Springboot 中的并发修改异常

Question

我是 Spring Boot 项目的新手我收到以下错误

2021-10-10 06:43:31,378 ERROR [http-nio-9000-exec-216] org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.util.ConcurrentModificationException] with root cause
java.util.ConcurrentModificationException: null 

org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.util.ConcurrentModificationException: java.util.ConcurrentModificationException] with root cause
java.util.ConcurrentModificationException: null
        at java.base/java.util.TreeMap$KeySpliterator.tryAdvance(TreeMap.java:2765)
        at java.base/java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:127)
        at java.base/java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:502)
        at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:488)
        at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
        at java.base/java.util.stream.FindOps$FindTask.doLeaf(FindOps.java:319)
        at java.base/java.util.stream.AbstractShortCircuitTask.compute(AbstractShortCircuitTask.java:115)
        at java.base/java.util.concurrent.CountedCompleter.exec(CountedCompleter.java:746)
        at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
        at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1020)
        at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1656)
        at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1594)
        at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:183) 

public SortedSet<AWSInstance> awsInstances = Collections.synchronizedSortedSet(new TreeSet<>());

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