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Assembling and Configuring Web Applications

web.xml Deployment Descriptor Elements

This following sections describe the deployment descriptor elements defined in the web.xml file. The root element for web.xml is <web-app>. The following elements are defined within the <web-app> element:

- icon

- display-name

- description

- distributable

- context-param

- filter

- filter-mapping

- listener

- servlet

- servlet-mapping

- session-config

- mime-mapping

- welcome-file-list

- error-page

- taglib

- resource-env-ref

- resource-ref

- security-constraint

- login-config

- security-role

- env-entry

- ejb-ref

- ejb-local-ref

icon

The icon element specifies the location within the Web Application for a small and large image used to represent the Web Application in a GUI tool. (The servlet element also has an element called the icon element, used to supply an icon to represent a servlet in a GUI tool.)

This element is not currently used by WebLogic Server.

The following table describes the elements you can define within an icon element.

Element | Required/ Optional | Description
--- | --- | ---
<small-icon> | Optional | Location for a small (16x16 pixel) .gif or .jpg image used to represent the Web Application in a GUI tool. Currently, this is not used by WebLogic Server.
<large-icon> | Optional | Location for a large (32x32 pixel) .gif or .jpg image used to represent the Web Application in a GUI tool. Currently, this element is not used by WebLogic Server.

display-name

The optional display-name element specifies the Web Application display name, a short name that can be displayed by GUI tools.

Element | Required/ Optional | Description
<display-name> | Optional | Currently, this element is not used by WebLogic Server.

description

The optional description element provides descriptive text about the Web Application.

Element | Required/ Optional | Description
<description> | Optional | Currently, this element is not used by WebLogic Server.

distributable

The distributable element is not used by WebLogic Server.

Element | Required/ Optional | Description
<distributable> | Optional | Currently, this element is not used by WebLogic Server.

context-param

The optional context-param element declares a Web Application's servlet context initialization parameters. You set each context-param within a single context-param element, using <param-name> and <param-value> elements. You can access these parameters in your code using the javax.servlet.ServletContext.getInitParameter() and javax.servlet.ServletContext.getInitParameterNames() methods.

The following table describes the elements you can define within a context-param element.

Element | Required/ Optional | Description
--- | --- | ---
weblogic.httpd. clientCertProxy | optional | This attribute specifies that certs from clients of the web application are provided in the special WL-Proxy-Client-Cert header sent by a proxy plug-in or HttpClusterServlet. This setting is useful if user authentication is performed on a proxy server—setting clientCertProxy causes the proxy server to pass on the certs to the cluster in a special header, WL-Proxy-Client-Cert. A WL-Proxy-Client-Cert header could be provided by any client with access to WebLogic Server. WebLogic Server takes the certificate information from that header, trusting that is came from a secure source (the plug-in) and uses that information to authenticate the user. Forthis reason, if you set clientCertProxy, use a connection filter to ensure that WebLogic Server accepts connections only from the machine on which the plug-in is running. See Using Network Connection Filters in Programming WebLogic Security. In addition to setting this attribute for an individual web application, you can define this attribute: for all web applications hosted by a server instance, on the Server-->Configuration-->General page in the Administration Console for all web applications hosted by server instances in a cluster, on the Cluster-->Configuration-->General page.

filter

The filter element defines a filter class and its initialization parameters.

The following table describes the elements you can define within a servlet element.

Element | Required/ Optional | Description
--- | --- | ---
<icon> | Optional | Specifies the location within the Web Application for a small and large image used to represent the filter in a GUI tool. Contains a small-icon and large-icon element. Currently, this element is not used by WebLogic Server.
<filter-name> | Required | Defines the name of the filter, used to reference the filter definition elsewhere in the deployment descriptor.
<display-name> | Optional | A short name intended to be displayed by GUI tools.
<description> | Optional | A text description of the filter.
<filter-class> | Required | The fully-qualified class name of the filter.
<init-param> | Optional | Contains a name/value pair as an initialization parameter of the filter. Use a separate set of <init-param> tags for each parameter.

filter-mapping

The following table describes the elements you can define within a filter-mapping element.

Element | Required/ Optional | Description
--- | --- | ---
<filter-name> | Required | The name of the filter to which you are mapping a URL pattern or servlet. This name corresponds to the name assigned in the <filter> element with the <filter-name> element.
<url-pattern> | Required - or map by <servlet> | Describes a pattern used to resolve URLs. The portion of the URL after the http://host:port + ContextPath is compared to the <url-pattern> by WebLogic Server. If the patterns match, the filter mapped in this element is called. Example patterns: /soda/grape/* /foo/* /contents *.foo The URL must follow the rules specified in the Servlet 2.3 Specification.
<servlet> | Required - or map by <url-pattern> | The name of a servlet which, if called, causes this filter to execute.

listener

Define an application listener using the listener element.

Element | Required/ Optional | Description
--- | --- | ---
<listener-class> | Optional | Name of the class that responds to a Web Application event.

For more information, see Configuring an Event Listener.

servlet

The servlet element contains the declarative data of a servlet.

If a jsp-file is specified and the <load-on-startup> element is present, then the JSP is precompiled and loaded when WebLogic Server starts.

The following table describes the elements you can define within a servlet element.

Element | Required/ Optional | Description
--- | --- | ---
<icon> | Optional | Location within the Web Application for a small and large image used to represent the servlet in a GUI tool. Contains a small-icon and large-icon element. Currently, this element is not used by WebLogic Server.
<servlet-name> | Required | Defines the canonical name of the servlet, used to reference the servlet definition elsewhere in the deployment descriptor.
<display-name> | Optional | A short name intended to be displayed by GUI tools.
<description> | Optional | A text description of the servlet.
<servlet-class> | Required (or use <jsp- file>) | The fully-qualified class name of the servlet. Use only one of either the <servlet-class> tags or <jsp-file> tags in your servlet body.
<jsp-file> | Required (or use <servlet- class>) | The full path to a JSP file within the Web Application, relative to the Web Application root directory. Use only one of either the <servlet-class> tags or <jsp-file> tags in your servlet body.
<init-param> | Optional | Contains a name/value pair as an initialization parameter of the servlet. Use a separate set of <init-param> tags for each parameter.
<load-on-startup> | Optional | WebLogic Server initializes this servlet when WebLogic Server starts up. The optional contents of this element must be a positive integer indicating the order in which the servlet should be loaded. Lower integers are loaded before higher integers. If no value is specified, or if the value specified is not a positive integer, WebLogic Server can load the servlet in any order in the startup sequence.
<security-role- ref> | Optional | Used to link a security role name defined by <security-role> to an alternative role name that is hard coded in the servlet logic. This extra layer of abstraction allows the servlet to be configured at deployment without changing servlet code.
<run-as> |  | Specifies the run-as identity to be used for the execution of the Web application. It contains an optional description and the name of a security role. Subelements of the run-as element are: description—(optional) description of the run-as identity role-name—this can be a role name that is mapped to a principal name in weblogic.xml. If it is mapped to multiple principal names, the first one is used. Otherwise, the role name can be a valid principal-name (user name) in the system.

icon

This is an element within the servlet.

The icon element specifies the location within the Web Application for small and large images used to represent the servlet in a GUI tool.

The following table describes the elements you can define within an icon element.

Element | Required/ Optional | Description
--- | --- | ---
<small-icon> | Optional | Specifies the location within the Web Application for a small (16x16 pixel) .gif or .jpg image used to represent the servlet in a GUI tool. Currently, this element is not used by WebLogic Server.
<large-icon> | Optional | Specifies the location within the Web Application for a small (32x32 pixel) .gif or .jpg image used to represent the servlet in a GUI tool. Currently, this element is not used by WebLogic Server.

init-param

This is an element within the servlet.

The optional init-param element contains a name/value pair as an initialization parameter of the servlet. Use a separate set of init-param tags for each parameter.

You can access these parameters with the javax.servlet.ServletConfig.getInitParameter() method.

The following table describes the elements you can define within a init-param element.

Element | Required/ Optional | Description
--- | --- | ---
<param-name> | Required | Defines the name of this parameter.
<param-value> | Required | Defines a String value for this parameter.
<description> | Optional | Text description of the initialization parameter.

WebLogic Server recognizes the special initialization parameter, wl-dispatch-policy, to assign a servlet or JSP to an available execute queue. For example, the following example assigns a servlet to use the execute threads available in an execute queue named CriticalWebApp:

>     <servlet>
>        ...
>        <init-param>
>           <param-name>wl-dispatch-policy</param-name>
>           <param-value>CriticalWebApp</param-value>
>        </init-param>
>     </servlet>

If the CriticalWebApp queue is not available, the servlet will use execute threads available in the default WebLogic Server execute queue. See Setting Thread Count for more information about configuring execute threads in WebLogic Server. See Using Execute Queues to Control Thread Usage for more information about creating and using queues.

security-role-ref

This is an element within the servlet.

The security-role-ref element links a security role name defined by <security-role> to an alternative role name that is hard-coded in the servlet logic. This extra layer of abstraction allows the servlet to be configured at deployment without changing servlet code.

The following table describes the elements you can define within a security-role-ref element.

Element | Required/ Optional | Description
--- | --- | ---
<description> | Optional | Text description of the role.
<role-name> | Required | Defines the name of the security role or principal that is used in the servlet code.
<role-link> | Required | Defines the name of the security role that is defined in a <security-role> element later in the deployment descriptor.

servlet-mapping

The servlet-mapping element defines a mapping between a servlet and a URL pattern.

The following table describes the elements you can define within a servlet-mapping element.

Element | Required/ Optional | Description
--- | --- | ---
<servlet-name> | Required | The name of the servlet to which you are mapping a URL pattern. This name corresponds to the name you assigned a servlet in a <servlet> declaration tag.
<url-pattern> | Required | Describes a pattern used to resolve URLs. The portion of the URL after the http://host:port + WebAppName is compared to the <url-pattern> by WebLogic Server. If the patterns match, the servlet mapped in this element will be called. Example patterns: /soda/grape/* /foo/* /contents *.foo The URL must follow the rules specified in the Servlet 2.3 Specification. For additional examples of servlet mapping, see Servlet Mapping.

session-config

The session-config element defines the session parameters for this Web Application.

The following table describes the element you can define within a session-config element.

Element | Required/ Optional | Description
--- | --- | ---
<session-timeout> | Optional | The number of minutes after which sessions in this Web Application expire. The value set in this element overrides the value set in the TimeoutSecs parameter of the <session-descriptor> element in the WebLogic-specific deployment descriptor weblogic.xml, unless one of the special values listed here is entered. Default value: -2 Maximum value: Integer.MAX_VALUE ÷ 60 Special values: -2 = Use the value set by TimeoutSecs in <session-descriptor> element of weblogic.xml -1 = Sessions do not timeout. The value set in <session-descriptor> element of weblogic.xml is ignored. For more information, see jsp-descriptor.

mime-mapping

The mime-mapping element defines a mapping between an extension and a mime type.

The following table describes the elements you can define within a mime-mapping element.

Element | Required/ Optional | Description
--- | --- | ---
<extension> | Required | A string describing an extension, for example: txt.
<mime-type> | Required | A string describing the defined mime type, for example: text/plain.

welcome-file-list

The optional welcome-file-list element contains an ordered list of welcome-file elements.

When the URL request is a directory name, WebLogic Server serves the first file specified in this element. If that file is not found, the server then tries the next file in the list.

For more information, see Configuring Welcome Pagesand How WebLogic Server Resolves HTTP Requests.

The following table describes the element you can define within a welcome-file-list element.

Element | Required/ Optional | Description
--- | --- | ---
<welcome-file> | Optional | File name to use as a default welcome file, such as index.html

error-page

The optional error-page element specifies a mapping between an error code or exception type to the path of a resource in the Web Application.

When an error occurs—while WebLogic Server is responding to an HTTP request, or as a result of a Java exception—WebLogic Server returns an HTML page that displays either the HTTP error code or a page containing the Java error message. You can define your own HTML page to be displayed in place of these default error pages or in response to a Java exception.

For more information, see Customizing HTTP Error Responses and How WebLogic Server Resolves HTTP Requests.

The following table describes the elements you can define within an error-page element.

Note: Define either an <error-code> or an <exception-type> but not both.

Element | Required/ Optional | Description
--- | --- | ---
<error-code> | Optional | A valid HTTP error code, for example, 404.
<exception-type> | Optional | A fully-qualified class name of a Java exception type, for example, java.lang.string
<location> | Required | The location of the resource to display in response to the error. For example, /myErrorPg.html.

taglib

The optional taglib element describes a JSP tag library.

This element associates the location of a JSP Tag Library Descriptor (TLD) with a URI pattern. Although you can specify a TLD in your JSP that is relative to the WEB-INF directory, you can also use the <taglib> tag to configure the TLD when deploying your Web Application. Use a separate element for each TLD.

The following table describes the elements you can define within a taglib element.

Element | Required/ Optional | Description
--- | --- | ---
<taglib-location> | Required | Gives the file name of the tag library descriptor relative to the root of the Web Application. It is a good idea to store the tag library descriptor file under the WEB-INF directory so it is not publicly available over an HTTP request.
<taglib-uri> | Required | Describes a URI, relative to the location of the web.xml document, identifying a Tag Library used in the Web Application. If the URI matches the URI string used in the taglib directive on the JSP page, this taglib is used.

resource-env-ref

The resource-env-ref element contains a declaration of a Web application's reference to an administered object associated with a resource in the Web application's environment. It consists of an optional description, the resource environment reference name, and an indication of the resource environment reference type expected by the Web application code.

For example:

>     <resource-env-ref>

>         <resource-env-ref-name>jms/StockQueue</resource-env-ref-name>

>         <resource-env-ref-type>javax.jms.Queue</resource-env-ref-type>

>     </resource-env-ref>

The following table describes the elements you can define within a resource-env-ref element.

Element | Required/ Optional | Description
--- | --- | ---
<description> | Optional | Provides a description of the resource environment reference.
<resource-env-ref-name> | Required | Specifies the name of a resource environment reference; its value is the environment entry name used in the Web application code. The name is a JNDI name relative to the java:comp/env context and must be unique within a Web application.
<resource-env-ref-type> | Required | Specifies the type of a resource environment reference. It is the fully qualified name of a Java language class or interface.

resource-ref

The optional resource-ref element defines a reference lookup name to an external resource. This allows the servlet code to look up a resource by a "virtual" name that is mapped to the actual location at deployment time.

Use a separate <resource-ref> element to define each external resource name. The external resource name is mapped to the actual location name of the resource at deployment time in the WebLogic-specific deployment descriptor weblogic.xml.

The following table describes the elements you can define within a resource-ref element.

Element | Required/ Optional | Description
--- | --- | ---
<description> | Optional | A text description.
<res-ref-name> | Required | The name of the resource used in the JNDI tree. Servlets in the Web Application use this name to look up a reference to the resource.
<res-type> | Required | The Java type of the resource that corresponds to the reference name. Use the full package name of the Java type.
<res-auth> | Required | Used to control the resource sign on for security. If set to APPLICATION, indicates that the application component code performs resource sign on programmatically. If set to CONTAINER, WebLogic Server uses the security context established with the login-config element. See login-config.
<res-sharing-scope> | Optional | Specifies whether connections obtained through the given resource manager connection factory reference can be shared. Valid values: Shareable Unshareable

security-constraint

The security-constraint element defines the access privileges to a collection of resources defined by the <web-resource-collection> element.

For more information, see Configuring Security in Web Applications.

The following table describes the elements you can define within a security-constraint element.

Element | Required/ Optional | Description
--- | --- | ---
<web-resource- collection> | Required | Defines the components of the Web Application to which this security constraint is applied.
<auth-constraint> | Optional | Defines which groups or principals have access to the collection of web resources defined in this security constraint. See also auth-constraint.
<user-data- constraint> | Optional | Defines how the client should communicate with the server. See also user-data-constraint

web-resource-collection

Each <security-constraint> element must have one or more <web-resource-collection> elements. These define the area of the Web Application to which this security constraint is applied.

This is an element within the security-constraint.

The following table describes the elements you can define within a web-resource-collection element.

Element | Required/ Optional | Description
--- | --- | ---
<web-resource- name> | Required | The name of this Web resource collection.
<description> | Optional | A text description of this security constraint.
<url-pattern> | Optional | Use one or more of the <url-pattern> elements to declare to which URL patterns this security constraint applies. If you do not use at least one of these elements, this <web-resource-collection> is ignored by WebLogic Server.
<http-method> | Optional | Use one or more of the <http-method> elements to declare which HTTP methods (usually, GET or POST) are subject to the authorization constraint. If you omit the <http-method> element, the default behavior is to apply the security constraint to all HTTP methods.

auth-constraint

This is an element within the security-constraint.

The optional auth-constraint element defines which groups or principals have access to the collection of Web resources defined in this security constraint.

Note: An authorization constraint, which is defined using the <auth-constraint> tag, establishes a requirement for authentication and names the authorization roles, or security roles, permitted to perform the constrained requests. When you use the <auth-constraint> tag to define an authorization constraint, be advised of the following:

- If you define an authorization constraint that does not name any security roles, the container will not allow access to the constrained requests under any circumstances.

- If no authorization constraint applies to a request, the container must accept the request without requiring user authentication.

For more information on authorization constraints, see the Java Servlet Specification Version 2.4 specification located on the Internet at http://jcp.org/aboutJava/communityprocess/final/jsr154/index.html.

The following table describes the elements you can define within an auth-constraint element.

Element | Required/ Optional | Description
--- | --- | ---
<description> | Optional | A text description of this security constraint.
<role-name> | Optional | Defines which security roles can access resources defined in this security-constraint. Security role names are mapped to principals using the security-role-ref. See security-role-ref.

user-data-constraint

This is an element within the security-constraint.

The user-data-constraint element defines how the client should communicate with the server.

The following table describes the elements you may define within a user-data-constraint element.

Element | Required/ Optional | Description
--- | --- | ---
<description> | Optional | A text description.
<transport- guarantee> | Required | Specifies that the communication between client and server. WebLogic Server establishes a Secure Sockets Layer (SSL) connection when the user is authenticated using the INTEGRAL or CONFIDENTIAL transport guarantee. Range of values: NONE—The application does not require any transport guarantees. INTEGRAL—The application requires that the data be sent between the client and server in such a way that it cannot be changed in transit. CONFIDENTIAL—The application requires that data be transmitted so as to prevent other entities from observing the contents of the transmission.

login-config

Use the optional login-config element to configure how the user is authenticated; the realm name that should be used for this application; and the attributes that are needed by the form login mechanism.

If this element is present, the user must be authenticated in order to access any resource that is constrained by a <security-constraint> defined in the Web Application. Once authenticated, the user can be authorized to access other resources with access privileges.

The following table describes the elements you can define within a login-config element.

Element | Required/ Optional | Description
--- | --- | ---
<auth-method> | Optional | Specifies the method used to authenticate the user. Possible values: BASIC - uses browser authentication FORM - uses a user-written HTML form CLIENT-CERT
<realm-name> | Optional | The name of the realm that is referenced to authenticate the user credentials. If omitted, the realm defined with the Auth Realm Name field on the Web Application—> Configuration—>Other tab of the Administration Console is used by default. For more information, see Managing WebLogic Security. Note: The <realm-name> element does not refer to security realms within WebLogic Server. This element defines the realm name to use in HTTP Basic authorization. Note: The system security realm is a collection of security information that is checked when certain operations are performed in the server. The servlet security realm is a different collection of security information that is checked when a page is accessed and basic authentication is used.
<form-login- config> | Optional | Use this element if you configure the <auth-method> to FORM. See form-login-config.

form-login-config

This is an element within the login-config.

Use the <form-login-config> element if you configure the <auth-method> to FORM.

.

Element | Required/ Optional | Description
--- | --- | ---
<form-login-page> | Required | The URI of a Web resource relative to the document root, used to authenticate the user. This can be an HTML page, JSP, or HTTP servlet, and must return an HTML page containing a FORM that conforms to a specific naming convention. For more information, see Setting Up Authentication for Web Applications.
<form-error-page> | Required | The URI of a Web resource relative to the document root, sent to the user in response to a failed authentication login.

security-role

The following table describes the elements you can define within a security-role element.

Element | Required/ Optional | Description
--- | --- | ---
<description> | Optional | A text description of this security role.
<role-name> | Required | The role name. The name you use here must have a corresponding entry in the WebLogic-specific deployment descriptor, weblogic.xml, which maps roles to principals in the security realm. For more information, see security-role-assignment.

env-entry

The optional env-entry element declares an environment entry for an application. Use a separate element for each environment entry.

The following table describes the elements you can define within an env-entry element.

Element | Required/ Optional | Description
--- | --- | ---
<description> | Optional | A textual description.
<env-entry-name> | Required | The name of the environment entry.
<env-entry-value> | Required | The value of the environment entry.
<env-entry-type> | Required | The type of the environment entry. Can be set to one of the following Java types: java.lang.Boolean java.lang.String java.lang.Integer java.lang.Double java.lang.Float

ejb-ref

The optional ejb-ref element defines a reference to an EJB resource. This reference is mapped to the actual location of the EJB at deployment time by defining the mapping in the WebLogic-specific deployment descriptor file, weblogic.xml. Use a separate <ejb-ref> element to define each reference EJB name.

The following table describes the elements you can define within an ejb-ref element.

Element | Required/ Optional | Description
--- | --- | ---
<description> | Optional | A text description of the reference.
<ejb-ref-name> | Required | The name of the EJB used in the Web Application. This name is mapped to the JNDI tree in the WebLogic-specific deployment descriptor weblogic.xml. For more information, see ejb-reference-description.
<ejb-ref-type> | Required | The expected Java class type of the referenced EJB.
<home> | Required | The fully qualified class name of the EJB home interface.
<remote> | Required | The fully qualified class name of the EJB remote interface.
<ejb-link> | Optional | The <ejb-name> of an EJB in an encompassing J2EE application package.
<run-as> | Optional | A security role whose security context is applied to the referenced EJB. Must be a security role defined with the <security-role> element.

ejb-local-ref

The ejb-local-ref element is used for the declaration of a reference to an enterprise bean's local home. The declaration consists of:

- an optional description

- the EJB reference name used in the code of the web application that's referencing the enterprise bean

- the expected type of the referenced enterprise bean

- the expected local home and local interfaces of the referenced enterprise bean

- optional ejb-link information, used to specify the referenced enterprise bean

The following table describes the elements you can define within an ejb-local-ref element.

Element | Required/ Optional | Description
--- | --- | ---
<description> | Optional | A text description of the reference.
<ejb-ref-name> | Required | Contains the name of an EJB reference. The EJB reference is an entry in the Web application's environment and is relative to the java:comp/env context. The name must be unique within the Web application. It is recommended that name is prefixed with ejb/. For example: <ejb-ref-name>ejb/Payroll</ejb-ref-name>
> <ejb-ref-type> | Required | The ejb-ref-type element contains the expected type of the referenced enterprise bean. The ejb-ref-type element must be one of the following:
>     <ejb-ref-type>Entity</ejb-ref-type>
>     <ejb-ref-type>Session</ejb-ref-type>
<local-home> | Required | Contains the fully-qualified name of the enterprise bean's local home interface.
<local> | Required | Contains the fully-qualified name of the enterprise bean's local interface.
<ejb-link> | Optional | The ejb-link element is used in the ejb-ref or ejb-local-ref elements to specify that an EJB reference is linked to an enterprise bean. The name in the ejb-link element is composed of a path name specifying the ejb-jar containing the referenced enterprise bean with the ejb-name of the target bean appended and separated from the path name by "#". The path name is relative to the war file containing the web application that is referencing the enterprise bean. This allows multiple enterprise beans with the same ejb-name to be uniquely identified. Used in: ejb-local-ref, ejb-ref Examples: <ejb-link>EmployeeRecord</ejb-link> <ejb-link>../products/product.jar#ProductEJB</ejb-link>