java.lang.IllegalStateException: Duplicate key xxxx
    at java.base/java.util.stream.Collectors.duplicateKeyException(Collectors.java:135)
    at java.base/java.util.stream.Collectors.lambda$uniqKeysMapAccumulator$1(Collectors.java:182)
    at java.base/java.util.stream.ReduceOps$3ReducingSink.accept(ReduceOps.java:169)
    at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179)
    at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)
    at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762)
    at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:27

Map<Long, String> map = orderList.stream()
        .collect(Collectors.toMap(Order::getId, Order::getPrice, (v1, v2) -> v1));

Map<Long, String> map = orderList.stream()
        .collect(Collectors.toMap(Order::getId, Order::getPrice, (v1, v2) -> v2));