Callable/Future Real world Example

[anuj guptaa]

Hi

I am learning java concurrent package these days. Today i learned about the Callable interface ,Future/FutureTask, Executor Service. I understood what these are and how to use them.

But I would like to know a real life example for the Callable interface as i have mostly used Runnable in my projects.


Has anyone used Callable in their project . Please throw some light here.

Thanks
Anuj

[Steve Luke]

anuj guptaa wrote:But I would like to know a real life example for the Callable interface as i have mostly used Runnable in my projects.

A Callable is just like a Runnable, except it returns a value. It is used to provide a simple, Runnable-like API to insert your executable code into FutureTasks, where some return value is expected. Internally, FutureTask probably makes use of Runnable to execute the code, but in addition, will do something with the results (such as notify get()ers that it is ready).

Real-world use would be any long task that produces a result - get something from a database and turn it into an Object, make a long calculation with a result, query a web application, get some data, do something with that data, generate output...

[anuj guptaa]

Thanks Steve!! Hope i will soon get a chance to use callable in my project..

[Jayesh A Lalwani]

There is an example of using Callable with a Thread Pool in this FAQ

[anuj guptaa]

Thanks Jayesh!! This link is quiet helpful !!