birt barcode tool Messaging and developing MDBs in Java

Printer ECC200 in Java Messaging and developing MDBs

Messaging and developing MDBs
Data Matrix ECC200 Creation In Java
Using Barcode generator for Java Control to generate, create ECC200 image in Java applications.
www.OnBarcode.com
Decoding Data Matrix In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
This chapter covers
PDF 417 Drawer In Java
Using Barcode printer for Java Control to generate, create PDF-417 2d barcode image in Java applications.
www.OnBarcode.com
Draw QR In Java
Using Barcode encoder for Java Control to generate, create QR Code image in Java applications.
www.OnBarcode.com
Introducing messaging concepts Building a message producer using JMS Developing MDBs
1D Barcode Encoder In Java
Using Barcode drawer for Java Control to generate, create 1D Barcode image in Java applications.
www.OnBarcode.com
Printing UCC - 12 In Java
Using Barcode encoder for Java Control to generate, create GS1-128 image in Java applications.
www.OnBarcode.com
Messaging concepts
Create Code 3/9 In Java
Using Barcode maker for Java Control to generate, create Code39 image in Java applications.
www.OnBarcode.com
Drawing Planet In Java
Using Barcode creation for Java Control to generate, create Planet image in Java applications.
www.OnBarcode.com
In this chapter we ll take a closer look at developing message-driven beans (MDBs) as well as provide you with an overview of the concepts and technologies these powerful EJB 3 components build on. First we ll introduce you to basic messaging concepts, and then we ll explore the Java Messaging Service (JMS) by creating a message producer. Finally, we ll take a look at MDBs, the EJB 3 answer to messaging. You should gain an understanding of messaging and JMS before diving into MDB for two reasons. First, most MDBs you ll encounter are glorified JMS message consumers implementing JMS interfaces (such as javax.jms.MessageListener) and using JMS components (such as javax.jms.Message). Second, for most solutions with MDB your messaging will involve much more than simply consuming messages. For the simplest of these tasks, such as sending messages, you ll have to understand JMS. This chapter assumes a basic familiarity with JMS and we offer only a brief description of it. If you re comfortable with messaging and JMS, feel free to skip to the sections on MDBs. It is good to reinforce what you know from time to time, though, so you just might want to quickly jog through the first few sections with us anyway.
Data Matrix 2d Barcode Creator In Visual Basic .NET
Using Barcode encoder for .NET Control to generate, create ECC200 image in .NET framework applications.
www.OnBarcode.com
DataMatrix Maker In Java
Using Barcode encoder for Java Control to generate, create Data Matrix ECC200 image in Java applications.
www.OnBarcode.com
4.1 Messaging concepts
Making QR Code In Java
Using Barcode generation for Eclipse BIRT Control to generate, create QR image in BIRT applications.
www.OnBarcode.com
Recognizing Code 39 Full ASCII In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
When we talk about messaging in the Java EE context, what we really mean is the process of loosely coupled, asynchronous communication between system components. Most communication between components is synchronous, such as simple method invocation or Java RMI. In both cases, the invoker and the invocation target have to be present for the communication to succeed. Synchronous communication also means that the invoker must wait for the target to complete the request for service before proceeding. As an analogy, you re communicating synchronously when you (the invoker) call and talk to someone over the phone. But what if the person (the invocation target) isn t available If possible, you leave a voicemail message. The voicemail service makes the communication asynchronous by storing your message so that the receiver can listen to it later and respond. Message-oriented middleware (MOM) enables messaging in much the same way that a voicemail service does by acting as the middleman between a message sender and the receiver so that they don t have to be available simultaneously. In this section, we briefly introduce MOM, show how messaging is used in our ActionBazaar application, and examine popular messaging models.
Make Barcode In C#
Using Barcode printer for Visual Studio .NET Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
UCC - 12 Decoder In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Messaging and developing MDBs
Barcode Creator In Java
Using Barcode drawer for Android Control to generate, create Barcode image in Android applications.
www.OnBarcode.com
Generate UPC-A Supplement 5 In Java
Using Barcode creation for BIRT reports Control to generate, create UPC A image in Eclipse BIRT applications.
www.OnBarcode.com
Figure 4.1 Basic MOM message flow. When the producer sends a message to the software, it is stored immediately and later collected by the consumer. Looks a lot like e-mail, doesn t it
Creating Code 3 Of 9 In Visual C#.NET
Using Barcode encoder for .NET framework Control to generate, create Code 3/9 image in .NET framework applications.
www.OnBarcode.com
Decoding UPC-A Supplement 5 In Visual Studio .NET
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
4.1.1 Message-oriented middleware
Making EAN13 In None
Using Barcode printer for Software Control to generate, create EAN13 image in Software applications.
www.OnBarcode.com
Decode Barcode In Visual Basic .NET
Using Barcode reader for .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Message-oriented middleware is software that enables asynchronous messages between system components. When a message is sent, the software stores the message in a location specified by the sender and acknowledges receipt immediately. The message sender is called a producer, and the location where the message is stored is called a destination. At a later point in time, any software component interested in messages at that particular destination can retrieve currently stored messages. The software components receiving the messages are called the message consumers. Figure 4.1 depicts the various components of MOM. MOM is not a new concept by any means. MOM products include IBM WebSphere MQ, TIBCO Rendezvous, SonicMQ, ActiveMQ, and Oracle Advanced Queuing. To flesh out messaging concepts a bit more, let s explore a problem in the ActionBazaar application. We ll continue working on this problem as we progress through the chapter.
4.1.2 Messaging in ActionBazaar
As an additional source of revenue, ActionBazaar will list items for bid when the company is able to find good bulk deals through its extensive purchasing network. These items, displayed on the site as ActionBazaar Specials, come with complete satisfaction guarantees. ActionBazaar automatically ships these items from their warehouse to winning bidders as soon as they order them. When
Copyright © OnBarcode.com . All rights reserved.