<?xml version="1.0"?>
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<!DOCTYPE document [
  <!ENTITY project SYSTEM "project.xml">
]>
<document url="systemprops.html">

  &project;

  <properties>
    <title>System Properties</title>
  </properties>

<body>

<section name="Table of Contents">
<toc/>
</section>

<section name="Introduction">
  <p>The following sections list the system properties that may be set to modify
  the default Tomcat behaviour.</p>
</section>



<section name="Clustering">
  <properties>

    <property name="org.apache.catalina. tribes.dns_lookups">
      <p>If <code>true</code>, the clustering module will attempt to use DNS to
      resolve any host names provided in the cluster configuration.</p>
      <p>If not specified, the default value of <code>false</code> will be used.</p>
    </property>

  </properties>

</section>

<section name="Expression Language">
  <properties>

    <property name="org.apache.el.BeanELResolver. CACHE_SIZE">
      <p>The number of javax.el.BeanELResolver.BeanProperties objects that will
      be cached by the EL Parser.</p>
      <p>If not specified, the default of <code>1000</code> will be used.</p>
    </property>

    <property name="org.apache.el.ExpressionBuilder. CACHE_SIZE">
      <p>The number of parsed EL expressions that will be cached by the EL
      Parser.</p>
      <p>If not specified, the default of <code>5000</code> will be used.</p>
    </property>

    <property name="org.apache.el.parser. COERCE_TO_ZERO">
      <p>If <code>true</code>, when coercing EL expressions to numbers
      <code>""</code> and <code>null</code> will be coerced to zero as required
      by the specification.</p>
      <p>If not specified, the default value of <code>true</code> will be used.</p>
    </property>

    <property name="org.apache.el.parser. SKIP_IDENTIFIER_CHECK">
      <p>If <code>true</code>, when parsing EL expressions, identifiers will not be
      checked to ensure that they conform to the Java Language Specification for
      Java identifiers.</p>
      <p>If not specified, the default value of <code>true</code> will be used.</p>
    </property>

  </properties>
</section>

<section name="Jasper">
  <properties>

    <property name="org.apache.jasper.compiler. Generator.VAR_EXPRESSIONFACTORY">
      <p>The name of the variable to use for the expression language expression
      factory.</p>
      <p>If not specified, the default value of <code>_el_expressionfactory</code>
      will be used.</p>
    </property>

    <property name="org.apache.jasper.compiler. Generator.VAR_INSTANCEMANAGER">
      <p>The name of the variable to use for the instance manager factory.</p>
      <p>If not specified, the default value of <code>_jsp_instancemanager</code>
      will be used.</p>
    </property>

    <property name="org.apache.jasper.compiler. Generator.STRICT_GET_PROPERTY">
      <p>If <code>true</code>, the requirement to have the object referenced in
      <code>jsp:getProperty</code> action to be previously "introduced"
      to the JSP processor, as specified in the chapter JSP.5.3 of JSP 2.0 and
      later specifications, is enforced.</p>
      <p>If not specified, the specification compliant default of <code>true</code>
      will be used.</p>
    </property>

    <property name="org.apache.jasper.compiler. Parser.STRICT_QUOTE_ESCAPING">
      <p>If <code>false</code> the requirements for escaping quotes in JSP
      attributes will be relaxed so that an unescaped quote will not
      cause an error.</p>
      <p>If not specified, the specification compliant default of
      <code>true</code> will be used.</p>
    </property>

    <property name="org.apache.jasper.runtime. BodyContentImpl.LIMIT_BUFFER">
      <p>If <code>true</code>, any tag buffer that expands beyond
      <code>org.apache.jasper.Constants.DEFAULT_TAG_BUFFER_SIZE</code> will be
      destroyed and a new buffer created of the default size.</p>
      <p>If not specified, the default value of <code>false</code> will be used.</p>
    </property>

    <property name="org.apache.jasper.runtime. JspFactoryImpl.USE_POOL">
      <p>If <code>true</code>, a ThreadLocal <code>PageContext</code> pool will
      be used.</p>
      <p>If not specified, the default value of <code>true</code> will be used.</p>
    </property>

    <property name="org.apache.jasper.runtime. JspFactoryImpl.POOL_SIZE">
      <p>The size of the ThreadLocal <code>PageContext</code>.</p>
      <p>If not specified, the default value of <code>8</code> will be used.</p>
    </property>

    <property name="org.apache.jasper.Constants. JSP_SERVLET_BASE">
      <p>The base class of the Servlets generated from the JSPs.</p>
      <p>If not specified, the default value of
      <code>org.apache.jasper.runtime.HttpJspBase</code> will be used.</p>
    </property>

    <property name="org.apache.jasper.Constants. SERVICE_METHOD_NAME">
      <p>The name of the service method called by the base class.</p>
      <p>If not specified, the default value of <code>_jspService</code>
      will be used.</p>
    </property>

    <property name="org.apache.jasper.Constants. SERVLET_CLASSPATH">
      <p>The name of the ServletContext attribute that provides the classpath
      for the JSP.</p>
      <p>If not specified, the default value of
      <code>org.apache.catalina.jsp_classpath</code> will be used.</p>
    </property>

    <property name="org.apache.jasper.Constants. JSP_FILE">
      <p>The name of the request attribute for <code>&lt;jsp-file&gt;</code>
      element of a servlet definition. If present on a request, this overrides
      the value returned by <code>request.getServletPath()</code> to select the
      JSP page to be executed.</p>
      <p>If not specified, the default value of
      <code>org.apache.catalina.jsp_file</code> will be used.</p>
    </property>

    <property name="org.apache.jasper.Constants. PRECOMPILE">
      <p>The name of the query parameter that causes the JSP engine to just
      pregenerate the servlet but not invoke it.</p>
      <p>If not specified, the default value of <code>jsp_precompile</code>
      will be used, as defined by JSP specification (JSP.11.4.2).</p>
    </property>

    <property name="org.apache.jasper.Constants. JSP_PACKAGE_NAME">
      <p>The default package name for compiled jsp pages.</p>
      <p>If not specified, the default value of <code>org.apache.jsp</code>
      will be used.</p>
    </property>

    <property name="org.apache.jasper.Constants. TAG_FILE_PACKAGE_NAME">
      <p>The default package name for tag handlers generated from tag files.</p>
      <p>If not specified, the default value of <code>org.apache.jsp.tag</code>
      will be used.</p>
    </property>

    <property name="org.apache.jasper.Constants. ALT_DD_ATTR">
      <p>The servlet context attribute under which the alternate deployment
      descriptor for this web application is stored.</p>
      <p>If not specified, the
      default value of <code>org.apache.catalina.deploy.alt_dd</code> will
      be used.</p>
    </property>

    <property name="org.apache.jasper.Constants. TEMP_VARIABLE_NAME_PREFIX">
      <p>Prefix to use for generated temporary variable names.</p>
      <p>If not specified,
      the default value of <code>_jspx_temp</code> will be used.</p>
    </property>

    <property name="org.apache.jasper.Constants. USE_INSTANCE_MANAGER_FOR_TAGS">
      <p>If <code>true</code>, the instance manager is used to obtain tag
      handler instances.</p>
      <p>If not specified, the default value of <code>false</code> will be used.</p>
    </property>

  </properties>

</section>


<section name="Security">

  <properties>

    <property name="org.apache.catalina.connector. RECYCLE_FACADES">
      <p>If this is <code>true</code> or if a security manager is in use a new
      facade object will be created for each request.</p>
      <p>If not specified, the
      default value of <code>false</code> will be used.</p>
    </property>

    <property
    name="org.apache.catalina.connector. CoyoteAdapter.ALLOW_BACKSLASH">
      <p>If this is <code>true</code> the '\' character will be permitted as a
      path delimiter.</p>
      <p>If not specified, the default value of <code>false</code>
      will be used.</p>
    </property>

    <property
    name="org.apache.tomcat.util.buf. UDecoder.ALLOW_ENCODED_SLASH">
      <p>If this is <code>true</code> '%2F' and '%5C' will be permitted as path
      delimiters.</p>
      <p>If not specified, the default value of <code>false</code> will
      be used.</p>
    </property>

    <property
    name="org.apache.coyote. USE_CUSTOM_STATUS_MSG_IN_HEADER"><p>If this is
      <code>true</code>, custom HTTP status messages will be used within HTTP
      headers. If a custom message is specified that is not valid for use in an
      HTTP header (as defined by RFC2616) then the custom message will be
      ignored and the default message used.</p>
      <p>If not specified, the default value of <code>false</code> will be used.</p>
    </property>

  </properties>

</section>


<section name="Specification">

  <properties>

    <property name="org.apache.catalina. STRICT_SERVLET_COMPLIANCE">
      <p>If this is <code>true</code> the following actions will occur:
      <ul>
      <li>any wrapped request or response object passed to an application
      dispatcher will be checked to ensure that it has wrapped the original
      request or response. (SRV.8.2 / SRV.14.2.5.1)
      </li>
      <li>a call to <code>Response.getWriter()</code> if no character encoding
      has been specified will result in subsequent calls to
      <code>Response.getCharacterEncoding()</code> returning
      <code>ISO-8859-1</code> and the <code>Content-Type</code> response header
      will include a <code>charset=ISO-8859-1</code> component. (SRV.15.2.22.1)
      </li>
      <li>every request that is associated with a session will cause the
      session's last accessed time to be updated regardless of whether or not
      the request explicitly accesses the session. (SRV.7.6)  
      </li>
      <li>
        cookies will be parsed strictly, by default v0 cookies will not work with any invalid characters.
        <br/>If set to <code>false</code>, any v0 cookie with invalid character
        will be switched to a v1 cookie and the value will be quoted.
      </li>
      <li>
        the path in <code>ServletContext.getResource</code> /
        <code>getResourceAsStream</code> calls must start with a "/".<br/>
        If set to <code>false</code>, code like <code>getResource("myfolder/myresource.txt")</code> will work.
      </li>
      </ul>
      </p>
      <p>If this is <code>true</code> the default value will be changed for:
      <ul>
      <li><code>org.apache.catalina.connector.Request. ALLOW_EMPTY_QUERY_STRING</code> property</li>
      </ul>
      </p>
      <p>If not specified, the default value of <code>false</code> will be used.</p>
    </property>

    <property
        name="org.apache.catalina.connector. Request.ALLOW_EMPTY_QUERY_STRING">
      <p>If this is <code>true</code> Tomcat will return an empty string rather
      than <code>null</code> for empty query strings - i.e. query strings where
      only <code>?</code> is present.</p>
      <p>If not specified, the value of
      <code>org.apache.catalina.STRICT_SERVLET_COMPLIANCE</code> will be used as
      the default.</p> 
    </property>

    <property
        name="org.apache.catalina.session. StandardSession.ACTIVITY_CHECK">
      <p>If this is <code>true</code> or if
      <code>org.apache.catalina.STRICT_SERVLET_COMPLIANCE</code> is
      <code>true</code> Tomcat will track the number of active requests for each
      session. When determining if a session is valid, any session with at least
      one active request will always be considered valid.</p>
      <p>If not specified, the default value of <code>false</code> will be used.</p>
    </property>

    <property
    name="org.apache.tomcat.util.http. ServerCookie.ALLOW_EQUALS_IN_VALUE">
      <p>If this is <code>true</code> Tomcat will allow '<code>=</code>'
      characters when parsing unquoted cookie values. If <code>false</code>,
      cookie values containing '<code>=</code>' will be terminated when the
      '<code>=</code>' is encountered and the remainder of the cookie value will
      be dropped.</p>
      <p>If not specified, the default specification compliant value of
      <code>false</code> will be used.</p>
    </property>

    <property
    name="org.apache.tomcat.util.http. ServerCookie.ALWAYS_ADD_EXPIRES">
      <p>If this is <code>true</code> Tomcat will always add an expires
      parameter to a SetCookie header even for cookies with version greater than
      zero. This is to work around a known IE6 and IE7 bug that causes IE to
      ignore the Max-Age parameter in a SetCookie header.</p>
      <p>If not specified, the default value of <code>true</code> will be used.</p>
    </property>

  </properties>

</section>


<section name="Sessions">

  <properties>

    <property name="org.apache.catalina.SESSION_COOKIE_NAME">
      <p>An alternative name for the session cookie. Defaults to
      <code>JSESSIONID</code>. Note that the Servlet specification requires
      this to be <code>JSESSIONID</code>. You should not rely on being able to
      change this.</p>
    </property>

    <property name="org.apache.catalina.SESSION_PARAMETER_NAME">
      <p>An alternative name for the session path parameter. Defaults to
      <code>jsessionid</code>. Note that the Servlet specification requires
      this to be <code>jsessionid</code>. You should not rely on being able to
      change this.</p>
    </property>

    <property name="org.apache.catalina.SSO_SESSION_COOKIE_NAME">
      <p>An alternative name for the single sign on session cookie. Defaults to
      <code>JSESSIONIDSSO</code>.</p>
    </property>
    
  </properties>

</section>


<section name="Other">

  <properties>

    <property name="org.apache.coyote.MAX_TRAILER_SIZE">
      <p>Limits the total length of trailing headers in the last chunk of
      a chunked HTTP request.
      If the value is <code>-1</code>, no limit will be imposed.</p>
      <p>If not specified, the default value of <code>8192</code> will be used.</p>
    </property>

    <property name="catalina.useNaming">
      <p>If this is <code>false</code> it will override the
      <code>useNaming</code> attribute for all <a href="context.html">
      Context</a> elements.</p>
    </property>

    <property name="jvmRoute">
      <p>Provides a default value for the <code>jvmRoute</code> attribute of the
      <a href="engine.html">Engine</a> element. It does not override the value
      configured on the <a href="engine.html">Engine</a> element.</p>
    </property>

    <property
    name="org.apache.catalina.loader. WebappClassLoader.ENABLE_CLEAR_REFERENCES">
      <p>If <code>true</code>, Tomcat attempts to null out any static or final
      fields from loaded classes when a web application is stopped as a work
      around for apparent garbage collection bugs and application coding errors.
      </p>
      <p>There have been some issues reported with log4j when this option is
      <code>true</code>.</p>
      <p>Applications without memory leaks using recent JVMs should operate
      correctly with this option set to <code>false</code>.</p>
      <p>If not specified, the default value of <code>true</code> will be used.
      </p>
    </property>

    <property name="catalina.config">
      <p>The URL for the catalina.properties configuration file.</p>
    </property>

    <property name="tomcat.util.buf.StringCache.byte.enabled">
      <p>If <code>true</code>, the String cache is enabled for
      <code>ByteChunk</code>.</p>
      <p>If not specified, the default value of <code>false</code> will be used.</p>
    </property>

    <property name="tomcat.util.buf.StringCache.char.enabled">
      <p>If <code>true</code>, the String cache is enabled for
      <code>CharChunk</code>.</p>
      <p>If not specified, the default value of <code>false</code> will be used.</p>
    </property>

    <property name="tomcat.util.buf.StringCache.trainThreshold">
      <p>The number of times <code>toString()</code> must be called before the
      cache is activated.</p>
      <p>If not specified, the default value of <code>20000</code> will be used.</p>
    </property>

    <property name="tomcat.util.buf.StringCache.cacheSize">
      <p>The size of the String cache.</p>
      <p>If not specified, the default value of <code>200</code> will be used.</p>
    </property>

    <property name="tomcat.util.buf.StringCache.maxStringSize">
      <p>The maximum length of String that will be cached.</p>
      <p>If not specified, the default value of <code>128</code> will be used.</p>
    </property>

    <property name="org.apache.tomcat.util. http.FastHttpDateFormat.CACHE_SIZE">
      <p>The size of the cache to use parsed and formatted date value.</p>
      <p>If not specified, the default value of <code>1000</code> will be used.</p>
    </property>

    <property name="org.apache.tomcat.util. net.NioSelectorShared">
      <p>If <code>true</code>, use a shared selector for servlet write/read.</p>
      <p>If not specified, the default value of <code>true</code> will be used.</p>
    </property>
    
    <property name="org.apache.catalina.startup. EXIT_ON_INIT_FAILURE">
      <p>If <code>true</code>, the server will exit if an exception happens
         during the server initialization phase.</p>
      <p>If not specified, the default value of <code>false</code> will be used.</p>
    </property>

  </properties>

</section>


</body>
</document>
