LiteSpeed Web Server Users' Manual

Version 5.0 Rev. 1
Context

Java Web App Context

Table of Contents

Java Web App Context

URI | Location | Servlet Engine | Enable Expires | Expires Default | Expires By Type | Extra Headers | Auto Index | Index Files | Allow Override | Realm | Authentication Name | Require (Authorized Users/Groups) | Access Allowed | Access Denied | Authorizer | Add Default Charset | Customized Default Charset | Enable Public Cache | Cache Expire Time (seconds) | Cache Stale Age (seconds) | Cache Request with Query String | Cache Request with Cookie | Cache Response with Cookie | Ignore Request Cache-Control | Ignore Response Cache-Control | Enable Private Cache | Private Cache Expire Time (seconds) | Enable IP Geolocation | 

Java Web App ContextGo to top
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 Application 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/.
URIGo to top
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
LocationGo to top
Description: Specifies the directory that contains the files for this web application. This is the directory containing "WEB-INF/web.xml".
Syntax: path
Servlet EngineGo to top
Description: Specifies the name of the servlet engine that serves this web application. Servlet engines must be defined in the External Application section at the server or virtual host level.
Syntax: Select from drop down list
Enable ExpiresGo to top
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 DefaultGo to top
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 TypeGo to top
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/*.
Extra HeadersGo to top
Description: Specifies extra response headers to be added. Multiple headers can be added, one header per line. Put "NONE" to disable headers inherited from parent content.
Syntax: "[HeaderName]: [HeaderValue]" in each line.
Example: Cache-control: no-cache, no-store
My-header: Custom header value
Auto IndexGo to top
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: [Security] It is recommended to turn off Auto Index wherever possible to prevent revealing confidential data.
See Also: Index Files, Auto Index URI
Index FilesGo to top
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 file names.
Tips: [Performance] Only set index files that you need.
Allow OverrideGo to top
Description: Specifies what directives in an access control file are allowed. An access control file can be placed in a directory to control the accessibility of files under that directory.
  • When nothing is checked, inherited default settings will be used.
  • When None is checked, access control files will be ignored.
  • When Limit is checked, directives "Order", "Allow from" and "Deny from" are allowed.
  • When Auth is checked, directives "AuthGroupFile", "AuthName", "AuthType", "AuthUserFile", and "Require" are allowed.
  • When FileInfo is checked, directives "Satisfy", "AddDefaultCharset", "AddType", "DefaultType", "ForceType", "ExpiresActive", "ExpiresDefault", "ExpiresByType", "Redirect", "RedirectTemp", "RedirectPermanent", "RewriteEngine", "RewriteOptions", "RewriteBase", "RewriteCond" and "RewriteRule" are allowed
  • When Indexes is checked, directive "DirectoryIndex" is allowed
  • When Options is checked, directive "Options" is allowed

Allow Override configuration is available at three levels: server, virtual host and context. If a configuration is not checked at the server level, the controlled directives will be disabled for the whole server whether or not it is enabled at lower levels. If something is enabled at the server level, virtual hosts will inherit same settings by default. Similarly context level settings will be inherited from virtual host settings. Lower levels can disable a setting that is enabled at an upper level, but cannot enable a setting that is disabled at an upper level.
Syntax: Select from checkbox
Tips: [Performance] If there is no need for directory level configuration customization, check None.
RealmGo to top
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 NameGo to top
Description: Specifies an alternative name for the authorization realm for current context. If it is 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)Go to top
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.
If this setting is not specified, all valid users will be able to access this resource.
Access AllowedGo to top
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: Sub-networks can be written as 192.168.1.0/255.255.255.0, 192.168.1 or 192.168.1.*.
Access DeniedGo to top
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: Sub-networks can be written as 192.168.1.0/255.255.255.0, 192.168.1 or 192.168.1.*.
AuthorizerGo to top
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 CharsetGo to top
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 CharsetGo to top
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, like utf-8
Example: utf-8
Enable Public CacheGo to top
Description: Specifies whether to turn on public cache for the current context, either at the server level, virtual host level, or context level.

Virtual hosts configured through Apache httpd.conf can use the "CacheEnable" and "CacheDisable" directives at the server, virtual host, context, file, and location level or in .htaccess. "CacheEnable" and "CacheDisable" directives are compatible with Apache mod_cache directives. However, when used at the context, file, or location level or in a .htaccess, "CacheEnable" and "CacheDisable" will only be applied to all directories below the current level. URL parameters will be ignored.
Syntax: Select from radio box
Tips: [Performance] It is not recommended to store large objects with low hit rates in the cache. This may result in high I/O wait and reduce overall server performance.
Cache Expire Time (seconds)Go to top
Description: Specifies how long an object will be cached. The default is "86400" seconds (one day).
Syntax: Integer number
Cache Stale Age (seconds)Go to top
Description: Specifies how long an object will continue to be served after its cache has expired but bbefore the new cache is available. The default is "10" seconds.
Syntax: Integer number
Cache Request with Query StringGo to top
Description: Specifies whether to cache a request with a query string in the URL. The default is "Yes". When a URL rewrite is involved, the server will check against the rewritten URL.
Syntax: Select from radio box
Cache Request with CookieGo to top
Description: Specifies whether to cache a request containing cookies. The default is "Yes".
Syntax: Select from radio box
Cache Response with CookieGo to top
Description: Specifies whether to cache a response containing cookies. The default is "Yes".
Syntax: Select from radio box
Ignore Request Cache-ControlGo to top
Description: Specifies whether to ignore Cache-Control request headers. The default is "No". If set to "Yes", the server may serve a cached object when "no-cache" has been set in Cache-Control.
Syntax: Select from radio box
Ignore Response Cache-ControlGo to top
Description: Specifies whether to ignore Cache-Control response headers. The default is "No". If set to "Yes", the response can be cached by the server even when "no-store", "private" has been set in a Cache-Control header.
Syntax: Select from radio box
Enable Private CacheGo to top
Description: Specifies whether to turn on private cache for the current context, either at server level, virtual host level, or directory level.

Private cache will cache a copy per user based on IP and cookies.
Virtual hosts configured through Apache httpd.conf can use the "CacheEnable private /url" and "CacheDisable private /url" directives at server, virtual host, directory, files, and location levels or in a .htaccess file. "CacheEnable private" and "CacheDisable private" are compatible with Apache's mod_cache directives and will be applied to all directories below the current level. However, when used at the directory, file, and location level or in a .htaccess file, "CacheEnable private" and "CacheDisable private" will be applied to all directories below the current level. URL parameters will be ignored.
Syntax: Select from radio box
Tips: [Performance] It is not recommended to store large objects with low hit rates in the cache. This may result in high I/O wait and reduce overall server performance.
Private Cache Expire Time (seconds)Go to top
Description: Specifies how long an object will be cached in private cache. The default is "60" seconds.
Syntax: Integer number
Enable IP GeolocationGo to top
Description: Enterprise Edition Only Specifies whether to enable/disable IP Geolocation lookup. It 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
See Also: Use Client IP in Header, DB File Path, DB Cache Type