AsyncTask中执行参数的类型安全替代方案

Question

There are two ways to pass arguments to an AsyncTask

1. Define the first generic parameter and use a list/array of this typed and pass it through execute()
2. Pass all necessary arguments through the constructor, store them in a field and access them in execute

I find the first approach more readable, but sometimes it lacks flexibility in terms of type-safety, for instance if you want to pass a String, an Integer and a Boolean it seems unclear how to approach this.

public Result doInBackground(String... params) {
   String param1 = params[0];
   int param2 = Integer.valueOf(params[1]);
   boolean param3 = Boolean.valueOf(params[2]);
   // ...
}

String parsing, putting it in a Bundle , etc. There is always a solution, but I find this unpleasing from a semantic/method signature point of view. Any alternatives?

Answer 1

Why not create a Class Holder for Example

static Class Holder {
  int i;
  String s;
  boolean b;
}

public Result doInBackground(Holder... params) {
   Holder holder = params[0];
   String holder.s;
  // ...
 }

then send it to the doBackground() through the execute().. i did it a lot of times when i want to send to web

this is just an example of crouse. Hope it helps.

Answer 2

You could use Loaders instead.

It can be cumbersome to start with, but you won't have any type-safe issues then, because it works in a complete different manner.

The main power of loaders is that they work with a manager that is bound to the lifecycle of the Activity/Fragment.