Download Reserved namespaces in J2EE

JNDI
Big picture
Reserved namespaces in J2EE
Prefix
java:comp/env
Description
Environment
variables
java:comp/env/ejb
EJB references
java:comp/env/jdbc
JDBC DataSource
reference
Declaration example
<env-entry>
<env-entry-name>myValue</env-entryname>>
<env-entry-value>10</env-entry-value>
<env-entry-type>java.lang.String</enventry-type>
</env-entry>
<ejb-ref>
<ejb-ref-name>ejb/EmplRecord</ejb-refname>
<ejb-ref-type>Entity</ejb-ref-type>
<home>com.wombat.empl.EmployeeRecordHo
me</home>
<remote>com.wombat.empl.EmployeeRecord<
/remote>
</ejb-ref>
Возвращаемый объект имеет тип
javax.sql.DataSource.
<resource-ref>
<res-ref-name>jdbc/EmployeeAppDB</res-refname>
<res-type>javax.sql.DataSource</res-type>
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java:comp/env/jms
JMS connection
factories
java:comp/env/url
URL connection
factories
JavaMail API
connection
factories
java:comp/env/mail
<res-auth>Container</res-auth>
</resource-ref>
Возможные классы для возвращаемых
объектов:
 javax.jms.QueueConnectionFactory
 javax.jms.TopicConnectionFactory
 javax.jms.ConnectionFactory
java.net.URL
javax.mail.Session
<resource-ref>
<res-ref-name>mail/Session</res-ref-name>
<res-type>javax.mail.Session</res-type>
<res-auth>Container</res-auth>
</resource-ref>
javax.transaction.UserTransaction
java:comp/UserTransaction JTA transaction
context
java:comp/ORB
CORBA ORB
references
Code examples
JNDI call in scope of J2EE container:
Context initCtx = new InitialContext();
Context envCtx = (Context) initCtx.lookup("java:comp/env");
Session session = (Session) envCtx.lookup("mail/Session");
Custom factory:
Hashtable hash = new Hashtable();
hash.put(Context.INITIAL_CONTEXT_FACTORY,
"com.siberon.ws.config.jndi.ConfigContextFactory");
hash.put("config.input.stream", new FileInputStream("test.txt"));
hash.put("config.validate", "true");
Context context = new InitialContext(hash);
Struts
Struts servlet registration
<servlet>
<servlet-name>
interface
</servlet-name>
<servlet-class>
org.apache.struts.action.ActionServlet
</servlet-class>
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<!-- *.do mapping must be last mapping because Struts uses last matched mapping -->
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<servlet-mapping>
<servlet-name>
interface
</servlet-name>
<url-pattern>
*.do
</url-pattern>
</servlet-mapping>
<!-- Struts Tag Library Descriptors -->
<taglib>
<taglib-uri>struts-bean.tld</taglib-uri>
<taglib-location>/WEB-INF/tld/struts-bean.tld</taglib-location>
</taglib>
<taglib>
<taglib-uri>struts-html.tld</taglib-uri>
<taglib-location>/WEB-INF/tld/struts-html.tld</taglib-location>
</taglib>
<taglib>
<taglib-uri>struts-logic.tld</taglib-uri>
<taglib-location>/WEB-INF/tld/struts-logic.tld</taglib-location>
</taglib>
<taglib>
<taglib-uri>struts-tiles.tld</taglib-uri>
<taglib-location>/WEB-INF/tld/struts-tiles.tld</taglib-location>
</taglib>
Configuration file example
Here's a simple Struts configuration (struts-config.xml) for a login workflow:
<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE struts-config PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration
1.2//EN"
"http://struts.apache.org/dtds/struts-config_1_2.dtd">
<struts-config>
<form-beans>
<form-bean
name="logonForm"
type="app.LogonForm"/>
</form-beans>
<action-mappings>
<action
path="/Welcome"
forward="/pages/Welcome.jsp"/>
<action
path="/Logon"
forward="/pages/Logon.jsp"/>
<action
path="/LogonSubmit"
type="app.LogonAction"
name="logonForm"
scope="request"
validate="true"
input="/pages/Logon.jsp">
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<forward
name="success"
path="/pages/Welcome.jsp"/>
<forward
name="failure"
path="/pages/Logon.jsp"/>
</action>
<action
path="/Logoff"
type="app.LogoffAction">
<forward
name="success"
path="/pages/Logoff.jsp"/>
</action>
</action-mappings>
<message-resources parameter="resources.application"/>
</struts-config>
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