소스 파일 최초 업로드
This commit is contained in:
ByeonJungHun
403
tomcat/webapps.dist/docs/jasper-howto.html
Normal file
403
tomcat/webapps.dist/docs/jasper-howto.html
Normal file
@@ -0,0 +1,403 @@
|
||||
<!DOCTYPE html SYSTEM "about:legacy-compat">
|
||||
<html lang="en"><head><META http-equiv="Content-Type" content="text/html; charset=UTF-8"><link href="./images/docs-stylesheet.css" rel="stylesheet" type="text/css"><title>Apache Tomcat 9 (9.0.74) - Jasper 2 JSP Engine How To</title><meta name="author" content="Glenn L. Nielsen"><meta name="author" content="Peter Rossbach"></head><body><div id="wrapper"><header><div id="header"><div><div><div class="logo noPrint"><a href="https://tomcat.apache.org/"><img alt="Tomcat Home" src="./images/tomcat.png"></a></div><div style="height: 1px;"></div><div class="asfLogo noPrint"><a href="https://www.apache.org/" target="_blank"><img src="./images/asf-logo.svg" alt="The Apache Software Foundation" style="width: 266px; height: 83px;"></a></div><h1>Apache Tomcat 9</h1><div class="versionInfo">
|
||||
Version 9.0.74,
|
||||
<time datetime="2023-04-13">Apr 13 2023</time></div><div style="height: 1px;"></div><div style="clear: left;"></div></div></div></div></header><div id="middle"><div><div id="mainLeft" class="noprint"><div><nav><div><h2>Links</h2><ul><li><a href="index.html">Docs Home</a></li><li><a href="https://cwiki.apache.org/confluence/display/TOMCAT/FAQ">FAQ</a></li><li><a href="#comments_section">User Comments</a></li></ul></div><div><h2>User Guide</h2><ul><li><a href="introduction.html">1) Introduction</a></li><li><a href="setup.html">2) Setup</a></li><li><a href="appdev/index.html">3) First webapp</a></li><li><a href="deployer-howto.html">4) Deployer</a></li><li><a href="manager-howto.html">5) Manager</a></li><li><a href="host-manager-howto.html">6) Host Manager</a></li><li><a href="realm-howto.html">7) Realms and AAA</a></li><li><a href="security-manager-howto.html">8) Security Manager</a></li><li><a href="jndi-resources-howto.html">9) JNDI Resources</a></li><li><a href="jndi-datasource-examples-howto.html">10) JDBC DataSources</a></li><li><a href="class-loader-howto.html">11) Classloading</a></li><li><a href="jasper-howto.html">12) JSPs</a></li><li><a href="ssl-howto.html">13) SSL/TLS</a></li><li><a href="ssi-howto.html">14) SSI</a></li><li><a href="cgi-howto.html">15) CGI</a></li><li><a href="proxy-howto.html">16) Proxy Support</a></li><li><a href="mbeans-descriptors-howto.html">17) MBeans Descriptors</a></li><li><a href="default-servlet.html">18) Default Servlet</a></li><li><a href="cluster-howto.html">19) Clustering</a></li><li><a href="balancer-howto.html">20) Load Balancer</a></li><li><a href="connectors.html">21) Connectors</a></li><li><a href="monitoring.html">22) Monitoring and Management</a></li><li><a href="logging.html">23) Logging</a></li><li><a href="apr.html">24) APR/Native</a></li><li><a href="virtual-hosting-howto.html">25) Virtual Hosting</a></li><li><a href="aio.html">26) Advanced IO</a></li><li><a href="maven-jars.html">27) Mavenized</a></li><li><a href="security-howto.html">28) Security Considerations</a></li><li><a href="windows-service-howto.html">29) Windows Service</a></li><li><a href="windows-auth-howto.html">30) Windows Authentication</a></li><li><a href="jdbc-pool.html">31) Tomcat's JDBC Pool</a></li><li><a href="web-socket-howto.html">32) WebSocket</a></li><li><a href="rewrite.html">33) Rewrite</a></li><li><a href="cdi.html">34) CDI 2 and JAX-RS</a></li><li><a href="graal.html">35) AOT/GraalVM Support</a></li></ul></div><div><h2>Reference</h2><ul><li><a href="RELEASE-NOTES.txt">Release Notes</a></li><li><a href="config/index.html">Configuration</a></li><li><a href="api/index.html">Tomcat Javadocs</a></li><li><a href="servletapi/index.html">Servlet 4.0 Javadocs</a></li><li><a href="jspapi/index.html">JSP 2.3 Javadocs</a></li><li><a href="elapi/index.html">EL 3.0 Javadocs</a></li><li><a href="websocketapi/index.html">WebSocket 1.1 Javadocs</a></li><li><a href="jaspicapi/index.html">JASPIC 1.1 Javadocs</a></li><li><a href="annotationapi/index.html">Common Annotations 1.3 Javadocs</a></li><li><a href="https://tomcat.apache.org/connectors-doc/">JK 1.2 Documentation</a></li></ul></div><div><h2>Apache Tomcat Development</h2><ul><li><a href="building.html">Building</a></li><li><a href="changelog.html">Changelog</a></li><li><a href="https://cwiki.apache.org/confluence/display/TOMCAT/Tomcat+Versions">Status</a></li><li><a href="developers.html">Developers</a></li><li><a href="architecture/index.html">Architecture</a></li><li><a href="tribes/introduction.html">Tribes</a></li></ul></div></nav></div></div><div id="mainRight"><div id="content"><h2>Jasper 2 JSP Engine How To</h2><h3 id="Table_of_Contents">Table of Contents</h3><div class="text">
|
||||
<ul><li><a href="#Introduction">Introduction</a></li><li><a href="#Configuration">Configuration</a></li><li><a href="#Known_issues">Known issues</a></li><li><a href="#Production_Configuration">Production Configuration</a></li><li><a href="#Web_Application_Compilation">Web Application Compilation</a></li><li><a href="#Optimisation">Optimisation</a></li></ul>
|
||||
</div><h3 id="Introduction">Introduction</h3><div class="text">
|
||||
|
||||
<p>Tomcat 9.0 uses the Jasper 2 JSP Engine to implement
|
||||
the <a href="https://cwiki.apache.org/confluence/display/TOMCAT/Specifications">JavaServer Pages 2.3</a>
|
||||
specification.</p>
|
||||
|
||||
<p>Jasper 2 has been redesigned to significantly improve performance over
|
||||
the original Jasper. In addition to general code improvements the following
|
||||
changes were made:</p>
|
||||
<ul>
|
||||
<li><strong>JSP Custom Tag Pooling</strong> - The java objects instantiated
|
||||
for JSP Custom Tags can now be pooled and reused. This significantly boosts
|
||||
the performance of JSP pages which use custom tags.</li>
|
||||
<li><strong>Background JSP compilation</strong> - If you make a change to
|
||||
a JSP page which had already been compiled Jasper 2 can recompile that
|
||||
page in the background. The previously compiled JSP page will still be
|
||||
available to serve requests. Once the new page has been compiled
|
||||
successfully it will replace the old page. This helps improve availability
|
||||
of your JSP pages on a production server.</li>
|
||||
<li><strong>Recompile JSP when included page changes</strong> - Jasper 2
|
||||
can now detect when a page included at compile time from a JSP has changed
|
||||
and then recompile the parent JSP.</li>
|
||||
<li><strong>JDT used to compile JSP pages</strong> - The
|
||||
Eclipse JDT Java compiler is now used to perform JSP java source code
|
||||
compilation. This compiler loads source dependencies from the container
|
||||
classloader. Ant and javac can still be used.</li>
|
||||
</ul>
|
||||
|
||||
|
||||
<p>Jasper is implemented using the servlet class
|
||||
<code>org.apache.jasper.servlet.JspServlet</code>.</p>
|
||||
|
||||
</div><h3 id="Configuration">Configuration</h3><div class="text">
|
||||
|
||||
<p>By default Jasper is configured for use when doing web application
|
||||
development. See the section <a href="#Production_Configuration">
|
||||
Production Configuration</a> for information on configuring Jasper
|
||||
for use on a production Tomcat server.</p>
|
||||
|
||||
<p>The servlet which implements Jasper is configured using init parameters
|
||||
in your global <code>$CATALINA_BASE/conf/web.xml</code>.
|
||||
</p>
|
||||
<ul>
|
||||
<li><strong>checkInterval</strong> - If development is false and checkInterval
|
||||
is greater than zero, background compiles are enabled. checkInterval is the time
|
||||
in seconds between checks to see if a JSP page (and its dependent files) needs
|
||||
to be recompiled. Default <code>0</code> seconds.</li>
|
||||
|
||||
<li><strong>classdebuginfo</strong> - Should the class file be compiled with
|
||||
debugging information? <code>true</code> or <code>false</code>, default
|
||||
<code>true</code>.
|
||||
</li>
|
||||
|
||||
<li><strong>classpath</strong> - Defines the class path to be used to compile
|
||||
the generated servlets. This parameter only has an effect if the ServletContext
|
||||
attribute org.apache.jasper.Constants.SERVLET_CLASSPATH is not set. This
|
||||
attribute is always set when Jasper is used within Tomcat. By default the
|
||||
classpath is created dynamically based on the current web application.</li>
|
||||
|
||||
<li><strong>compiler</strong> - Which compiler Ant should use to compile JSP
|
||||
pages. The valid values for this are the same as for the compiler attribute of
|
||||
Ant's
|
||||
<a href="https://ant.apache.org/manual/Tasks/javac.html#compilervalues">javac</a>
|
||||
task. If the value is not set, then the default Eclipse JDT Java compiler will
|
||||
be used instead of using Ant. There is no default value. If this attribute is
|
||||
set then <code>setenv.[sh|bat]</code> should be used to add
|
||||
<code>ant.jar</code>, <code>ant-launcher.jar</code> and <code>tools.jar</code>
|
||||
to the <code>CLASSPATH</code> environment variable.</li>
|
||||
|
||||
<li><strong>compilerSourceVM</strong> - What JDK version are the source files
|
||||
compatible with? (Default value: <code>1.8</code>)</li>
|
||||
|
||||
<li><strong>compilerTargetVM</strong> - What JDK version are the generated files
|
||||
compatible with? (Default value: <code>1.8</code>)</li>
|
||||
|
||||
<li><strong>development</strong> - Is Jasper used in development mode? If true,
|
||||
the frequency at which JSPs are checked for modification may be specified via
|
||||
the modificationTestInterval parameter.<code>true</code> or <code>false</code>,
|
||||
default <code>true</code>.</li>
|
||||
|
||||
<li><strong>displaySourceFragment</strong> - Should a source fragment be
|
||||
included in exception messages? <code>true</code> or <code>false</code>,
|
||||
default <code>true</code>.</li>
|
||||
|
||||
<li><strong>dumpSmap</strong> - Should the SMAP info for JSR45 debugging be
|
||||
dumped to a file? <code>true</code> or <code>false</code>, default
|
||||
<code>false</code>. <code>false</code> if suppressSmap is true.</li>
|
||||
|
||||
<li><strong>enablePooling</strong> - Determines whether tag handler pooling is
|
||||
enabled. This is a compilation option. It will not alter the behaviour of JSPs
|
||||
that have already been compiled. <code>true</code> or <code>false</code>,
|
||||
default <code>true</code>.
|
||||
</li>
|
||||
|
||||
<li><strong>engineOptionsClass</strong> - Allows specifying the Options class
|
||||
used to configure Jasper. If not present, the default EmbeddedServletOptions
|
||||
will be used. This option is ignored if running under a SecurityManager.
|
||||
</li>
|
||||
|
||||
<li><strong>errorOnUseBeanInvalidClassAttribute</strong> - Should Jasper issue
|
||||
an error when the value of the class attribute in an useBean action is not a
|
||||
valid bean class? <code>true</code> or <code>false</code>, default
|
||||
<code>true</code>.</li>
|
||||
|
||||
<li><strong>fork</strong> - Have Ant fork JSP page compiles so they are
|
||||
performed in a separate JVM from Tomcat? <code>true</code> or
|
||||
<code>false</code>, default <code>true</code>.</li>
|
||||
|
||||
<li><strong>genStringAsCharArray</strong> - Should text strings be generated as char
|
||||
arrays, to improve performance in some cases? Default <code>false</code>.</li>
|
||||
|
||||
<li><strong>ieClassId</strong> - Deprecated. Will be removed in Tomact 10.1.
|
||||
The class-id value to be sent to Internet
|
||||
Explorer when using <jsp:plugin> tags. Default
|
||||
<code>clsid:8AD9C840-044E-11D1-B3E9-00805F499D93</code>.</li>
|
||||
|
||||
<li><strong>javaEncoding</strong> - Java file encoding to use for generating
|
||||
java source files. Default <code>UTF8</code>.</li>
|
||||
|
||||
<li><strong>keepgenerated</strong> - Should we keep the generated Java source
|
||||
code for each page instead of deleting it? <code>true</code> or
|
||||
<code>false</code>, default <code>true</code>.</li>
|
||||
|
||||
<li><strong>mappedfile</strong> - Should we generate static content with one
|
||||
print statement per input line, to ease debugging?
|
||||
<code>true</code> or <code>false</code>, default <code>true</code>.</li>
|
||||
|
||||
<li><strong>maxLoadedJsps</strong> - The maximum number of JSPs that will be
|
||||
loaded for a web application. If more than this number of JSPs are loaded, the
|
||||
least recently used JSPs will be unloaded so that the number of JSPs loaded at
|
||||
any one time does not exceed this limit. A value of zero or less indicates no
|
||||
limit. Default <code>-1</code></li>
|
||||
|
||||
<li><strong>jspIdleTimeout</strong> - The amount of time in seconds a JSP can be
|
||||
idle before it is unloaded. A value of zero or less indicates never unload.
|
||||
Default <code>-1</code></li>
|
||||
|
||||
<li><strong>modificationTestInterval</strong> - Causes a JSP (and its dependent
|
||||
files) to not be checked for modification during the specified time interval
|
||||
(in seconds) from the last time the JSP was checked for modification. A value of
|
||||
0 will cause the JSP to be checked on every access. Used in development mode
|
||||
only. Default is <code>4</code> seconds.</li>
|
||||
|
||||
<li><strong>recompileOnFail</strong> - If a JSP compilation fails should the
|
||||
modificationTestInterval be ignored and the next access trigger a re-compilation
|
||||
attempt? Used in development mode only and is disabled by default as compilation
|
||||
may be expensive and could lead to excessive resource usage.</li>
|
||||
|
||||
<li><strong>scratchdir</strong> - What scratch directory should we use when
|
||||
compiling JSP pages? Default is the work directory for the current web
|
||||
application. This option is ignored if running under a SecurityManager.</li>
|
||||
|
||||
<li><strong>suppressSmap</strong> - Should the generation of SMAP info for JSR45
|
||||
debugging be suppressed? <code>true</code> or <code>false</code>, default
|
||||
<code>false</code>.</li>
|
||||
|
||||
<li><strong>trimSpaces</strong> - Should template text that consists entirely of
|
||||
whitespace be removed from the output (<code>true</code>), replaced with a
|
||||
single space (<code>single</code>) or left unchanged (<code>false</code>)?
|
||||
Alternatively, the <code>extended</code> option will remove leading and trailing
|
||||
whitespace from template text and collapse sequences of whitespace and newlines
|
||||
within the template text to a single new line. Note that if a JSP page or tag
|
||||
file specifies a <code>trimDirectiveWhitespaces</code> value of
|
||||
<code>true</code>, that will take precedence over this configuration setting for
|
||||
that page/tag. Default <code>false</code>.</li>
|
||||
|
||||
<li><strong>xpoweredBy</strong> - Determines whether X-Powered-By response
|
||||
header is added by generated servlet. <code>true</code> or <code>false</code>,
|
||||
default <code>false</code>.</li>
|
||||
|
||||
<li><strong>strictQuoteEscaping</strong> - When scriptlet expressions are used
|
||||
for attribute values, should the rules in JSP.1.6 for the escaping of quote
|
||||
characters be strictly applied? <code>true</code> or <code>false</code>, default
|
||||
<code>true</code>.</li>
|
||||
|
||||
<li><strong>quoteAttributeEL</strong> - When EL is used in an attribute value
|
||||
on a JSP page, should the rules for quoting of attributes described in JSP.1.6
|
||||
be applied to the expression? <code>true</code> or <code>false</code>, default
|
||||
<code>true</code>.</li>
|
||||
</ul>
|
||||
|
||||
<p>The Java compiler from Eclipse JDT in included as the default compiler. It is
|
||||
an advanced Java compiler which will load all dependencies from the Tomcat class
|
||||
loader, which will help tremendously when compiling on large installations with
|
||||
tens of JARs. On fast servers, this will allow sub-second recompilation cycles
|
||||
for even large JSP pages.</p>
|
||||
|
||||
<p>Apache Ant, which was used in previous Tomcat releases, can be used instead
|
||||
of the new compiler by configuring the compiler attribute as explained above.
|
||||
</p>
|
||||
|
||||
<p>If you need to change the JSP Servlet settings for an application you can
|
||||
override the default configuration by re-defining the JSP Servlet in
|
||||
<code>/WEB-INF/web.xml</code>. However, this may cause problems if you attempt
|
||||
to deploy the application on another container as the JSP Servlet class may
|
||||
not be recognised. You can work-around this problem by using the Tomcat specific
|
||||
<code>/WEB-INF/tomcat-web.xml</code> deployment descriptor. The format is
|
||||
identical to <code>/WEB-INF/web.xml</code>. It will override any default
|
||||
settings but not those in <code>/WEB-INF/web.xml</code>. Since it is Tomcat
|
||||
specific, it will only be processed when the application is deployed on
|
||||
Tomcat.</p>
|
||||
|
||||
</div><h3 id="Known_issues">Known issues</h3><div class="text">
|
||||
|
||||
<p>As described in
|
||||
<a href="https://bz.apache.org/bugzilla/show_bug.cgi?id=39089">
|
||||
bug 39089</a>, a known JVM issue,
|
||||
<a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6294277">
|
||||
bug 6294277</a>, may cause a
|
||||
<code>java.lang.InternalError: name is too long to represent</code> exception
|
||||
when compiling very large JSPs. If this is observed then it may be worked around
|
||||
by using one of the following:
|
||||
</p>
|
||||
<ul>
|
||||
<li>reduce the size of the JSP</li>
|
||||
<li>disable SMAP generation and JSR-045 support by setting
|
||||
<code>suppressSmap</code> to <code>true</code>.</li>
|
||||
</ul>
|
||||
|
||||
</div><h3 id="Production_Configuration">Production Configuration</h3><div class="text">
|
||||
|
||||
<p>The main JSP optimization which can be done is precompilation of JSPs.
|
||||
However, this might not be possible (for example, when using the
|
||||
jsp-property-group feature) or practical, in which case the configuration of the
|
||||
Jasper servlet becomes critical.</p>
|
||||
|
||||
<p>When using Jasper 2 in a production Tomcat server you should consider making
|
||||
the following changes from the default configuration.</p>
|
||||
<ul>
|
||||
<li><strong>development</strong> - To disable on access checks for JSP
|
||||
pages compilation set this to <code>false</code>.</li>
|
||||
<li><strong>genStringAsCharArray</strong> - To generate slightly more efficient
|
||||
char arrays, set this to <code>true</code>.</li>
|
||||
<li><strong>modificationTestInterval</strong> - If development has to be set to
|
||||
<code>true</code> for any reason (such as dynamic generation of JSPs), setting
|
||||
this to a high value will improve performance a lot.</li>
|
||||
<li><strong>trimSpaces</strong> - To remove unnecessary bytes from the response,
|
||||
consider setting this to <code>single</code> or <code>extended</code>.</li>
|
||||
</ul>
|
||||
|
||||
</div><h3 id="Web_Application_Compilation">Web Application Compilation</h3><div class="text">
|
||||
|
||||
<p>Using Ant is the preferred way to compile web applications using JSPC. Note
|
||||
that when pre-compiling JSPs, SMAP information will only be included in the
|
||||
final classes if suppressSmap is false and compile is true.
|
||||
Use the script given below (a similar script is included in the "deployer"
|
||||
download) to precompile a webapp:
|
||||
</p>
|
||||
|
||||
<div class="codeBox"><pre><code><project name="Webapp Precompilation" default="all" basedir=".">
|
||||
|
||||
<import file="${tomcat.home}/bin/catalina-tasks.xml"/>
|
||||
|
||||
<target name="jspc">
|
||||
|
||||
<jasper
|
||||
validateXml="false"
|
||||
uriroot="${webapp.path}"
|
||||
webXmlInclude="${webapp.path}/WEB-INF/generated_web.xml"
|
||||
outputDir="${webapp.path}/WEB-INF/src" />
|
||||
|
||||
</target>
|
||||
|
||||
<target name="compile">
|
||||
|
||||
<mkdir dir="${webapp.path}/WEB-INF/classes"/>
|
||||
<mkdir dir="${webapp.path}/WEB-INF/lib"/>
|
||||
|
||||
<javac destdir="${webapp.path}/WEB-INF/classes"
|
||||
debug="on" failonerror="false"
|
||||
srcdir="${webapp.path}/WEB-INF/src"
|
||||
excludes="**/*.smap">
|
||||
<classpath>
|
||||
<pathelement location="${webapp.path}/WEB-INF/classes"/>
|
||||
<fileset dir="${webapp.path}/WEB-INF/lib">
|
||||
<include name="*.jar"/>
|
||||
</fileset>
|
||||
<pathelement location="${tomcat.home}/lib"/>
|
||||
<fileset dir="${tomcat.home}/lib">
|
||||
<include name="*.jar"/>
|
||||
</fileset>
|
||||
<fileset dir="${tomcat.home}/bin">
|
||||
<include name="*.jar"/>
|
||||
</fileset>
|
||||
</classpath>
|
||||
<include name="**" />
|
||||
<exclude name="tags/**" />
|
||||
</javac>
|
||||
|
||||
</target>
|
||||
|
||||
<target name="all" depends="jspc,compile">
|
||||
</target>
|
||||
|
||||
<target name="cleanup">
|
||||
<delete>
|
||||
<fileset dir="${webapp.path}/WEB-INF/src"/>
|
||||
<fileset dir="${webapp.path}/WEB-INF/classes/org/apache/jsp"/>
|
||||
</delete>
|
||||
</target>
|
||||
|
||||
</project></code></pre></div>
|
||||
|
||||
<p>
|
||||
The following command line can be used to run the script
|
||||
(replacing the tokens with the Tomcat base path and the path to the webapp
|
||||
which should be precompiled):
|
||||
</p>
|
||||
<div class="codeBox"><pre><code>$ANT_HOME/bin/ant -Dtomcat.home=<$TOMCAT_HOME> -Dwebapp.path=<$WEBAPP_PATH></code></pre></div>
|
||||
|
||||
|
||||
<p>
|
||||
Then, the declarations and mappings for the servlets which were generated
|
||||
during the precompilation must be added to the web application deployment
|
||||
descriptor. Insert the <code>${webapp.path}/WEB-INF/generated_web.xml</code>
|
||||
at the right place inside the <code>${webapp.path}/WEB-INF/web.xml</code> file.
|
||||
Restart the web application (using the manager) and test it to verify it is
|
||||
running fine with precompiled servlets. An appropriate token placed in the
|
||||
web application deployment descriptor may also be used to automatically
|
||||
insert the generated servlet declarations and mappings using Ant filtering
|
||||
capabilities. This is actually how all the webapps distributed with Tomcat
|
||||
are automatically compiled as part of the build process.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
At the jasper task you can use the option <code>addWebXmlMappings</code> for
|
||||
automatic merge the <code>${webapp.path}/WEB-INF/generated_web.xml</code>
|
||||
with the current web application deployment descriptor at
|
||||
<code>${webapp.path}/WEB-INF/web.xml</code>.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
When you want to use a specific version of Java for your JSP's, add the
|
||||
javac compiler task attributes <code>source</code> and <code>target</code> with
|
||||
appropriate values. For example, <code>16</code> to compile JSPs for Java 16.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
For production you may wish to disable debug info with
|
||||
<code>debug="off"</code>.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
When you don't want to stop the JSP generation at first JSP syntax error, use
|
||||
<code>failOnError="false"</code> and with
|
||||
<code>showSuccess="true"</code> all successful <i>JSP to Java</i>
|
||||
generation are printed out. Sometimes it is very helpful, when you cleanup the
|
||||
generate java source files at <code>${webapp.path}/WEB-INF/src</code>
|
||||
and the compile JSP servlet classes at
|
||||
<code>${webapp.path}/WEB-INF/classes/org/apache/jsp</code>.
|
||||
</p>
|
||||
|
||||
<p><strong>Hints:</strong></p>
|
||||
<ul>
|
||||
<li> When you switch to another Tomcat release, then regenerate and recompile
|
||||
your JSP's with the new Tomcat version.</li>
|
||||
<li>Use java system property at server runtime to disable PageContext pooling
|
||||
<code>org.apache.jasper.runtime.JspFactoryImpl.USE_POOL=false</code>.
|
||||
and limit the buffering with
|
||||
<code>org.apache.jasper.runtime.BodyContentImpl.LIMIT_BUFFER=true</code>. Note
|
||||
that changing from the defaults may affect performance, but it will vary
|
||||
depending on the application.</li>
|
||||
</ul>
|
||||
</div><h3 id="Optimisation">Optimisation</h3><div class="text">
|
||||
<p>
|
||||
There are a number of extension points provided within Jasper that enable the
|
||||
user to optimise the behaviour for their environment.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
The first of these extension points is the tag plug-in mechanism. This allows
|
||||
alternative implementations of tag handlers to be provided for a web application
|
||||
to use. Tag plug-ins are registered via a <code>tagPlugins.xml</code> file
|
||||
located under <code>WEB-INF</code>. A sample plug-in for the JSTL is included
|
||||
with Jasper.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
The second extension point is the Expression Language interpreter. Alternative
|
||||
interpreters may be configured through the <code>ServletContext</code>. See the
|
||||
<code>ELInterpreterFactory</code> javadoc for details of how to configure an
|
||||
alternative EL interpreter. A alternative interpreter primarily targeting tag
|
||||
settings is provided at
|
||||
<code>org.apache.jasper.optimizations.ELInterpreterTagSetters</code>. See the
|
||||
javadoc for details of the optimisations and the impact they have on
|
||||
specification compliance.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
An extension point is also provided for coercion of String values to Enums. It
|
||||
is provided at
|
||||
<code>org.apache.jasper.optimizations.StringInterpreterEnum</code>. See the
|
||||
javadoc for details of the optimisations and the impact they have on
|
||||
specification compliance.
|
||||
</p>
|
||||
</div></div></div></div></div><footer><div id="footer">
|
||||
Copyright © 1999-2023, The Apache Software Foundation
|
||||
</div></footer></div></body></html>
|
||||
Reference in New Issue
Block a user