKey)) {
            return "Error: Invalid API key.";
        }

        if (!devices.containsKey(deviceName)) {
            return "Error: Device '" + deviceName + "' not found.";
        }

        Device device = devices.get(deviceName);
        return "Device '" + deviceName + "' is currently " + (device.isOn() ? "on" : "off") + ".";
    }


    // Helper function to validate API key
    private boolean isValidApiKey(String apiKey) {
        return API_KEY.equals(apiKey);
    }

    public static void main(String[] args) {
        SmartHomeAutomation smartHome = new SmartHomeAutomation();
        Scanner scanner = new Scanner(System.in);

        while (true) {
            System.out.println("\nSmart Home Automation Menu:");
            System.out.println("1. Add Device");
            System.out.println("2. Control Device (On/Off)");
            System.out.println("3. Get Device Status");
            System.out.println("4. Exit");
            System.out.print("Enter your choice: ");

            int choice = scanner.nextInt();
            scanner.nextLine(); // Consume newline

            switch (choice) {
                case 1:
                    System.out.print("Enter device name: ");
                    String deviceName = scanner.nextLine();
                    System.out.print("Enter device type: ");
                    String deviceType = scanner.nextLine();
                    System.out.println(smartHome.addDevice(API_KEY, deviceName, deviceType));
                    break;
                case 2:
                    System.out.print("Enter device name: ");
                    String controlDeviceName = scanner.nextLine();
                    System.out.print("Enter action (on/off): ");
                    String action = scanner.nextLine();
                    System.out.println(smartHome.controlDevice(API_KEY, controlDeviceName, action));
                    break;
                case 3:
                    System.out.print("Enter device name: ");
                    String statusDeviceName = scanner.nextLine();
                    System.out.println(smartHome.getDeviceStatus(API_KEY, statusDeviceName));
                    break;
                case 4:
                    System.out.println("Exiting Smart Home Automation.");
                    scanner.close();
                    return;
                default:
                    System.out.println("Invalid choice. Please try again.");
            }
        }
    }


    // Inner class representing a smart home device
    static class Device {
        private String name;
        private String type;
        private boolean isOn;

        public Device(String name, String type) {
            this.name = name;
            this.type = type;
            this.isOn = false;
        }

        public String getName() {
            return name;
        }

        public String getType() {
            return type;
        }

        public boolean isOn() {
            return isOn;
        }

        public void turnOn() {
            this.isOn = true;
        }

        public void turnOff() {
            this.isOn = false;
        }
    }
}
```