我试着从Kafka的Spark中读到如下主题：

Map<TopicAndPartition, Long> map = new HashMap<>();
        map.put(new TopicAndPartition("A", 0), 1L);
        map.put(new TopicAndPartition("B", 0), 1L);

        JavaInputDStream<Map.Entry> topicMessages = KafkaUtils.createDirectStream(
                                                                            jssc,
                                                                            String.class,
                                                                            String.class,
                                                                            StringDecoder.class,
                                                                            StringDecoder.class,
                                                                            Map.Entry.class,
                                                                            kafkaParams,
                                                                            map,
                                                                            messageAndMetadata -> 
                                                                                new AbstractMap.SimpleEntry<>(messageAndMetadata.topic(),
                                                                                                              messageAndMetadata.message())
                                                                          );

现在topicmessage以键和值格式显示所有值，如下所示：

A="04/15/2015","18:44:28"
A="04/15/2015","18:44:28"
A="04/15/2015","18:44:28"
B="04/15/2016","18:44:28"
B="04/15/2014","18:44:28"

如何提取特定主题的值。
类似于下面的主题 B ```
"04/15/2016","18:44:28"
"04/15/2014","18:44:28"