Check if a objekt is an array

I am currently trying to take apart a objekt with logic like this

public String toString(Object x) throws IllegalArgumentException, IllegalAccessException {
    if(i > 10000) {
        throw new StackOverflowError("The Deserilesation of an objekt has overflowen");
    }
    i++;
    if(x instanceof String) {
        return String.valueOf(x);
    }else if(x instanceof Integer) {
        return String.valueOf(x);
    }else if(x instanceof Boolean) {
        return String.valueOf(x);
    }else if(x instanceof Long) {
        return String.valueOf(x);
    }else if(x instanceof Float) {
        return String.valueOf(x);   
    }else if(x instanceof Double){
        return String.valueOf(x);   
    }else if(x instanceof Byte){
        return String.valueOf(x);   
    }else if(x instanceof Character){
        return String.valueOf(x);   
    }else {
        String toreturn = "{";
        for(Field f : x.getClass().getDeclaredFields()) {
            f.setAccessible(true);
            try {
                toreturn += f.getName() + ":"+ toString(f.get(x)) + " ";
            }catch (NullPointerException e) {
                toreturn += f.getName() + ":Null ";
                }
            }
            toreturn += "}";
    return toreturn;
}

but if there is a int[] then i will get the standert tostring like 00000@000000, my question how can i deteckt that i have an array, i tryed if(x instanceof Array) but there is not array class