Follow-up · depth 7
How would you explain CompletableFuture Composition to a junior engineer?
How would you explain CompletableFuture Composition to a junior engineer?
Answers use simple, clear English.
Quick interview answer
Explain CompletableFuture Composition in one sentence, then a tiny example, then one “don’t do this” tip. Baseline: supplyAsync runs async task; thenApply transforms; thenCompose flattens nested futures; allOf waits for batch. Exceptionally/handle for error paths.
Detailed answer
Junior-friendly explanation of CompletableFuture Composition: Plain English: Baseline: supplyAsync runs async task; thenApply transforms; thenCompose flattens nested futures; allOf waits for batch. Exceptionally/handle for error paths. Tiny example: Aggregate microservice responses: CompletableFuture.allOf(userF, ordersF).thenApply(...). One warning: Blocking get() on async chain in request thread; lost exceptions without handle.
Full explanation
Keep jargon low, then layer detail. supplyAsync runs async task; thenApply transforms; thenCompose flattens nested futures; allOf waits for batch. Exceptionally/handle for error paths.
Follow-up questions
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Parent context — CompletableFuture Composition
Baseline: supplyAsync runs async task; thenApply transforms; thenCompose flattens nested futures; allOf waits for batch. Exceptionally/handle for error paths.
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