Introduction:
In today’s micro-service architecture landscape, calling external services efficiently is crucial for building high-performance applications. Asynchronous and reactive programming paradigms offer great benefits in terms of scalability and responsiveness. However, handling multiple responses from Spring WebClient Mono objects in parallel while ensuring synchronization can be challenging. In this article, we will explore an approach to wait for multiple Spring WebClient Mono responses and combine them effectively without compromising the benefits of the reactive API.
Understanding the Challenge
1.1 The Reactive API and Non-Blocking Calls
1.2 Combining Parallel Requests: The Dilemma of Blocking
Initial Implementation
2.1 Sample Code Overview
2.2 Limitation: “Done” Printing Before Responses
2.3 The Need for Blocking Without Hindering Reactiveness
Enhanced Solution
3.1 Introducing CompletableFuture
3.2 Leveraging Mono.zip for Parallelism and Synchronization
3.3 Handling the Completed Flux and Obtaining Responses
Putting It All Together
4.1 Implementation Walkthrough and Explanation
4.2 Verifying the Results: Printing the Responses
4.3 Completing the Computation and Measuring Performance
Conclusion:
Waiting for multiple Spring WebClient Mono responses in parallel while achieving synchronization is possible without compromising the benefits of the reactive API. By utilizing CompletableFuture and Mono.zip, we can combine the responses effectively and ensure all computations are completed. This approach allows us to harness the power of reactive programming while maintaining control over the flow of execution.
