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Webdoclet Tags
Let's take a moment and discuss the tags we've used in our servlet example shown in the previous listing. The first tag in our example is @web.servlet. This tag is designed to create the class-level <servlet> element within the deployment descriptor. For our servlet, we've defined the name, display-name, and load-on-startup attribute of the tag:@web.servlet name="SimpleServlet"
display-name="Simple Servlet"
1oad-on-startup=" Y'
The result of the tag once processed by XDoclet will be:
<servlet>
<servlet-name>SimpleServlet</servlet-name>
<display-name>Simple Servlet</display-name>
<servlet-class>example.SimpleServlet</servlet-class>
<load-on-startup>1</load-on-start up>
</servlet>
The attributes available for the @web.servlet tag are shown in the following table.
Attribute | Description | Required |
|---|---|---|
Name | Servlet name | T |
display-name | Servlet display name | F |
Icon | Servlet icon | F |
Description | Servlet description | F |
load-on-startup | The load order of this servlet – number where 1 is first | F |
run-as | The role to run this servlet as | F |
The next two webdoclet tags in our example use the @web-servlet-init-param to create the init-param tags within the deployment descriptor:
@web-servlet-init-param name="table" value="production"
@web-servlet-init-param name="account" value="accounts"
The result of these tags will be:
<servlet>
<servlet-name>
...
<init-param>
<param-name>table</param-name>
<param-value>production</param-value>
</init-param>
<init-param>
<param-name>table</param-name>
<param-value>production</param-value>
</init-param>
</servlet>
The attributes available for the @web.servlet-init-param tag are shown in the following table.
Attribute | Description | Required |
|---|---|---|
Name | Parameter value | T |
Value | Parameter value | F |
Icon | Servlet icon | F |
Description | Servlet description | F |
After creating the necessary parameters for the servlet, we can define any J2EE resources needed by the servlet. In our example servlet, we will be accessing a database to pull rows that will be displayed to the user based on the init-params:
@web.resource-ref description="database connection"
name=' jdbc/dbconnection"
type="javax.sgl.DataSource"
auth="Container"
The result of this webdoclet tag will be:
<resource-ref>
<description>JDBC Connection</description>
<res-ref-name>jdbc/dbconnection</res-ref-name>
<res-type>javax.sg1.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
The attributes available for the @web.resource-ref tag are shown in the following table.
Attribute | Description | Required |
|---|---|---|
Name | Resource name | T |
Type | Resource type | T |
Auth | Resource authentication: Application or Container | T |
Description | Resource description | F |
Scope | Resource scope: Shareable Unshareable | F |
Jndi-name | Resource Jndi-name | F |
Finally, we can apply the necessary pattern-matching mappings necessary for launching the servlet. This is accomplished using the @web.servlet-mapping tag:
@web.servlet-mapping url-pattern="/Example/*"
@web.servlet-mapping url-pattern="/SimpleServlet"
These two tags will define the following mappings in our deployment descriptor:
<servlet-mapping>
<servlet-name>SimpleServlet</servlet-name>
<url-pattern >/Example/* </url-pattern >
</servlet-mapping>
<servlet-mapping>
<servlet-name>SimpleServlet</servlet-name>
<url-pattern>SimpleServlet</url-pattem>
</servlet-mapping>
The attribute available in the @web.servlet-mapping tag is shown in the following table.
Attribute | Description | Required |
|---|---|---|
url-pattern | Pattern to match | T |
