First, we'll download and extract the zip package. By browsing the download site of Tomcat 8, we. The Apache Tomcat ® software is an open source implementation of the Jakarta Servlet, Jakarta Server Pages, Jakarta Expression Language, Jakarta WebSocket, Jakarta Annotations and Jakarta Authentication specifications. These specifications are part of the Jakarta EE platform. The Jakarta EE platform is the evolution of the Java EE platform. Tomcat 10 and later implement specifications.
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Default Servlet Reference
Table of Contents
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What is the DefaultServlet
The default servlet is the servlet which serves static resources as wellas serves the directory listings (if directory listings are enabled).
Where is it declared?
It is declared globally in $CATALINA_BASE/conf/web.xml.By default here is it's declaration:
So by default, the default servlet is loaded at webapp startup anddirectory listings are disabled and debugging is turned off.What can I change?
The DefaultServlet allows the following initParameters: Tomcat 11.
Property | Description |
---|---|
debug | Debugging level. It is not very useful unless you are a tomcat developer. As of this writing, useful values are 0, 1, 11. [0] |
listings | If no welcome file is present, can a directory listing be shown? value may be true or false [false] Welcome files are part of the servlet api. WARNING: Listings of directories containing many entries are expensive. Multiple requests for large directory listings can consume significant proportions of server resources. |
precompressed | If a precompressed version of a file exists (a file with .br or .gz appended to the file name located alongside the original file), Tomcat will serve the precompressed file if the user agent supports the matching content encoding (br or gzip) and this option is enabled. [false] The precompressed file with the with .br or .gz extension will be accessible if requested directly so if the original resource is protected with a security constraint, the precompressed versions must be similarly protected. It is also possible to configure the list of precompressed formats. The syntax is comma separated list of [content-encoding]=[file-extension] pairs. For example: br=.br,gzip=.gz,bzip2=.bz2 . If multiple formats are specified, the client supports more than one and the client does not express a preference, the order of the list of formats will be treated as the server preference order and used to select the format returned. |
readmeFile | If a directory listing is presented, a readme file may also be presented with the listing. This file is inserted as is so it may contain HTML. |
globalXsltFile | If you wish to customize your directory listing, you can use an XSL transformation. This value is a relative file name (to either $CATALINA_BASE/conf/ or $CATALINA_HOME/conf/) which will be used for all directory listings. This can be overridden per context and/or per directory. See contextXsltFile and localXsltFile below. The format of the xml is shown below. |
contextXsltFile | You may also customize your directory listing by context by configuring contextXsltFile . This must be a context relative path (e.g.: /path/to/context.xslt ) to a file with a .xsl or .xslt extension. This overrides globalXsltFile . If this value is present but a file does not exist, then globalXsltFile will be used. If globalXsltFile does not exist, then the default directory listing will be shown. |
localXsltFile | You may also customize your directory listing by directory by configuring localXsltFile . This must be a file in the directory where the listing will take place to with a .xsl or .xslt extension. This overrides globalXsltFile and contextXsltFile . If this value is present but a file does not exist, then contextXsltFile will be used. If contextXsltFile does not exist, then globalXsltFile will be used. If globalXsltFile does not exist, then the default directory listing will be shown. |
input | Input buffer size (in bytes) when reading resources to be served. [2048] |
output | Output buffer size (in bytes) when writing resources to be served. [2048] |
readonly | Is this context 'read only', so HTTP commands like PUT and DELETE are rejected? [true] |
fileEncoding | File encoding to be used when reading static resources. [platform default] |
sendfileSize | If the connector used supports sendfile, this represents the minimal file size in KB for which sendfile will be used. Use a negative value to always disable sendfile. [48] |
useAcceptRanges | If true, the Accept-Ranges header will be set when appropriate for the response. [true] |
showServerInfo | Should server information be presented in the response sent to clients when directory listing is enabled. [true] |
sortListings | Should the server sort the listings in a directory. [false] |
sortDirectoriesFirst | Should the server list all directories before all files. [false] |
How do I customize directory listings?
You can override DefaultServlet with you own implementation and use thatin your web.xml declaration. If youcan understand what was just said, we will assume you can read the codeto DefaultServlet servlet and make the appropriate adjustments. (If not,then that method isn't for you)
You can use either
localXsltFile
orglobalXsltFile
and DefaultServlet will createan xml document and run it through an xsl transformation basedon the values provided in localXsltFile
andglobalXsltFile
. localXsltFile
is firstchecked, followed by globalXsltFile
, then defaultbehaviors takes place.Apache Tomcat/8.0.32
Format:
- size will be missing if
type='dir'
- Readme is a CDATA entry
Apache Tomcat 8 Eol
The following is a sample xsl file which mimics the default tomcat behavior:
How do I secure directory listings?
Apache Tomcat 8 End Of Life
Use web.xml in each individual webapp. See the security section of theServlet specification.