Android端创建Conversation对象，老返回null

2720529059 2018-06-22 10:26 553 0

Conversation chat = JMessageClient.getSingleConversation("17743541292","");
或者 Conversation chat = JMessageClient.getSingleConversation("17743541292");
或者 Conversation chat = Conversation.createSingleConversation("17743541292",“”);
或者 Conversation chat = Conversation.createSingleConversation("17743541292");

都返回null
请问该如何解决？