JSP engine configuration parameters

Specifies whether the JSP container can store multiple values for a custom tag attribute. Set this parameter to true to allow the JSP container to store multiple values. The default value for this parameter is false. This parameter requires regeneration of Java source.

Specifies whether the generated Java classes should contain support for the Developer Kit, Java Technology Edition 1.4 Assertion facility. The effect of setting this parameter to true is that the -source 1.4 option is passed to the Java compiler. The default for this parameter is false. This parameter requires regeneration of Java source.

Specifies whether the compiler includes debugging information in the generated class file. When you set this parameter to true, the -g option is passed to the Java compiler. The default for this parameter is false. This parameter requires regeneration of Java source.

Specifies whether to convert start and end attributes of the repeat tag to strings before they are used. The default for this parameter is false. This parameter requires regeneration of Java source.

Specifies whether the compiler generates deprecation warnings when compiling the generated Java source. When you set this parameter to true, the -deprecation option is passed to the Java compiler. The default for this parameter is false. This parameter requires regeneration of Java source.

Set this parameter to true to disable the commons-el expression cache if you are experiencing out of memory conditions because the hash maps are held by the expression evaluator. The default for this parameter is false.

If this option is set to true, the JSP engine at runtime does not translate and compile JSP files; the JSP engine loads only precompiled class files. JSP source files do not need to be present in order to load class files. When this option is set to true, you can install an application without JSP source, but the application must have precompiled class files. There is a web container custom property with the same name that is used to determine the behavior of all web modules installed in a server. If both the web container custom property and the JSP engine option are set, the JSP engine option takes precedence. The default for this parameter is false.

Set this option is set to true to prevent the JSP engine from searching the application installation directories for the taglib descriptor (TLD) files when an application starts. If this option is set to false, when an application starts, the JSP engine searches the application installation directories for the TLD files. The default for this parameter is false.

There is a web container custom property, com.ibm.wsspi.jsp.disableTldSearch, that can be used to specify whether, when an application starts, the JSP engines in all web modules installed in a server do not search the application installation directories for the TLD files. If conflicting values are set for the web container custom property and the JSP engine option, the setting for the JSP engine option takes precedence.

Set this option to true to handle escape characters and quotations properly when determining whether to evaluate an expression.

<input type="text" value="${fn:substring('1234567', 0,4)}"/>

<jspAttributes xmi:id="JSPAttribute_1" 
name="evalQuotedAndEscapedExpression" value="true"/> 

<?xml version="1.0" encoding="UTF-8"?>
<web-ext
   xmlns="http://websphere.ibm.com/xml/ns/javaee"
   xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://websphere.ibm.com/xml/ns/javaee http://websphere.ibm.com/xml/ns/javaee/ibm-web-ext_1_0.xsd"
      version="1.0">
   <file-serving-attribute name="extendedDocumentRoot" value="/opt/extDocRootDir" />
   <jsp-attribute name="evalQuotedAndEscapedExpression" value="true" />
   <jsp-attribute name="extendedDocumentRoot" value="/opt/extDocRootDir","${MY_CUSTOM_VARIABLE}"  />
   
   <reload-interval value="3"/>
   <auto-encode-requests value="false"/>
   <auto-encode-responses value="false"/>
   <enable-directory-browsing value="false"/>
   <enable-file-serving value="true"/>
   <pre-compile-jsps value="false"/>
   <enable-reloading value="true"/>
   <enable-serving-servlets-by-class-name value="false" />	
</web-ext>

To apply this behavior globally across all web applications, you can set the com.ibm.wsspi.jsp.evalQuotedAndEscapedExpression web container custom property to true.

Use the extended document root facility when applications require access to files outside of the application web application archive (WAR) directory. This facility enables you to configure an application with one or more directory paths from which you can serve static files and JSP files. You can use this attribute when an application requires access to files that exist outside of the web application archive (WAR) directory. For example, if several applications require access to a set of common files, you can place the common files in a directory to which you can link each application as an extended document root directory.

To configure an application with an extended document root, add an extendedDocumentRoot attribute as a file-serving attribute to the ibm-web-ext.xmi or ibm-web-ext.xml file for the application. The value of this attribute is a comma-delimited list of directories that serve as the root directory location for the static files.

<fileServingAttributes xmi:id="FileServingAttribute_1" name="extendedDocumentRoot" value="/opt/extDocRootDir"/>

<?xml version="1.0" encoding="UTF-8"?>
<web-ext
   xmlns="http://websphere.ibm.com/xml/ns/javaee"
   xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://websphere.ibm.com/xml/ns/javaee http://websphere.ibm.com/xml/ns/javaee/ibm-web-ext_1_0.xsd"
      version="1.0">
   <file-serving-attribute name="extendedDocumentRoot" value="/opt/extDocRootDir" />
   <jsp-attribute name="evalQuotedAndEscapedExpression" value="true" />
   <jsp-attribute name="extendedDocumentRoot" value="/opt/extDocRootDir", "${MY_CUSTOM_VARIABLE}"/>
   <reload-interval value="3"/>
   <auto-encode-requests value="false"/>
   <auto-encode-responses value="false"/>
   <enable-directory-browsing value="false"/>
   <enable-file-serving value="true"/>
   <pre-compile-jsps value="false"/>
   <enable-reloading value="true"/>
   <enable-serving-servlets-by-class-name value="false" />	
</web-ext>

To configure an application with an extended document root from which JSP files are served, add an extendedDocumentRoot attribute as a JSP attribute to the ibm-web-ext.xmi or ibm-web-ext.xml file. The value of this attribute is a comma-delimited list of directories that serve as the root directory location for the JSP files.

<jspAttributes xmi:id="JSPAttribute_1" name="extendedDocumentRoot" value="/opt/extDocRootDir"/>

<?xml version="1.0" encoding="UTF-8"?>
<web-ext
   xmlns="http://websphere.ibm.com/xml/ns/javaee"
   xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://websphere.ibm.com/xml/ns/javaee http://websphere.ibm.com/xml/ns/javaee/ibm-web-ext_1_0.xsd"
      version="1.0">
   <file-serving-attribute name="extendedDocumentRoot" value="/opt/extDocRootDir" />
   <jsp-attribute name="evalQuotedAndEscapedExpression" value="true" />
   <jsp-attribute name="extendedDocumentRoot" value="/opt/extDocRootDir", "${MY_CUSTOM_VARIABLE}" />
   <reload-interval value="3"/>
   <auto-encode-requests value="false"/>
   <auto-encode-responses value="false"/>
   <enable-directory-browsing value="false"/>
   <enable-file-serving value="true"/>
   <pre-compile-jsps value="false"/>
   <enable-reloading value="true"/>
   <enable-serving-servlets-by-class-name value="false" />	
</web-ext>

You can also use an extendedDocumentRoot attribute to define a WebSphere variable on multiple nodes to the appropriate directory.

<jspAttributes xmi:id="JSPAttribute_2" name="extendedDocumentRoot" 
  		value="${MY_CUSTOM_VARIABLE}"/>

<jsp-attribute name="extendedDocumentRoot" 
    value="${MY_CUSTOM_VARIABLE}" />

<?xml version="1.0" encoding="UTF-8"?>
<com.ibm.ejs.models.base.extensions.webappext:WebAppExtension xmi:version="2.0"
xmlns:xmi="https://www.omg.org/XMI"
xmlns:com.ibm.ejs.models.base.extensions.webappext="webappext.xmi" xmi:id="WebAppExtension_1"
          reloadInterval="3"
          reloadingEnabled="true"
          fileServingEnabled="true">
      <webApp href="WEB-INF/web.xml#WebApp_ID/">
      <fileServingAttributes xmi:id="FileServingAttribute_1" name="extendedDocumentRoot"
       value="/opt/extDocRootDir/">
      <jspAttributes xmi:id="JSPAttribute_1" name="extendedDocumentRoot"
       value="/opt/extDocRootDir/">
<com.ibm.ejs.models.base.extensions.webappext:WebAppExtension>

<?xml version="1.0" encoding="UTF-8"?>
<web-ext
   xmlns="http://websphere.ibm.com/xml/ns/javaee"
   xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://websphere.ibm.com/xml/ns/javaee http://websphere.ibm.com/xml/ns/javaee/ibm-web-ext_1_0.xsd"
      version="1.0">
   <file-serving-attribute name="extendedDocumentRoot" value="/opt/extDocRootDir" />
   <jsp-attribute name="evalQuotedAndEscapedExpression" value="true" />
   <jsp-attribute name="extendedDocumentRoot" value="/opt/extDocRootDir","${MY_CUSTOM_VARIABLE}"  />
   
   <reload-interval value="3"/>
   <auto-encode-requests value="false"/>
   <auto-encode-responses value="false"/>
   <enable-directory-browsing value="false"/>
   <enable-file-serving value="true"/>
   <pre-compile-jsps value="false"/>
   <enable-reloading value="true"/>
   <enable-serving-servlets-by-class-name value="false" />	
</web-ext>

If the request is a valid partial request for a welcome file, a 404 error is returned. If the JSP file is located inside a JAR file and the reloadEnabled attribute value is true, the time stamp of the JAR file is used for isOutDated checks for recompile purposes. The default for this parameter is null.

Specifies the encoding that is used when the .java file is generated, and when it is compiled by the Java compiler. Set this parameter when the page encoding of your JSP pages is not UTF-8 compatible. When javaEncoding is set, the encoding is passed to the Java compiler through the -encoding argument. Note that encoding is not supported by Jikes. The default is UTF-8. This parameter requires regeneration of Java source.

This JSP engine parameter was introduced in WebSphere Application Server version 6.1. Use this parameter instead of the compileWithAssert parameter, although compile WithAssert still works in version 6.1.

The WebSphere Application Server creates a JSPExtensionClassLoader object for each JSP in an application. This can result in these objects taking up a lot of native memory, which can lead to an OutOfMemoryException. This integer value determines how many JSPExtensionClassLoader objects to keep loaded in memory.

<jspAttributes xmi:id="JSPAttribute_1" name="jspClassLoaderLimit" value="1500"/>

While jspClassLoaderLimit specifies the number of JSPExtensionClassLoader objects to keep loaded in memory, this comma-delimited list of JSP values indicate what JSPs are NOT to be unloaded regardless of the limit set by jspClassLoaderLimit.

<jspAttributes xmi:id="JSPAttribute_2" name="jspClassLoaderExclusionList" value="/test/RappHTML2.jsp,/test/RappHTML4.jsp"/>

For JSP files with extensions other than the four standard extensions, *.jsp, *.jspx, *.jsw, and *.jsv, you can configure this the extensions using this parameter. These extensions are added to the standard extensions.

The preferred method for doing this is to create a <jsp-property-group> in web.xml, and add a <url-pattern> tag for each extension.

The JSP engine can handle a list of file extensions that is separated by a colon or semicolon. For example, *.ext1;*.ext2:*.extn

Indicates that the Java files generated by the JSP compiler during the translation phase of the processing are retained. The default for this parameter is false. This parameter requires regeneration of Java source.

Indicates that the class files generated by the JSP compiler during the translation phase of the processing are retained. The default for this parameter is true. This parameter requires regeneration of Java source.

During the translation phase of a tag file that is compiled, the JSP container implicitly uses the pageContext variable for the PageContext object. The use of the pageContext variable as an implicit variable name in tag files does not comply with the JSP Specification. If compilation errors occur for applications that use a local pageContext variable in their tag file, set the modifyPageContextVariable attribute totrue to remove the use of the pageContext variable name in the generated Java code for tag files.

Determines whether a JSP file is retranslated and recompiled after application startup for the first time the file is requested. If recompileJspOnRestart is false, a JSP file is still compiled, if necessary, on the first request to that JSP file unless the parameter disableJspRuntimeCompilation is true. The default for this parameter is false.

Determines whether or not a JSP file is translated and compiled at runtime if the JSP file or its dependencies (see trackDependencies) are modified.

If reloadEnabled is false, a JSP file is still compiled, if necessary, on the first request to it unless the parameter disableJspRuntimeCompilation is true. The default for this parameter is false.

If this JSP engine parameter is not specified, the equivalent web container parameter for web module class reloading is used. However, for an application whose deployment descriptor is at the Servlet 2.2 level, the default is true. This is done for the support of applications being migrated from WebSphere Application Server Version 4.x.

If reloading is enabled, reloadInterval determines the delay between checks to see if a JSP file is outdated.

For example, if reloadInterval is 5, the JSP engine checks to see if a JSP file is outdated only when the last such check was done more than 5 seconds prior to the current request for the JSP file. The larger the reloadInterval, the less frequently the JSP engine checks for the need to reload a JSP file. If this JSP engine parameter is not specified, the equivalent web container parameter for web module class reloading is used. However, for an application whose deployment descriptor is at the Servlet 2.2 level, the default is 5 seconds. This is done for the support of applications being migrated from WebSphere Application Server Version 4.x.

Specifies the directory where the generated class files are created.

The system property com.ibm.websphere.servlet.temp.dir is used to set the scratchdir option on a server-wide basis. The JSP engine scratchdir parameter takes precedence over the system property com.ibm.websphere.servlet.temp.dir. The default for this parameter is profile_root/temp. This parameter requires regeneration of Java source.

If reloading is enabled, trackDependencies determines whether the JSP engine tracks modifications to the requested JavaServer Pages files dependencies as well as to the JSP file itself.

If useFullPackageNames is true, the JSP engine generates and loads JSP classes using full package names.

The default is to generate all JSP classes in the same package. (For more information, refer to the Packages and directories for generated .java and .class files topic). The JSP engine's class loader knows how to load JSP classes when they are all in the same package.

The default method of generating all JSP classes in the same package has the benefit of generating smaller file-system paths. Full package names has the benefit of enabling the configuration of precompiled JSP class files as servlets in the web.xml file without the use of the jsp-file attribute, resulting in a single class loader, the web application's class loader, that is used to load all such JSP classes. Similarly, when the JSP engine's configuration attributes useFullPackageNames and disableJspRuntimeCompilation are both true, a single class loader is used to load all JSP classes, even if the JSP files are not configured as servlets in the web.xml file.

When useFullPackageNames is set to true, the batch compiler generates a generated_web.xml file in the web module's WEB-INF directory. This file contains servlet configuration information for each JSP file that was successfully translated and compiled. The information can optionally be copied into the web module web.xml file so that the JSP files are loaded as servlets by the web container. Note that if a JSP file is configured as a servlet in this way, no reloading of the JSP file is done at runtime if the JSP file is modified. This is because the JSP file is treated as a regular servlet and requests for it do not pass through the JSP engine. This parameter requires regeneration of Java source.

The JSP engine implicitly recognizes tsx and jsx as tag library prefixes for tag libraries supplied by the JSP engine. If tsx or jsx are used as prefixes for a customer's tag library, the customer's tag library overrides the implicit tag library. However, the implicit tag library is still cached by the JSP engine. Explicitly setting this parameter to false tells the engine not to cache the implicit tag library, and save resources. The default for this parameter is true.

The default URL for the tsx tags is http://websphere.ibm.com/tags/tsx. The default URI for the jsx tags is http://websphere.ibm.com/tags/jsx.

You might need to define the tsx or jsx tag library prefix with a different URI than its default URI. Also, you might need to define the same library prefix with a different URI. In these two situations, you can set the com.ibm.wsspi.jsp.allowtaglibprefixredefinition custom property to avoid translation errors. For more information, see the documentation about JavaServer Pages custom properties.

Specifies that the JSP engine translate and compile Java code in the system memory.

Specifies whether Jikes is used for compiling Java sources.

Jikes is not shipped with WebSphere Application Server. The default for this parameter is false. This parameter requires regeneration of Java source.

Enables or disables the reuse of custom tag handlers on an individual JavaServer Pages basis. The default for this parameter is false. This parameter requires regeneration of Java source.

When thread-level tag handler pooling is used, tag handlers may be reused among separate occurrences of a custom action across all JSP pages in a single web module across separate requests. The default for this parameter is false. This parameter requires regeneration of Java source.

Indicates that the compiler generates verbose output when compiling the generated Java source code. The effect of setting this parameter to true is that the -verbose option is passed to the Java compiler. The default for this parameter is false. This parameter requires regeneration of Java source.