Resin organizes resources and classloaders into nested environments. Each environment context merges its own configuration with configuration inherited from the parent environment. Each environment context: server, host, web-app, etc. may be configured with any of the environment configuration tags.

Classloaders

class-loader

Adds dynamic classloaders to the current environment.

Each environment (<server>, <host>, <web-app>) etc, can add dynamic classloaders. The environment will inherit the parent classloaders. Each <class-loader> is comprised of several implementing loader items: library-loader for WEB-INF/lib, compiling-loader for WEB-INF/classes, even make-loader for more complex auto-compilation.

<web-app xmlns="http://caucho.com/ns/resin">
  <prologue>
    <class-loader>
      <compiling-loader path="WEB-INF/classes"/>

      <library-loader path="WEB-INF/lib"/>
    </class-loader>
  </prologue>
</web-app>

compiling-loader

Configures an auto-compiling WEB-INF/classes-style class loader.

The compiling-loader will automatically compile Java code into .class files loading them.

library-loader

Configures a jar library, WEB-INF/lib-style class loader.

The library-loader will add jar files in its path to the current classpath. Jar files are recognized wihen they have a filename extension of .jar or .zip.

See com.caucho.loader.DirectoryLoader.

tree-loader

Configures a jar library, WEB-INF/lib-style class loader similar to library-loader, but will also find .jar and .zip files in subdirectories.

See com.caucho.loader.TreeLoader.

make-loader

Configures a custom make-style loader.

servlet-hack

Use of servlet-hack is discouraged. Using servlet-hack violates the JDK's classloader delegation model and can produce surprising ClassCastExceptions.

servlet-hack reverses the normal class loader order. Instead of parent classloaders having priority, child classloaders have priority.

simple-loader

Configures a simple classes-style class loader.

.class files in the specified directory will be loaded without any special compilation steps (in contrast with compiling-loader.)

Clustering

cluster

Configures a cluster of Resin servers for load balancing and sharing state information.

Each cluster is a collection of Resin servers. The servers will share session information if the sessions are configured for <cluster-store>.

Each environment context is associated with a single cluster. If no cluster is defined for the context, it defaults to the parent cluster.

Normally, the cluster will be configured in the <server> context, although a cluster could be defined in a web-app for finer load-balancing. Only clusters defined in the <server> context are used for listening to ports. Other clusters are only for outgoing load balancing.

<resin xmlns="http://caucho.com/ns/resin">
<server>
  <cluster>
    <srun id='a' port='6810'/>
    <srun id='b' port='6811'/>
  </cluster>
  ...

cluster-definition

Defines a cluster for later use by cluster-ref.

Resources

connector

Configures a JCA resource adapter and its associated connection factories.

The resource adapter/connector will have been added as a rar file (see resource-deploy. The <connector> configures that rar resource.

<connector connector-name="Test Resource">
  <connection-factory jndi-name="eis/test">
    <init>
      <value>b</value>
    </init>
  </connection-factory>
</connector>

element connector {
  connector-name { string }

  & resource-adapter?

  & connection-factory*
}

element connection-factory {
  jndi-name,

  type?,

  element init { any }?
}

element resource-adapter {
  jndi-name,

  element init { any }?
}

database

Defines a database resource.

The database configuration section has more details on the configuration. A code pattern for using databases is in a DataSource tutorial.

<database jndi-name='jdbc/test_mysql'>
  <driver 
    type="com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource">
    <url>jdbc:mysql://localhost:3306/test</url>
    <user></user>
    <password></password>
  </driver>
</database>

ejb-server

Configures an EJB/CMP server. See the CMP configuration for more details.

env-entry

Configures a JNDI scalar value for JNDI-based application configuration.

Some application beans prefer to retrieve configuration data from JNDI, including String, Integer, and Double constants. env-entry configures that data in the current context. As with other Resin configuration, the value can use JSP-EL expressions.

The example configuration stores a string in java:comp/env/greeting. Following the J2EE spec, the env-entry-name is relative to java:comp/env. If the env-entry is in the <host> context, it will be visible to all web-apps in the host.

<env-entry>
  <env-entry-name>greeting</env-entry-name>
  <env-entry-type>java.lang.String</env-entry-type>
  <env-entry-value>Hello, World</env-entry-value>
</env-entry>

The following servlet fragment is a typical use in a servlet. The servlet only looks up the variable once and stores it for later use.

import java.io.*;
import javax.naming.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class TestServlet extends HttpServlet {
  private String greeting;

  public void init()
    throws ServletException
  {
    try {
      Context env = 
        (Context) new InitialContext().lookup("java:comp/env");
      greeting = (String) env.lookup("greeting");
    } catch (NamingException e) {
      throw new ServletException(e);
    }
  }

  ...
}

element env-entry {
  (attribute env-entry-name { string } | 
   element env-entry-name { string }),

  (attribute env-entry-type { string } | 
   element env-entry-type { string }),

  (attribute env-entry-value { string } | 
   element env-entry-value { string })
}

jndi-link

Links a foreign JNDI contexts or JNDI object.

Resin's JNDI can link to foreign JNDI contexts. For example, third-party EJB servers will often expose their EJB beans through a JNDI context. jndi-link will create the appropriate InitialContextFactory, configure it, and lookup the foreign JNDI objects.

<jndi-link>
  <jndi-name>java:comp/env/ejb/traderHome</jndi-name>
  <factory>weblogic.jndi.WLInitialContextFactory</factory>
  <init-param java.naming.provider.url="t3://localhost:7001"/>
  <foreign-name>statelessSession/TraderHome</foreign-name>
</jndi-link>

<jndi-link>
  <jndi-name>java:comp/env/ejb/MyBean</jndi-name>
  <foreign-name>/SampleBean</foreign-name>
</jndi-link>

reference

Configures a JNDI ObjectFactory.

JNDI ObjectFactories are used to create objects from JNDI references. The <reference> tag configures the ObjectFactory and stores it in JNDI.

<reference>
  <jndi-name>hessian/hello</jndi-name>
  <factory>com.caucho.hessian.client.HessianProxyFactory</factory>
  <init url="http://localhost:8080/ejb/hello"/>
        type="test.HelloHome"/>
</reference>

resource

Configures a custom bean resource and stores in JNDI.

Resources are beans stored in JNDI. The resources can be created from any Java class that conforms to the bean conventions. Configuration of the resource is in the <init> section. Field values may use JSP-EL expressions as well as constant strings or even complex sub-beans.

<resource jndi-name="env/test">
  <type>test.MyBean</type>
  <init>
    <greeting>Hello</greeting>
    <server>${'${'}serverId}</server>
    <sub-bean>
      <value>${'${2'} + 2}</value>
    </sub-bean>
  </init>
</resource>

r_listener-Resource = element listener {
  r_mbean-name,

  r_handback*
}

r_resource = element resource {
  (r_jndi-name?

  & r_mbean-name?

  & r_mbean-interface?),

  (r_type,

  r_arg*)?,

  (r_init*

  & r_listener-Resource*)
}

resource-deploy

Defines a deployment directory for .rar files.

Connectors and resources defined in .rar files must be deployed before they can be configured by connector. The <resource-deploy> tag specifies the directory for that deployment.

<host>
  <resource-deploy path="deploy"/>

  ...
</host>

element resource-deploy {
  (attribute path { string } | element path { string })

  & (attribute expand-path { string } | 
         element expand-path { string })?
}

resource-ref

Declares that the application needs a resouce configuration.

resource-ref is not directly used by Resin. It's a servlet configuration item intended to tell GUI tools which resources need configuration. Resource configuration in Resin uses the resource, reference, database, and ejb-server tags.

For backwards compatibility, Resin 2.1-style configuration files may still use resource-ref to configure resources, but it's recommended to convert the configuration.

Logging

log

Configures JDK 1.4 java.util.logger logging.

The log configuration describes log in detail.

stderr-log

Configures the destination for System.err.

The log configuration describes stderr-log in detail.

stdout-log

Configures the destination for System.out.

The log configuration describes stderr-log in detail.

Authenticator

authenticator

Configures an authentication resource for the current context.

Resin's servlet authentication uses an authentication resource to validate user login and to provide single-signon capability. The authenticator is configured in the environment context where it is shared. So an authenticator configured in the web-app only applies to the web-app, but an authenticator configured in the host will apply to all hosts.

The authenticator class is selected with the type attribute. It can be any custom class extending com.caucho.server.security.AbstractAuthenticator. Configuration of the authenticator uses bean-style configuration in the <init> tag.

Miscellaneous

system-property

Sets a Java system property. The effect is the same as if you had called java.lang.System before starting Resin.

<resin>
  <system-property foo="bar"/>
</resin>

javac

Configures the Java compiler for automatically compiled files.

The javac configuration is used for JSP, XSL, EJB and compiling-loader configuration.

dependency

Configures a path as a file which should force a reload when changed, like web.xml and resin.xml.

<web-app xmlns="http://caucho.com/ns/resin">
  <dependency path="WEB-INF/struts-config.xml"/>
  ...
</web-app>

dependency-check-interval

Configures how often the environment context should be checked for changes.

Resin automatically checks each environment for updates, generally class or configuration updates. Because these checks can take a considerable amount of time, deployment servers should use high values like 60s or more while development machines will want low values like 2s.

The interval defaults to the parent's interval. So the web-app will default to the host's value.

character-encoding

Specifies the default character encoding for the environment.

<web-app id='/'>
  <character-encoding>shift_jis</character-encoding>
  ...

</web-app>

case-insensitive

Specifies whether the environment context is case sensitive or insensitive.

Because some operating systems are case-insensitive, it is important for security reasons for Resin to behave differently for case-sensitive and case-insensitive directories. For example, when case-insensitive is true, url-patterns will match in a case-insensitive manner, so TEST.JSP will work like test.jsp.

temp-dir

Application temp directory. This is the path used in javax.servlet.context.tempdir.

work-dir

Application work directory. This is the directory used for generated code like JSP, XSL and EJB classes.