Hardest part
How do you think, how much changes you need to do to make your Swift service asynchronous? Do you afraid of it? You already scheduled a week for this refactoring? Oh, that‘s nice:)| import com.facebook.swift.service.ThriftMethod; | |
| import com.facebook.swift.service.ThriftService; | |
| +import com.google.common.util.concurrent.ListenableFuture; | |
| @ThriftService | |
| public interface TCalculatorService { | |
| @ThriftMethod | |
| - int calculate(int num1, int num2, TOperation op) throws TDivisionByZeroException; | |
| + ListenableFuture<Integer> calculate(int num1, int num2, TOperation op) throws TDivisionByZeroException; | |
| } |
Now it‘s time to update your service implementation. Are you ready?
| import com.example.calculator.protocol.TOperation; | |
| +import com.google.common.util.concurrent.*; | |
| import org.springframework.stereotype.Component; | |
| import com.example.calculator.service.CalculatorService; | |
| import org.springframework.beans.factory.annotation.Autowired; | |
| +import java.util.concurrent.*; | |
| + | |
| @Component | |
| public class CalculatorServiceHandler implements TCalculatorService { | |
| @Autowired | |
| CalculatorService calculatorService; | |
| + ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(10); | |
| + | |
| @Override | |
| - public int calculate(int num1, int num2, TOperation op) throws TDivisionByZeroException { | |
| + public ListenableFuture<Integer> calculate(int num1, int num2, TOperation op) throws TDivisionByZeroException { | |
| + return JdkFutureAdapters.listenInPoolThread( | |
| + scheduledExecutorService.schedule(() -> { | |
| switch(op) { | |
| case ADD: | |
| return calculatorService.add(num1, num2); | |
| @@ -32,5 +40,7 @@ | |
| default: | |
| throw new IllegalArgumentException("Unknown operation " + op); | |
| } | |
| + }, 2, TimeUnit.SECONDS) | |
| + ); | |
| } | |
| } |
Hope you noticed this ScheduledExecutorService and 2 seconds delay. You shouldn‘t use it in your real application, this is just for example of promises (unless you want to simulate work for future optimizations like this guy: http://thedailywtf.com/articles/The-Speedup-Loop )
That‘s it, now your server is asynchronous. There is more - your clients can consume your service like before in non-async manner. How cool is that?
Full source code at GitHub: https://github.com/bsideup/spring-boot-swift/tree/async
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