Class DefaultServlet

  • All Implemented Interfaces:
    Serializable, Servlet, ServletConfig
    Direct Known Subclasses:
    WebdavServlet

    public class DefaultServlet
    extends HttpServlet

    The default resource-serving servlet for most web applications, used to serve static resources such as HTML pages and images.

    This servlet is intended to be mapped to / e.g.:

       <servlet-mapping>
           <servlet-name>default</servlet-name>
           <url-pattern>/</url-pattern>
       </servlet-mapping>
     

    It can be mapped to sub-paths, however in all cases resources are served from the web application resource root using the full path from the root of the web application context.
    e.g. given a web application structure:

     /context
       /images
         tomcat2.jpg
       /static
         /images
           tomcat.jpg
     

    ... and a servlet mapping that maps only /static/* to the default servlet:

       <servlet-mapping>
           <servlet-name>default</servlet-name>
           <url-pattern>/static/*</url-pattern>
       </servlet-mapping>
     

    Then a request to /context/static/images/tomcat.jpg will succeed while a request to /context/images/tomcat2.jpg will fail.

    Author:
    Craig R. McClanahan, Remy Maucherat
    See Also:
    Serialized Form
    • Field Detail

      • sm

        protected static final StringManager sm
        The string manager for this package.
      • BUFFER_SIZE

        protected static final int BUFFER_SIZE
        Size of file transfer buffer in bytes.
        See Also:
        Constant Field Values
      • debug

        protected int debug
        The debugging detail level for this servlet.
      • input

        protected int input
        The input buffer size to use when serving resources.
      • listings

        protected boolean listings
        Should we generate directory listings?
      • readOnly

        protected boolean readOnly
        Read only flag. By default, it's set to true.
      • output

        protected int output
        The output buffer size to use when serving resources.
      • localXsltFile

        protected String localXsltFile
        Allow customized directory listing per directory.
      • contextXsltFile

        protected String contextXsltFile
        Allow customized directory listing per context.
      • globalXsltFile

        protected String globalXsltFile
        Allow customized directory listing per instance.
      • readmeFile

        protected String readmeFile
        Allow a readme file to be included.
      • resources

        protected transient WebResourceRoot resources
        The complete set of web application resources
      • fileEncoding

        protected String fileEncoding
        File encoding to be used when reading static files. If none is specified the platform default is used.
      • sendfileSize

        protected int sendfileSize
        Minimum size for sendfile usage in bytes.
      • useAcceptRanges

        protected boolean useAcceptRanges
        Should the Accept-Ranges: bytes header be send with static resources?
      • showServerInfo

        protected boolean showServerInfo
        Flag to determine if server information is presented.
      • sortListings

        protected boolean sortListings
        Flag to determine if resources should be sorted.
      • sortManager

        protected transient org.apache.catalina.servlets.DefaultServlet.SortManager sortManager
        The sorting manager for sorting files and directories.
    • Constructor Detail

      • DefaultServlet

        public DefaultServlet()
    • Method Detail

      • getRelativePath

        protected String getRelativePath​(HttpServletRequest request)
        Return the relative path associated with this servlet.
        Parameters:
        request - The servlet request we are processing
        Returns:
        the relative path
      • getPathPrefix

        protected String getPathPrefix​(HttpServletRequest request)
        Determines the appropriate path to prepend resources with when generating directory listings. Depending on the behaviour of getRelativePath(HttpServletRequest) this will change.
        Parameters:
        request - the request to determine the path for
        Returns:
        the prefix to apply to all resources in the listing.
      • executePartialPut

        protected File executePartialPut​(HttpServletRequest req,
                                         DefaultServlet.Range range,
                                         String path)
                                  throws IOException
        Handle a partial PUT. New content specified in request is appended to existing content in oldRevisionContent (if present). This code does not support simultaneous partial updates to the same resource.
        Parameters:
        req - The Servlet request
        range - The range that will be written
        path - The path
        Returns:
        the associated file object
        Throws:
        IOException - an IO error occurred
      • checkIfHeaders

        protected boolean checkIfHeaders​(HttpServletRequest request,
                                         HttpServletResponse response,
                                         WebResource resource)
                                  throws IOException
        Check if the conditions specified in the optional If headers are satisfied.
        Parameters:
        request - The servlet request we are processing
        response - The servlet response we are creating
        resource - The resource
        Returns:
        true if the resource meets all the specified conditions, and false if any of the conditions is not satisfied, in which case request processing is stopped
        Throws:
        IOException - an IO error occurred
      • rewriteUrl

        protected String rewriteUrl​(String path)
        URL rewriter.
        Parameters:
        path - Path which has to be rewritten
        Returns:
        the rewritten path
      • serveResource

        protected void serveResource​(HttpServletRequest request,
                                     HttpServletResponse response,
                                     boolean content,
                                     String inputEncoding)
                              throws IOException,
                                     ServletException
        Serve the specified resource, optionally including the data content.
        Parameters:
        request - The servlet request we are processing
        response - The servlet response we are creating
        content - Should the content be included?
        inputEncoding - The encoding to use if it is necessary to access the source as characters rather than as bytes
        Throws:
        IOException - if an input/output error occurs
        ServletException - if a servlet-specified error occurs
      • parseContentRange

        protected DefaultServlet.Range parseContentRange​(HttpServletRequest request,
                                                         HttpServletResponse response)
                                                  throws IOException
        Parse the content-range header.
        Parameters:
        request - The servlet request we are processing
        response - The servlet response we are creating
        Returns:
        the partial content-range, null if the content-range header was invalid or #IGNORE if there is no header to process
        Throws:
        IOException - an IO error occurred
      • renderXml

        @Deprecated
        protected InputStream renderXml​(String contextPath,
                                        WebResource resource,
                                        Source xsltSource)
                                 throws IOException,
                                        ServletException
        Deprecated.
        Unused. Will be removed in Tomcat 9
        Return an InputStream to an XML representation of the contents this directory.
        Parameters:
        contextPath - Context path to which our internal paths are relative
        resource - The associated resource
        xsltSource - The XSL stylesheet
        Returns:
        the XML data
        Throws:
        IOException - an IO error occurred
        ServletException - rendering error
      • renderXml

        @Deprecated
        protected InputStream renderXml​(String contextPath,
                                        WebResource resource,
                                        Source xsltSource,
                                        String encoding)
                                 throws ServletException,
                                        IOException
        Deprecated.
        Unused. Will be removed in Tomcat 10
        Return an InputStream to an XML representation of the contents this directory.
        Parameters:
        contextPath - Context path to which our internal paths are relative
        resource - The associated resource
        xsltSource - The XSL stylesheet
        encoding - The encoding to use to process the readme (if any)
        Returns:
        the XML data
        Throws:
        IOException - an IO error occurred
        ServletException - rendering error
      • renderXml

        protected InputStream renderXml​(HttpServletRequest request,
                                        String contextPath,
                                        WebResource resource,
                                        Source xsltSource,
                                        String encoding)
                                 throws IOException,
                                        ServletException
        Return an InputStream to an XML representation of the contents this directory.
        Parameters:
        request - The HttpServletRequest being served
        contextPath - Context path to which our internal paths are relative
        resource - The associated resource
        xsltSource - The XSL stylesheet
        encoding - The encoding to use to process the readme (if any)
        Returns:
        the XML data
        Throws:
        IOException - an IO error occurred
        ServletException - rendering error
      • renderHtml

        @Deprecated
        protected InputStream renderHtml​(String contextPath,
                                         WebResource resource)
                                  throws IOException
        Deprecated.
        Unused. Will be removed in Tomcat 9
        Return an InputStream to an HTML representation of the contents of this directory.
        Parameters:
        contextPath - Context path to which our internal paths are relative
        resource - The associated resource
        Returns:
        the HTML data
        Throws:
        IOException - an IO error occurred
      • renderHtml

        @Deprecated
        protected InputStream renderHtml​(String contextPath,
                                         WebResource resource,
                                         String encoding)
                                  throws IOException
        Deprecated.
        Unused. Will be removed in Tomcat 10
        Return an InputStream to an HTML representation of the contents of this directory.
        Parameters:
        contextPath - Context path to which our internal paths are relative
        resource - The associated resource
        encoding - The encoding to use to process the readme (if any)
        Returns:
        the HTML data
        Throws:
        IOException - an IO error occurred
      • renderHtml

        protected InputStream renderHtml​(HttpServletRequest request,
                                         String contextPath,
                                         WebResource resource,
                                         String encoding)
                                  throws IOException
        Return an InputStream to an HTML representation of the contents of this directory.
        Parameters:
        request - The HttpServletRequest being served
        contextPath - Context path to which our internal paths are relative
        resource - The associated resource
        encoding - The encoding to use to process the readme (if any)
        Returns:
        the HTML data
        Throws:
        IOException - an IO error occurred
      • renderSize

        protected String renderSize​(long size)
        Render the specified file size (in bytes).
        Parameters:
        size - File size (in bytes)
        Returns:
        the formatted size
      • getReadme

        @Deprecated
        protected String getReadme​(WebResource directory)
        Deprecated.
        Unused. Will be removed in Tomcat 9
        Get the readme file as a string.
        Parameters:
        directory - The directory to search
        Returns:
        the readme for the specified directory
      • getReadme

        protected String getReadme​(WebResource directory,
                                   String encoding)
        Get the readme file as a string.
        Parameters:
        directory - The directory to search
        encoding - The readme encoding
        Returns:
        the readme for the specified directory
      • findXsltSource

        protected Source findXsltSource​(WebResource directory)
                                 throws IOException
        Return a Source for the xsl template (if possible).
        Parameters:
        directory - The directory to search
        Returns:
        the source for the specified directory
        Throws:
        IOException - an IO error occurred
      • checkSendfile

        protected boolean checkSendfile​(HttpServletRequest request,
                                        HttpServletResponse response,
                                        WebResource resource,
                                        long length,
                                        DefaultServlet.Range range)
        Check if sendfile can be used.
        Parameters:
        request - The Servlet request
        response - The Servlet response
        resource - The resource
        length - The length which will be written (will be used only if range is null)
        range - The range that will be written
        Returns:
        true if sendfile should be used (writing is then delegated to the endpoint)
      • checkIfMatch

        protected boolean checkIfMatch​(HttpServletRequest request,
                                       HttpServletResponse response,
                                       WebResource resource)
                                throws IOException
        Check if the if-match condition is satisfied.
        Parameters:
        request - The servlet request we are processing
        response - The servlet response we are creating
        resource - The resource
        Returns:
        true if the resource meets the specified condition, and false if the condition is not satisfied, in which case request processing is stopped
        Throws:
        IOException - an IO error occurred
      • checkIfModifiedSince

        protected boolean checkIfModifiedSince​(HttpServletRequest request,
                                               HttpServletResponse response,
                                               WebResource resource)
        Check if the if-modified-since condition is satisfied.
        Parameters:
        request - The servlet request we are processing
        response - The servlet response we are creating
        resource - The resource
        Returns:
        true if the resource meets the specified condition, and false if the condition is not satisfied, in which case request processing is stopped
      • checkIfNoneMatch

        protected boolean checkIfNoneMatch​(HttpServletRequest request,
                                           HttpServletResponse response,
                                           WebResource resource)
                                    throws IOException
        Check if the if-none-match condition is satisfied.
        Parameters:
        request - The servlet request we are processing
        response - The servlet response we are creating
        resource - The resource
        Returns:
        true if the resource meets the specified condition, and false if the condition is not satisfied, in which case request processing is stopped
        Throws:
        IOException - an IO error occurred
      • checkIfUnmodifiedSince

        protected boolean checkIfUnmodifiedSince​(HttpServletRequest request,
                                                 HttpServletResponse response,
                                                 WebResource resource)
                                          throws IOException
        Check if the if-unmodified-since condition is satisfied.
        Parameters:
        request - The servlet request we are processing
        response - The servlet response we are creating
        resource - The resource
        Returns:
        true if the resource meets the specified condition, and false if the condition is not satisfied, in which case request processing is stopped
        Throws:
        IOException - an IO error occurred
      • generateETag

        protected String generateETag​(WebResource resource)
        Provides the entity tag (the ETag header) for the given resource. Intended to be over-ridden by custom DefaultServlet implementations that wish to use an alternative format for the entity tag.
        Parameters:
        resource - The resource for which an entity tag is required.
        Returns:
        The result of calling WebResource.getETag() on the given resource
      • copy

        @Deprecated
        protected void copy​(WebResource resource,
                            InputStream is,
                            ServletOutputStream ostream)
                     throws IOException
        Deprecated.
        Unused. This will be removed in Tomcat 9. Use copy(InputStream, ServletOutputStream)
        Copy the contents of the specified input stream to the specified output stream, and ensure that both streams are closed before returning (even in the face of an exception).
        Parameters:
        resource - The source resource
        is - The input stream to read the source resource from
        ostream - The output stream to write to
        Throws:
        IOException - if an input/output error occurs
      • copy

        protected void copy​(InputStream is,
                            ServletOutputStream ostream)
                     throws IOException
        Copy the contents of the specified input stream to the specified output stream, and ensure that both streams are closed before returning (even in the face of an exception).
        Parameters:
        is - The input stream to read the source resource from
        ostream - The output stream to write to
        Throws:
        IOException - if an input/output error occurs
      • copy

        @Deprecated
        protected void copy​(WebResource resource,
                            InputStream is,
                            PrintWriter writer,
                            String encoding)
                     throws IOException
        Deprecated.
        Unused. This will be removed in Tomcat 9. Use copy(InputStream, PrintWriter, String)
        Copy the contents of the specified input stream to the specified output stream, and ensure that both streams are closed before returning (even in the face of an exception).
        Parameters:
        resource - The source resource
        is - The input stream to read the source resource from
        writer - The writer to write to
        encoding - The encoding to use when reading the source input stream
        Throws:
        IOException - if an input/output error occurs
      • copy

        protected void copy​(InputStream is,
                            PrintWriter writer,
                            String encoding)
                     throws IOException
        Copy the contents of the specified input stream to the specified output stream, and ensure that both streams are closed before returning (even in the face of an exception).
        Parameters:
        is - The input stream to read the source resource from
        writer - The writer to write to
        encoding - The encoding to use when reading the source input stream
        Throws:
        IOException - if an input/output error occurs
      • copy

        protected void copy​(WebResource resource,
                            ServletOutputStream ostream,
                            DefaultServlet.Range range)
                     throws IOException
        Copy the contents of the specified input stream to the specified output stream, and ensure that both streams are closed before returning (even in the face of an exception).
        Parameters:
        resource - The source resource
        ostream - The output stream to write to
        range - Range the client wanted to retrieve
        Throws:
        IOException - if an input/output error occurs
      • copy

        protected void copy​(WebResource resource,
                            ServletOutputStream ostream,
                            Iterator<DefaultServlet.Range> ranges,
                            String contentType)
                     throws IOException
        Copy the contents of the specified input stream to the specified output stream, and ensure that both streams are closed before returning (even in the face of an exception).
        Parameters:
        resource - The source resource
        ostream - The output stream to write to
        ranges - Enumeration of the ranges the client wanted to retrieve
        contentType - Content type of the resource
        Throws:
        IOException - if an input/output error occurs
      • copyRange

        protected IOException copyRange​(InputStream istream,
                                        ServletOutputStream ostream)
        Copy the contents of the specified input stream to the specified output stream, and ensure that both streams are closed before returning (even in the face of an exception).
        Parameters:
        istream - The input stream to read from
        ostream - The output stream to write to
        Returns:
        Exception which occurred during processing
      • copyRange

        protected IOException copyRange​(Reader reader,
                                        PrintWriter writer)
        Copy the contents of the specified input stream to the specified output stream, and ensure that both streams are closed before returning (even in the face of an exception).
        Parameters:
        reader - The reader to read from
        writer - The writer to write to
        Returns:
        Exception which occurred during processing
      • copyRange

        protected IOException copyRange​(InputStream istream,
                                        ServletOutputStream ostream,
                                        long start,
                                        long end)
        Copy the contents of the specified input stream to the specified output stream, and ensure that both streams are closed before returning (even in the face of an exception).
        Parameters:
        istream - The input stream to read from
        ostream - The output stream to write to
        start - Start of the range which will be copied
        end - End of the range which will be copied
        Returns:
        Exception which occurred during processing