System Properties

Introduction

The follow sections list the system properties that may be set to modify the default Tomcat behaviour.

Servlet container and connectors

Attribute	Description
`catalina.useNaming`	If this is `false` it will override the `useNaming` attribute for all Context elements.
`jvmRoute`	Provides a default value for the `jvmRoute` attribute of the Engine element. It does not override the a value configured on the Engine element.
`org.apache.catalina.loader. WebappClassLoader.ENABLE_CLEAR_REFERENCES`	If `true`, 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. There have been some issues reported with log4j when this option is `true`. Applications without memory leaks using recent JVMs should operate correctly with this option set to `false`. If not specified, the default value of `true` will be used.
`catalina.config`	The URL for the catalina.properties configuration file.
`org.apache.tomcat.tomcat.util.buf.StringCache.byte.enabled`	If `true`, the String cache is enabled for `ByteChunk`. If not specified, the default value of `false` will be used.
`org.apache.tomcat.tomcat.util.buf.StringCache.char.enabled`	If `true`, the String cache is enabled for `CharChunk`. If not specified, the default value of `false` will be used.
`org.apache.tomcat.tomcat.util.buf.StringCache.trainThreshold`	The number of times `toString()` must be called before the cache is activated. If not specified, the default value of `20000` will be used.
`org.apache.tomcat.tomcat.util.buf.StringCache.cacheSize`	The size of the String cache. If not specified, the default value of `200` will be used.
`org.apache.tomcat.tomcat.util.buf.StringCache.maxStringSize`	The maximum length of String that will be cached. If not specified, the default value of `128` will be used.
`org.apache.tomcat.util. http.FastHttpDateFormat.CACHE_SIZE`	The size of the cache to use parsed and formatted date value. If not specified, the default value of `1000` will be used.
`org.apache.catalina.core. StandardService.DELAY_CONNECTOR_STARTUP`	If `true`, the connector startup will not be done automatically. Useful in embedded mode.
`org.apache.catalina.connector. Request.SESSION_ID_CHECK`	If `true`, the Servet container will verify that a session exists in a context with the specified session id before creating a session with that id.
`org.apache.coyote. USE_CUSTOM_STATUS_MSG_IN_HEADER`	If this is `true` custom HTTP status messages will be used within HTTP headers. Users must ensure that any such message is ISO-8859-1 encoded, particularly if user provided input is included in the message, to prevent a possible XSS vulnerability. If not specified the default value of `false` will be used.
`org.apache.tomcat.util. http.ServerCookie.VERSION_SWITCH`	If using cookie values which have to be quoted to be valid and v0 cookies, this will cause an automatic switch to v1 cookies. If not specified, the default value of `true` will be used.

EL

Attribute	Description
`org.apache.el.parser.COERCE_TO_ZERO`	If `true`, when coercing expressions to numbers `""` and `null` will be coerced to zero as required by the specification. If not specified, the default value of `true` will be used.

JSP

Attribute	Description
`org.apache.jasper.compiler. Generator.VAR_EXPRESSIONFACTORY`	The name of the variable to use for the expression language expression factory. If not specified, the default value of `_el_expressionfactory` will be used.
`org.apache.jasper.compiler. Generator.VAR_INSTANCEMANAGER`	The name of the variable to use for the instance manager factory. If not specified, the default value of `_jsp_instancemanager` will be used.
`org.apache.jasper.compiler. Parser.STRICT_QUOTE_ESCAPING`	If `false` the requirements for escpaing quotes in JSP attributes will be relaxed so that a missing required quote will not cause an error. If not specified, the specification compliant default of `true` will be used.
`org.apache.jasper.runtime. JspFactoryImpl.USE_POOL`	If `true`, a ThreadLocal `PageContext` pool will be used. If not specified, the default value of `true` will be used.
`org.apache.jasper.runtime. JspFactoryImpl.POOL_SIZE`	The size of the ThreadLocal `PageContext`. If not specified, the default value of `8` will be used.
`org.apache.jasper.Constants. JSP_SERVLET_BASE`	The base class of the Servlets generated from the JSPs. If not specified, the default value of `org.apache.jasper.runtime.HttpJspBase` will be used.
`org.apache.jasper.Constants. SERVICE_METHOD_NAME`	The name of the service method called by the base class. If not specified, the default value of `_jspService` will be used.
`org.apache.jasper.Constants. SERVLET_CLASSPATH`	The name of the ServletContext attribute that provides the classpath for the JSP. If not specified, the default value of `org.apache.catalina.jsp_classpath` will be used.
`org.apache.jasper.Constants. JSP_FILE`	The name of the request attribute for `<jsp-file>` element of a servlet definition. If present on a request, this overrides the value returned by `request.getServletPath()` to select the JSP page to be executed. If not specified, the default value of `org.apache.catalina.jsp_file` will be used.
`org.apache.jasper.Constants. PRECOMPILE`	The name of the query parameter that causes the JSP engine to just pregenerate the servlet but not invoke it. If not specified, the default value of `org.apache.catalina.jsp_precompile` will be used.
`org.apache.jasper.Constants. JSP_PACKAGE_NAME`	The default package name for compiled jsp pages. If not specified, the default value of `org.apache.jsp` will be used.
`org.apache.jasper.Constants. TAG_FILE_PACKAGE_NAME`	The default package name for tag handlers generated from tag files. If not specified, the default value of `org.apache.jsp.tag` will be used.
`org.apache.jasper.Constants. ALT_DD_ATTR`	The servlet context attribute under which the alternate deployment descriptor for this web application is stored. If not specified, the default value of `org.apache.catalina.deploy.alt_dd` will be used.
`org.apache.jasper.Constants. TEMP_VARIABLE_NAME_PREFIX`	Prefix to use for generated temporary variable names. If not specified, the default value of `_jspx_temp` will be used.
`org.apache.jasper.Constants. USE_INSTANCE_MANAGER_FOR_TAGS`	If `true`, the instance manager is used to obtain tag handler instances. If not specified, `false` will be used.
`org.apache.jasper.Constants. USE_INSTANCE_MANAGER_FOR_TAGS`	If `true`, annotations specified in tags will be processed and injected. This can have a performance impact when using simple tags, or if tag pooling is disabled. If not specified, `true` will be used.

Security

Attribute	Description
`org.apache.catalina.connector. RECYCLE_FACADES`	If this is `true` or if a security manager is in use a new facade object will be created for each request. If not specified, the default value of `false` will be used.
`org.apache.catalina.connector. CoyoteAdapter.ALLOW_BACKSLASH`	If this is `true` the '\' character will be permitted as a path delimiter. If not specified, the default value of `false` will be used.
`org.apache.tomcat.util.buf. UDecoder.ALLOW_ENCODED_SLASH`	If this is `true` '%2F' and '%5C' will be permitted as path delimiters. If not specified, the default value of `false` will be used.

Specification

Attribute	Description
`org.apache.catalina. STRICT_SERVLET_COMPLIANCE`	If this is `true` the following actions will occur: 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) a call to `Response.getWriter()` if no character encoding has been specified will result in subsequent calls to `Response.getCharacterEncoding()` returning `ISO-8859-1` and the `Content-Type` response header will include a `charset=ISO-8859-1` component. (SRV.15.2.22.1) 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 explicity accesses the session. (SRV.7.6)
`org.apache.catalina.core. StandardWrapperValve.SERVLET_STATS`	If `true` or if `org.apache.catalina.STRICT_SERVLET_COMPLIANCE` is `true`, the wrapper will collect the JSR-77 statistics for individual servlets. If not specified, the default value of `false` will be used.
`org.apache.catalina.session. StandardSession.ACTIVITY_CHECK`	If this is `true` or if `org.apache.catalina.STRICT_SERVLET_COMPLIANCE` is `true` 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. If not specified, the default value of `false` will be used.