ChatClient.getInstance().chatManager().getEnterpriseWelcome(new ValueCallBack() {
            @Override
            public void onSuccess(String value) {
                Log.i("TAG value", value);
                String  enterpriseWelcome=value;
                if (!TextUtils.isEmpty(value)) {
                    ChatClient.getInstance().chatManager().getCurrentSessionId(toChatUsername, new ValueCallBack() {//toChatUsername替换为自己的IM服务号
                        @Override
                        public void onSuccess(String value) {
                            Log.e("TAG  value:", value + "  当返回value不为空时，则返回的当前会话的会话ID，也就是说会话正在咨询中，不需要发送欢迎语");
                            if (value.isEmpty()) {//
                                Message message = Message.createReceiveMessage(Message.Type.TXT);

                                EMTextMessageBody body = null;

                                body = new EMTextMessageBody(enterpriseWelcome);

                                message.setFrom(toChatUsername);//toChatUsername替换为自己的IM服务号

                                message.addBody(body);

                                message.setMsgTime(System.currentTimeMillis());

                                message.setStatus(Message.Status.SUCCESS);

                                message.setMsgId(UUID.randomUUID().toString());

                                ChatClient.getInstance().chatManager().saveMessage(message);

                                messageList.refresh();
                            }
                        }

                        @Override
                        public void onError(int error, String errorMsg) {

                        }
                    });
                }

            }

            @Override
            public void onError(int error, String errorMsg) {

            }
        });