tailieunhanh - Teach Yourself J2EE in 21 Days phần 5

Ngược lại, kêu gọi tạo ra () cho một hạt đậu kỳ họp không quốc tịch không nhất thiết gây ra được gọi là các hạt cơ bản, mặc dù khách hàng sẽ có một tham chiếu đến một EJBObject sau khi thực hiện cuộc gọi này. | Java Message Service 427 Q What type of JMS message domain should be used to send a message to many receivers at the same time A To send to many receivers the publish subscribe message domain is the best choice. Q What is the difference between JMSHeader fields and JMSProperty fields A JMS header fields are defined in the JMS API and are mainly set by the JMS provider. JMS property fields are used by clients to add additional header information to a message. Q Does JMS guarantee to deliver a message in the point-to-point domain A Messages in the point-to-point domain are PERSISTENT by default and will be delivered unless they have a timeout that has expired. Point-to-point messages can be set to NON-PERSISTENT in which case the message may be lost if a provider fails. Q When should I use a durable subscription A Durable subscriptions should be used when a subscriber needs to receive messages from a topic when it is inactive. 9 Exercise To extend your knowledge of the subjects covered today try the following exercises. 1. Create a chat room application. Participants provide their name and can send messages to any topic hint use a JMS property to define the topic . Participants may read messages posted by all other participants or filter by topic. You may use predefined topic names. To assist you in this task three Java files have been provided in the exercise sub-directory for Day 9 on the accompanying CD-ROM. The and files are complete and need not be edited. These files provide the Swing code to enter and display the chat room messages onscreen. The is a starting point for you to further develop the chat server. The initial code simply uses the callback method addMessage to bounce the message back to the screen. The addMessage method uses the interface defined in . You will need to edit this file to replace this callback with code to publish the message to a topic. You then need to add a subscriber that .

crossorigin="anonymous">
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.