barcode font vb.net The environment naming context and resolving global JNDI names in Java

Printing Data Matrix 2d barcode in Java The environment naming context and resolving global JNDI names

The environment naming context and resolving global JNDI names
Data Matrix ECC200 Encoder In Java
Using Barcode encoder for Java Control to generate, create Data Matrix ECC200 image in Java applications.
www.OnBarcode.com
ECC200 Decoder In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
If you know how JNDI references worked in EJB 2, you re familiar with the environment naming context (ENC). ENC allows portability of the application without having to depend on global JNDI names. Global JNDI names for resources differ between application server implementations, and ENC allows you to use a JNDI location that starts with java:comp/env/ instead of hard-coding the actual global JNDI name. EJB 3 essentially assumes that all JNDI names used in code are local references and automatically prepends names with the java: comp/env/ prefix.
Make UPC - 13 In Java
Using Barcode drawer for Java Control to generate, create EAN 13 image in Java applications.
www.OnBarcode.com
Barcode Printer In Java
Using Barcode generator for Java Control to generate, create Barcode image in Java applications.
www.OnBarcode.com
Learning advanced EJB concepts
Barcode Creator In Java
Using Barcode encoder for Java Control to generate, create Barcode image in Java applications.
www.OnBarcode.com
PDF 417 Encoder In Java
Using Barcode printer for Java Control to generate, create PDF 417 image in Java applications.
www.OnBarcode.com
This automatic interpretation of EJB 3 JNDI names into local references is a nice alternative to mentioning the local ENC (java:comp/env) prefix over and over again. However, this convenience does come at a price. Since you cannot use global names with the name parameter, you have to make sure that you perform the mapping between the ENC and global JNDI names in all cases. Fortunately, many application servers will automatically resolve the ENC name to the global JNDI name if a resource with the same global JNDI name exists. For example, if you are using the Sun GlassFish or Oracle Application Server and you define a data source as shown here, the application server will automatically map the data source to the global JNDI resource bound to jdbc/ActionBazaarDS, even if you didn t explicitly map the resource:
Generate USS-128 In Java
Using Barcode creator for Java Control to generate, create UCC.EAN - 128 image in Java applications.
www.OnBarcode.com
GTIN - 12 Generation In Java
Using Barcode encoder for Java Control to generate, create UPC - E1 image in Java applications.
www.OnBarcode.com
@Resource(name="jdbc/ActionBazaarDS") private javax.jdbc.DataSource myDB;
Data Matrix Creation In Java
Using Barcode generation for Android Control to generate, create Data Matrix ECC200 image in Android applications.
www.OnBarcode.com
Data Matrix Maker In None
Using Barcode creator for Online Control to generate, create Data Matrix ECC200 image in Online applications.
www.OnBarcode.com
Moreover, application servers allow you to explicitly specify a global JNDI name using the mappedName parameter of the @Resource annotation. For example, if you re using the JBoss Application Server and you have a data source with a global JNDI name of java:/DefaultDS, you can specify the resource mapping as follows:
Barcode Generation In C#
Using Barcode maker for Visual Studio .NET Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Reading Data Matrix ECC200 In Visual C#.NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
@Resource(name="jdbc/ActionBazaarDS", mappedName="java:/DefaultDS") private javax.jdbc.DataSource myDB;
ECC200 Generator In Objective-C
Using Barcode generator for iPhone Control to generate, create ECC200 image in iPhone applications.
www.OnBarcode.com
Encoding Data Matrix 2d Barcode In Visual Studio .NET
Using Barcode drawer for Reporting Service Control to generate, create ECC200 image in Reporting Service applications.
www.OnBarcode.com
In this case, the container will look up the data source with the global JNDI name of java:/DefaultDS when the ENC java:comp/env/jdbc/ActionBazaarDS is resolved. However, remember that using the mappedName parameter makes code less portable. Therefore, we recommend you use deployment descriptors for mapping global JNDI names instead. Note that, similar to the @Resource annotation, the @EJB annotation has a mappedName parameter as well.
Reading Barcode In C#.NET
Using Barcode reader for .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Print PDF 417 In None
Using Barcode creation for Online Control to generate, create PDF-417 2d barcode image in Online applications.
www.OnBarcode.com
Behind the scenes, the container resolves the JNDI references to the resources and binds the resource to the ENC during deployment. If the resource is not found during injection, the container throws a runtime exception and the bean becomes unusable. Beyond JNDI name mapping, the @Resource annotation is meant to be a lot more flexible when it needs to be than what is apparent in our deliberately straightforward data source injection example. To illustrate some of these robust features, let s take a look at the definition for the annotation:
Printing GTIN - 12 In Objective-C
Using Barcode printer for iPad Control to generate, create GS1 - 12 image in iPad applications.
www.OnBarcode.com
Barcode Scanner In .NET
Using Barcode reader for VS .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Accessing resources using DI and JNDI
Draw UPC A In Visual Studio .NET
Using Barcode printer for VS .NET Control to generate, create GS1 - 12 image in VS .NET applications.
www.OnBarcode.com
Create Code 3 Of 9 In Visual Studio .NET
Using Barcode creator for .NET Control to generate, create Code 3 of 9 image in VS .NET applications.
www.OnBarcode.com
@Target({TYPE, METHOD, FIELD}) @Retention(RUNTIME) public @interface Resource { public enum AuthenticationType { CONTAINER, APPLICATION } String name() default ""; Class type() default Object.class; AuthenticationType authenticationType() default AuthenticationType.CONTAINER; boolean shareable() default true; String mappedName() default ""; description() default ""; }
The first point you should note from the definition of the @Resource annotation is that it is not limited to being applied to instance variables. As the @Target value indicates, it can be applied to setter methods, and even classes. Setter vs. field injection Other than field injection, setter injection is the most commonly used option for injection. To see how it works, let s transform our data source example to use setter injection:
@Stateless public class PlaceBidBean implements PlaceBid { ... private DataSource dataSource; ... @Resource(name="jdbc/actionBazaarDB") public void setDataSource(DataSource dataSource) { this.dataSource = dataSource; }
As you can see, setter injection relies on JavaBeans property-naming conventions. In case you are unfamiliar with them, the conventions dictate that the instance variables of an object should always be private so that they cannot be externally accessible. Instead, an instance variable named XX should have corresponding nonprivate methods named getXX and setXX that allow it to be accessed and set externally. We ve seen how the setter for the PlaceBidBean dataSource variable looks. The getter could look like this:
public DataSource getDataSource() { return dataSource; }
Copyright © OnBarcode.com . All rights reserved.