関連ワード:  how to sort map keys in java 8    how to sort map based on key in java 8    how to sort map by value in java 8    how to sort hashmap by keys in java 8    how to get map keys as list in java 8    how to sort hashmap by value in java 8    how to sort hashmap based on value key in java 8    how to get key from map in java 8    how to get value from map using key in java 8    how to get all keys from map in java 8