Code generation with XDoclet in Java

Making PDF417 in Java Code generation with XDoclet

Finally, the additional subtasks must be specified in the <ejbdoclet/> task itself. As you can see in the recipe, we add tasks to generate all four interfaces for the beans. Indeed, all four will be generated because we also specified the viewtype as both. In addition, by default XDoclet will add a component name and JNDI name for both the local home and home interfaces as a public final static member variable. You can use the variable to make your client code more maintainable. By default, the names correspond to the fully qualified name of the bean class (using / instead of .). Rather than show all four generated interfaces for each bean, we just show the local interfaces for each. For the session bean, the getName() and setName() methods will be in the local and remote interfaces. The session bean s home and local home interfaces will contain a create() method. Listing 2.4 contains the session bean s generated entire remote interface (comments and all).

/* * Generated by XDoclet - Do not edit! */ package ch2; /** * Remote interface for ch2.User. */ public interface User extends javax.ejb.EJBObject { public java.lang.String getName( ) throws java.rmi.RemoteException; public void setName( java.lang.String value ) throws java.rmi.RemoteException; }

The entity bean s home and local home interfaces will contain a findByPrimaryKey() method. Its remote and local interface will contain getFirstName(), setFirstName(), getLastName(), setLastName(), and getName(). Listing 2.5 contains the entity bean s generated remote interface .

/* * Generated by XDoclet - Do not edit! */ package ch2; /** * Remote interface for ch2.Data. */ public interface Data extends javax.ejb.EJBObject { public void getAllData( ) throws java.rmi.RemoteException; public java.lang.String getBigData( ) throws java.rmi.RemoteException; public java.lang.String getSmallData( throws java.rmi.RemoteException; )

public void setBigData( java.lang.String data ) throws java.rmi.RemoteException; public void setSmallData( java.lang.String data ) throws java.rmi.RemoteException; }

2.2 Adding and customizing the JNDI name for the home interface 2.5 Generating a primary key class 2.11 Generating finder methods for entity home interfaces

You can use XDoclet to add a public static final member variable to the home interfaces that it generates to store the JNDI name of the bean. Without customization, it provides a default value for this name. By specifying the JNDI name in the home interface, you can modify it without changing your bean lookup code.

Use the recipe shown in recipe 2.1 (listing 2.4) to generate the home interface. However, change the class-level JavaDoc to look like the following and specify the JNDI name (the changes are shown in bold):

/** * @ejb.bean type="Stateful" * jndi-name="ejb/UserBean" * local-jndi-name="ejb/UserBeanLocal" * view-type="both" */ public class UserBean implements SessionBean {

By including the JNDI lookup name as a public static final member variable in the home interface, you give your code a permanent, safe way of discovering the JNDI name for EJB lookup. Using this method, you don t have to hardcode a name in the lookup implementation. The resulting home interface has the following lines added to it:

public static final String COMP_NAME="comp/env/ejb/ch2/User"; public static final String JNDI_NAME="ejb/UserBean";

The resulting local home interface contains a different name (as specified in the bean source):

public static final String COMP_NAME="java:comp/env/ejb/ch2/UserLocal"; public static final String JNDI_NAME="ejb/UserBeanLocal";

Without customization, XDoclet will enter names using the package name of the bean class. For instance, the UserBean JNDI name would have been ch2/UserBean.

When looking up an EJB home interface via JNDI, you normally would use code similar to the following:

InitialContext ctx = new InitialContext(); UserHome home = (UserHome) ctx.lookup( "ejb/UserBean" );

By adding the JNDI name to the home interface, your code can change to something like this:

InitialContext ctx = new InitialContext(); UserHome home = (UserHome) ctx.lookup( UserHome.JNDI_NAME );