如何正确重写Runnable.run（），以便它可以接受参数？

Question

I am currently working on an android project and came across the situation, that I have to pass a function as parameter, so I browsed StackOverflow and tried out solution, to encapsulate the function with a Runnable .

The problem I'm now facing is, that the function I want to pass, expects parameters and Runnable.run() doesn't take any. So I'm currently trying to extend Runnable and override run() to let it accept parameters, which I can then pass to the actual function.

Now I'm kinda unsure, as run() is used in Thread on how I can override it, without knocking out Thread . I don't use any other Thread methods so far. Any suggested approach?

EDIT

The target is, to call these custom Runnables inside a listener method like so:

public void startRequest(RequestOperation operation, final Runnable onSuccess, final Runnable onError, final Runnable onFinished) {

    JsonObjectRequest request = new JsonObjectRequest(Request.Method.POST, instance_context.getResources().getString(R.string.base_url), null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            onSuccess.run();
            onFinished.run();
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            onError.run();
            onFinished.run();
        }
    });
    queue.add(request);
}

In best case, onSuccess is able get the response object passed, as onError gets the error .

Answer 1

Why force Runnable into being something it's not designed to be? Simply have your own interface that has the signature you require. Eg

public interface Callback<T> {
    void run(T parameter);
}

public void startRequest(RequestOperation operation, final Callback<JSONObject> onSuccess, final Callback<VolleyError> onError, final Runnable onFinished) {

    JsonObjectRequest request = new JsonObjectRequest(Request.Method.POST, instance_context.getResources().getString(R.string.base_url), null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            onSuccess.run(response);
            onFinished.run();
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            onError.run(error);
            onFinished.run();
        }
    });
    queue.add(request);
}

Or even better (if you ask me):

public interface Callback {
    void onSucces(JSONObject response);
    void onError(VolleyError error);
    void onFinished();
}

public void startRequest(RequestOperation operation, final Callback callback) {

    JsonObjectRequest request = new JsonObjectRequest(Request.Method.POST, instance_context.getResources().getString(R.string.base_url), null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            callback.onSuccess(response);
            callback.onFinished();
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            callback.onError(error);
            callback.onFinished();
        }
    });
    queue.add(request);
}

You can also make Callback generic again, if you need to:

public interface Callback<R, E> {
    void onSucces(R response);
    void onError(E error);
    void onFinished();
}

public void startRequest(RequestOperation operation, final Callback<JSONObject, VolleyError> callback) {...}

To use:

public class SimpleCallback implements Callback {
    public void onSucces(JSONObject response) {
        doSomethingWithResponse(response);
    }

    public void onError(VolleyError error) {
        doSomethingWithError(error);
    }

    void onFinished() {
        logFinishTime();
    }
}

startRequest(operation, new SimpleCallback());