英文:
spring boot loop in @async mulit-thread
问题
如果我在调用doSomething()时提供索引值，索引值将为100。如何解决这个问题？
我希望索引为0、1、2、3、4。
List<CompletableFuture> futures = new ArrayList();
for (int i = 0; i < 5; i++) {
int index = i; // Capture the current value of 'i'
futures.add(CompletableFuture.runAsync(() -> doSomething(index)));
futures.add(CompletableFuture.runAsync(() -> doSomethingElse(index)));
}
CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).thenRunAsync(() -> log("已完成操作"));
英文:
If I give the index value when I call doSomething(), the index value is 100. How to solve it?
I want the index to be 0,1,2,3,4
List<CompletableFuture> futures = new ArrayList();for(
int i = 0;i<100;i++)
{
futures.add(CompletableFuture.runAsync(() -> doSomething(i)));
futures.add(CompletableFuture.runAsync(() -> doSomethingElse(i)));
}CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).thenRunAsync(()->log("Ended doing things"));
答案1
得分: 2
变量i必须是final或者effectively final。你可以使用类似于AtomicInteger的东西，或者对它进行复制，例如：
List<CompletableFuture<Void>> futures = new ArrayList<>();
for (int i = 0; i < 100; i++) {
int finalI = i;
futures.add(CompletableFuture.runAsync(() -> doSomething(finalI)));
futures.add(CompletableFuture.runAsync(() -> doSomethingElse(finalI)));
}
CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).thenRunAsync(() -> log("Ended doing things"));
英文:
Variable i must be final or effectively final. You can use somethink like AtomicInteger or make copy of it e.g.
List<CompletableFuture<Void>> futures = new ArrayList<>();
for (int i = 0; i < 100; i++) {
int finalI = i;
futures.add(CompletableFuture.runAsync(() -> doSomething(finalI)));
futures.add(CompletableFuture.runAsync(() -> doSomethingElse(finalI)));
}
CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).thenRunAsync(() -> log("Ended doing things"));
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