一不小心掉入了 Java Interface 的陷阱

public interface PostTask {    void process();}

public class SimpleResult implements BaseResult {}

// 请求处理的一部分逻辑SimpleResult result = new SimpleResult();...// 处理过程中，会往后置任务列表加入任务result.addPostTask(() -> { ...发消息... });...// 在返回结果之前，会对所有的后置任务进行遍历执行后置任务PostTaskUtil.process(result.PostTaskList());...

public class PostTaskUtil {    public static void process(List<PostTask> postTasks) {        if(CollectionUtils.isEmpty(postTasks)){            return;        }        Iterator<PostTask> iterator = postTasks.iterator();        while (iterator.hasNext()){            PostTask postTask = iterator.next();            if (postTask == null) {                return;            }            postTask.process();            iterator.remove();        }    }}

import java.util.ArrayList;import java.util.List;import java.util.concurrent.CompletableFuture;import java.util.concurrent.Executors;
public class InterfaceBugTest {    public static void main(String[] args) throws InterruptedException {        List<CompletableFuture<Boolean>> futures = new ArrayList<>();        for (int i = 0; i < 10; i++) {            int finalI = i;            CompletableFuture<Boolean> future = CompletableFuture.supplyAsync(() -> {                Test test = new Test();                test.add(finalI);                System.out.println(STR."\{finalI}: \{test.list.toString()}");                return true;            }, Executors.newVirtualThreadPerTaskExecutor());            futures.add(future);        }
        CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).join();        System.out.println(ITest.list);    }
    static class Test implements ITest { }
    interface ITest {        List<Integer> list = new ArrayList<>();
        default void add(Integer num) {            list.add(num);        }    }}

6: [0, 9, 6]1: [0, 9, 6, 7, 8, 4, 5, 3, 2, 1]9: [0, 9, 6]7: [0, 9, 6, 7]2: [0, 9, 6, 7, 8, 4, 5, 3, 2, 1]3: [0, 9, 6, 7, 8, 4, 5, 3]Exception in thread "main" java.util.concurrent.CompletionException: java.util.ConcurrentModificationException  at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:315)  at java.base/java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:320)  at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1770)  at java.base/java.util.concurrent.ThreadPerTaskExecutor$TaskRunner.run(ThreadPerTaskExecutor.java:314)  at java.base/java.lang.VirtualThread.run(VirtualThread.java:329)Caused by: java.util.ConcurrentModificationException  at java.base/java.util.ArrayList$Itr.checkForComodification(ArrayList.java:1096)  at java.base/java.util.ArrayList$Itr.next(ArrayList.java:1050)  at java.base/java.util.AbstractCollection.toString(AbstractCollection.java:458)  at com.zh.next.test.InterfaceBugTest.lambda$main$0(InterfaceBugTest.java:16)  at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1768)

// List<Integer> list = new ArrayList<>();List<Integer> list = new CopyOnWriteArrayList<>();

public interface BaseResult extends Serializable, IResult {}