BackGroundTask 后台任务

APIException.java

public class APIException extends RuntimeException {

    private int code;

    private String msg;

    public APIException(int code, String msg) {
        this.code = code;
        this.msg = msg;
    }

    public APIException(String msg) {
        this.msg = msg;
    }


    public int getCode() {
        return code;
    }

    public String getMsg() {
        return msg;
    }
}

BgTask.java

public interface BgTask<T> {
     T execute() throws Exception;
}

BgTaskExecutor.java

public class BgTaskExecutor {
    public static Executor executor = Executors.newFixedThreadPool(5);

    public static <T> void execute(BgTask<T> bgTask, BgTaskCallback<T> callback) {
        executor.execute(() -> {

            try {
                T result = bgTask.execute();
                callback.respData(result);
            } catch (APIException apiException) {
                callback.respFail(apiException.getCode(), apiException.getMsg());
            } catch (Throwable e) {
                callback.respFail(-1, "接口异常，请稍后再试");
            }
        });
    }

    public static abstract class BgTaskCallback<T> {

        private final Handler handler = new Handler(Looper.getMainLooper());

        private void runMain(Runnable r) {
            handler.post(r);
        }

        public void respData(T data) {
            runMain(() -> onData(data));
        }

        public void respFail(String message) {
            respFail(-1, message);
        }

        public void respFail(int code, String message) {
            runMain(() -> {
                onFail(code, message);
                return;
            });
        }


        protected abstract void onData(T data);

        protected abstract void onFail(int code, String message);

    }

}