Java Web App Context
Table of Contents
URI | Location | Servlet Engine | Enable Expires | Expires Default | Expires By Type | Header Operations | Auto Index | Index Files | Realm | Authentication Name | Require (Authorized Users/Groups) | Access Allowed | Access Denied | Authorizer | Add Default Charset | Customized Default Charset | Enable GeoLocation Lookup
Java Web App Context⇑
Description
Many people running Java applications use the servlet engine to serve static content as well. But no servlet engine is nearly as efficient as LiteSpeed Web Server for these processes. In order to improve the overall performance, LiteSpeed Web Server can be configured as a gateway server, which serves static content and forwards dynamic Java page requests to the servlet engine.
LiteSpeed Web Server requires certain contexts to be defined in order to run a Java application. A Java Web App Context automatically creates all required contexts based on the Java web application's configuration file (WEB-INF/web.xml).
There are a few points you need to keep in mind when setting up a Java Web App Context:
- A Servlet Engine external application must be set up in External Apps before Java Web App Context can be set up.
- A Script Handler for .jsp files should be defined as well.
- If the web application is packed into a .war file, the .war file must be expanded. The server cannot access compressed archive files.
- For the same resources, the same URL should be used no matter whether it is accessed through LiteSpeed Web Server or through the servlet engine's built-in HTTP server.
For example, Tomcat 4.1 is installed under /opt/tomcat. Files for the "examples" web application are located at /opt/tomcat/webapps/examples/. Through Tomcat's built-in HTTP server, the "examples" web application is thus accessed with a URI like "/examples/***". The corresponding Java Web App Context should thus be configured: URI = /examples/, Location = /opt/tomcat/webapps/examples/.
URI⇑
Description
Specifies the URI for this context. The URI should start with a "/". If a URI ends with a "/", then this context will include all sub-URIs under this URI.
Syntax
URI
Location⇑
Description
Specifies the directory that contains the files for this web application. This is the directory containing "WEB-INF/web.xml".
Default value: $DOC_ROOT + URI
Syntax
path
Servlet Engine⇑
Description
Specifies the name of the servlet engine that serves this web application. Servlet engines must be defined in the External Apps section at the server or virtual host level.
Syntax
Select from drop down list
Enable Expires⇑
Description
Specifies whether to generate an Expires header for static files. If enabled, an Expires header will be generated based on Expires Default and Expires By Type.
This can be set at server, virtual host and context level. Lower level settings will override higher level ones, i.e. context settings will override virtual host settings and virtual host settings will override server settings.
Syntax
Select from radio box
Expires Default⇑
Description
Specifies default settings for Expires header generation. This setting takes effect when Enable Expires is set to "Yes". It can be overridden by Expires By Type. Do not set this default at the server or virtual host level unless you have to, since it will generate Expires headers for all pages. Most of time this should be set at the context level for certain directories that do not change often. If there is no default setting, no Expires header will be generated for types not specified in Expires By Type.
Syntax
A|Mseconds
The file will expire after base time(A|M) plus specified seconds. Base time "A" sets the value to the client's access time and "M" to the file's last modified time.
Expires By Type⇑
Description
Specifies Expires header settings for individual MIME types.
Syntax
Comma delimited list of "MIME-type=A|Mseconds". The file will expire after base time (A|M) plus specified seconds.
Base time "A" sets the value to the client's access time and "M" to the file's last modified time. MIME-type accepts wildcard "*", like image/*.
Header Operations⇑
Description
Specifies additional response/request headers to be added. Multiple header directives can be added with one directive per line. "NONE" can be used to disable parent header inheritance. If no directive is provided 'Header' is assumed.
Syntax
[Header]|RequestHeader [condition] set|append|merge|add|unset header [value] [early|env=[!]variable]
Example
append Cache-control no-store
Header set My-header cust_header_val
RequestHeader set My-req-header cust_req_header_val
Tips
Syntax and usage are similar to Apache's mod_headers directives for supported operations.
The 'Header' directive is is optional and can be excluded or left in when copying rules from elsewhere without issue.
Auto Index⇑
Description
Specifies whether to generate a directory index on the fly when index files listed in Index Files are not available in a directory. This option is customizable at the virtual host and context level, and is inherited along the directory tree until it is explicitly overridden. You can customize the generated index page. Please check online wiki How-tos.
Syntax
Select from radio box
Tips
It is recommended to turn off Auto Index wherever possible to prevent revealing confidential data.
See Also
Index Files⇑
Description
Specifies names of index files that will be searched sequentially when a URL is mapped to a directory. You can customize it at the server, virtual host, and context level.
Syntax
Comma-delimited list of index filenames.
Tips
Only set index files that you need.
Realm⇑
Description
Specifies the authorization realm for this context. When specified, a valid username and password must be provided in order to access this context. Authorization Realms are set up in the Virtual Host Security section. This setting uses each realm's Realm Name.
Syntax
Select from drop down list
Authentication Name⇑
Description
Specifies an alternative name for the authorization realm for the current context. If not specified, the original realm name will be used. The authentication name is displayed on the browser's login pop-up.
Require (Authorized Users/Groups)⇑
Description
Specifies which user/group can access this context. This allows you to use one user/group database (specified in Realm) across a number of contexts, but only allow certain users/groups from that database to access this context.
Syntax
Syntax is compatible with Apache's Require directive. For example:
- user username [username ...]
Only listed users can access this context. - group groupid [groupid ...]
Only users belonging to the listed groups can access this context.
Access Allowed⇑
Description
Specifies which IPs or sub-networks are allowed to access resources under this context. Together with Access Denied and server/virtual host level access control, accessibility is determined by the smallest scope that a client's IP address falls into.
Syntax
Comma-delimited list of IPs/sub-networks.
Example
Access Denied⇑
Description
Specifies which IPs or sub-networks are NOT allowed to access resources under this context. Together with Access Allowed and server/virtual host-level access control, accessibility is determined by the smallest scope that a client's IP address falls into.
Syntax
Comma-delimited list of IPs/sub-networks.
Example
Authorizer⇑
Description
Specifies an external application that can be used to generate authorized/unauthorized decisions. Currently, only the FastCGI Authorizer is available. For more details about the FastCGI Authorizer role, please visit http://www.fastcgi.com.
Syntax
Select from drop down list
Add Default Charset⇑
Description
Specifies whether to add a character set tag to the "Content-Type" response header, when content type is either "text/html" or "text/plain" without any parameters. When set to Off, this function is disabled. When set to On, either the character set specified by Customized Default Charset or the default "iso-8859-1" will be added.
Syntax
Select from radio box
Customized Default Charset⇑
Description
Specifies a character set to be used when Add Default Charset is On. This is optional. The default value is iso-8859-1. This entry has no effect when Add Default Charset is Off.
Syntax
Name of a character set.
Example
Enable GeoLocation Lookup⇑
Description
Specifies whether to enable/disable IP Geolocation lookup. Can be set at server, virtual host, or context level. IP Geolocation is disabled by default when using value "Not Set".
Syntax
Select from radio box