org.apache.catalina.servlets

Class DefaultServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

org.apache.catalina.servlets.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

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	DefaultServlet.CompressionFormat
protected static class	DefaultServlet.Range

Field Summary

Fields

Modifier and Type	Field and Description
protected static int	BUFFER_SIZE Size of file transfer buffer in bytes.
protected DefaultServlet.CompressionFormat[]	compressionFormats List of compression formats to serve and their preference order.
protected String	contextXsltFile Allow customized directory listing per context.
protected int	debug The debugging detail level for this servlet.
protected String	fileEncoding File encoding to be used when reading static files.
protected static ArrayList<DefaultServlet.Range>	FULL Full range marker.
protected String	globalXsltFile Allow customized directory listing per instance.
protected int	input The input buffer size to use when serving resources.
protected boolean	listings Should we generate directory listings?
protected String	localXsltFile Allow customized directory listing per directory.
protected static String	mimeSeparation MIME multipart separation string
protected int	output The output buffer size to use when serving resources.
protected String	readmeFile Allow a readme file to be included.
protected boolean	readOnly Read only flag.
protected WebResourceRoot	resources The complete set of web application resources
protected int	sendfileSize Minimum size for sendfile usage in bytes.
protected boolean	showServerInfo Flag to determine if server information is presented.
protected static StringManager	sm The string manager for this package.
protected boolean	useAcceptRanges Should the Accept-Ranges: bytes header be send with static resources?

Constructor Summary

Constructors

Constructor and Description
DefaultServlet()

Method Summary

Modifier and Type	Method and Description
protected boolean	checkIfHeaders(HttpServletRequest request, HttpServletResponse response, WebResource resource) Check if the conditions specified in the optional If headers are satisfied.
protected boolean	checkIfMatch(HttpServletRequest request, HttpServletResponse response, WebResource resource) Check if the if-match condition is satisfied.
protected boolean	checkIfModifiedSince(HttpServletRequest request, HttpServletResponse response, WebResource resource) Check if the if-modified-since condition is satisfied.
protected boolean	checkIfNoneMatch(HttpServletRequest request, HttpServletResponse response, WebResource resource) Check if the if-none-match condition is satisfied.
protected boolean	checkIfUnmodifiedSince(HttpServletRequest request, HttpServletResponse response, WebResource resource) Check if the if-unmodified-since condition is satisfied.
protected boolean	checkSendfile(HttpServletRequest request, HttpServletResponse response, WebResource resource, long length, DefaultServlet.Range range) Check if sendfile can be used.
protected void	copy(WebResource resource, InputStream is, PrintWriter writer, String encoding) 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).
protected void	copy(WebResource resource, InputStream is, 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).
protected void	copy(WebResource resource, ServletOutputStream ostream, DefaultServlet.Range range) 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).
protected void	copy(WebResource resource, ServletOutputStream ostream, Iterator<DefaultServlet.Range> ranges, String contentType) 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).
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).
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).
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).
void	destroy() Finalize this servlet.
protected void	doDelete(HttpServletRequest req, HttpServletResponse resp) Process a DELETE request for the specified resource.
protected void	doGet(HttpServletRequest request, HttpServletResponse response) Process a GET request for the specified resource.
protected void	doHead(HttpServletRequest request, HttpServletResponse response) Process a HEAD request for the specified resource.
protected void	doOptions(HttpServletRequest req, HttpServletResponse resp) Override default implementation to ensure that TRACE is correctly handled.
protected void	doPost(HttpServletRequest request, HttpServletResponse response) Process a POST request for the specified resource.
protected void	doPut(HttpServletRequest req, HttpServletResponse resp) Process a PUT request for the specified resource.
protected File	executePartialPut(HttpServletRequest req, DefaultServlet.Range range, String path) Handle a partial PUT.
protected Source	findXsltSource(WebResource directory) Return a Source for the xsl template (if possible).
protected String	getPathPrefix(HttpServletRequest request) Determines the appropriate path to prepend resources with when generating directory listings.
protected String	getReadme(WebResource directory, String encoding) Get the readme file as a string.
protected String	getRelativePath(HttpServletRequest request) Return the relative path associated with this servlet.
protected String	getRelativePath(HttpServletRequest request, boolean allowEmptyPath)
void	init() Initialize this servlet.
protected DefaultServlet.Range	parseContentRange(HttpServletRequest request, HttpServletResponse response) Parse the content-range header.
protected ArrayList<DefaultServlet.Range>	parseRange(HttpServletRequest request, HttpServletResponse response, WebResource resource) Parse the range header.
protected InputStream	render(String contextPath, WebResource resource, String encoding) Decide which way to render.
protected InputStream	renderHtml(String contextPath, WebResource resource, String encoding) Return an InputStream to an HTML representation of the contents of this directory.
protected String	renderSize(long size) Render the specified file size (in bytes).
protected InputStream	renderXml(String contextPath, WebResource resource, Source xsltSource, String encoding) Return an InputStream to an XML representation of the contents this directory.
protected String	rewriteUrl(String path) URL rewriter.
protected void	serveResource(HttpServletRequest request, HttpServletResponse response, boolean content, String encoding) Serve the specified resource, optionally including the data content.

Methods inherited from class javax.servlet.http.HttpServlet

doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

sm

protected static final StringManager sm

The string manager for this package.

FULL

protected static final ArrayList<DefaultServlet.Range> FULL

Full range marker.

mimeSeparation

protected static final String mimeSeparation

MIME multipart separation string

See Also:

Constant Field Values

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.

compressionFormats

protected DefaultServlet.CompressionFormat[] compressionFormats

List of compression formats to serve and their preference order.

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.

Constructor Detail

DefaultServlet

public DefaultServlet()

Method Detail

destroy

public void destroy()

Finalize this servlet.

Specified by:

destroy in interface Servlet

Overrides:

destroy in class GenericServlet

init

public void init()
          throws ServletException

Initialize this servlet.

Overrides:

init in class GenericServlet

Throws:

ServletException - if an exception occurs that interrupts the servlet's normal operation

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

getRelativePath

protected String getRelativePath(HttpServletRequest request,
                                 boolean allowEmptyPath)

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.

doGet

protected void doGet(HttpServletRequest request,
                     HttpServletResponse response)
              throws IOException,
                     ServletException

Process a GET request for the specified resource.

Overrides:

doGet in class HttpServlet

Parameters:

request - The servlet request we are processing

response - The servlet response we are creating

Throws:

IOException - if an input/output error occurs

ServletException - if a servlet-specified error occurs

See Also:

ServletResponse.setContentType(java.lang.String)

doHead

protected void doHead(HttpServletRequest request,
                      HttpServletResponse response)
               throws IOException,
                      ServletException

Process a HEAD request for the specified resource.

Overrides:

doHead in class HttpServlet

Parameters:

request - The servlet request we are processing

response - The servlet response we are creating

Throws:

IOException - if an input/output error occurs

ServletException - if a servlet-specified error occurs

doOptions

protected void doOptions(HttpServletRequest req,
                         HttpServletResponse resp)
                  throws ServletException,
                         IOException

Override default implementation to ensure that TRACE is correctly handled.

Overrides:

doOptions in class HttpServlet

Parameters:

req - the HttpServletRequest object that contains the request the client made of the servlet

resp - the HttpServletResponse object that contains the response the servlet returns to the client

Throws:

IOException - if an input or output error occurs while the servlet is handling the OPTIONS request

ServletException - if the request for the OPTIONS cannot be handled

doPost

protected void doPost(HttpServletRequest request,
                      HttpServletResponse response)
               throws IOException,
                      ServletException

Process a POST request for the specified resource.

Overrides:

doPost in class HttpServlet

Parameters:

request - The servlet request we are processing

response - The servlet response we are creating

Throws:

IOException - if an input/output error occurs

ServletException - if a servlet-specified error occurs

See Also:

ServletOutputStream, ServletResponse.setContentType(java.lang.String)

doPut

protected void doPut(HttpServletRequest req,
                     HttpServletResponse resp)
              throws ServletException,
                     IOException

Process a PUT request for the specified resource.

Overrides:

doPut in class HttpServlet

Parameters:

req - The servlet request we are processing

resp - The servlet response we are creating

Throws:

IOException - if an input/output error occurs

ServletException - if a servlet-specified error occurs

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

doDelete

protected void doDelete(HttpServletRequest req,
                        HttpServletResponse resp)
                 throws ServletException,
                        IOException

Process a DELETE request for the specified resource.

Overrides:

doDelete in class HttpServlet

Parameters:

req - The servlet request we are processing

resp - The servlet response we are creating

Throws:

IOException - if an input/output error occurs

ServletException - if a servlet-specified error occurs

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 encoding)
                      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?

encoding - 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 a)re processing

response - The servlet response we are creating

Returns:

the range object

Throws:

IOException - an IO error occurred

parseRange

protected ArrayList<DefaultServlet.Range> parseRange(HttpServletRequest request,
                                                     HttpServletResponse response,
                                                     WebResource resource)
                                              throws IOException

Parse the range header.

Parameters:

request - The servlet request we are processing

response - The servlet response we are creating

resource - The resource

Returns:

a list of ranges

Throws:

IOException - an IO error occurred

render

protected InputStream render(String contextPath,
                             WebResource resource,
                             String encoding)
                      throws IOException,
                             ServletException

Decide which way to render. HTML or XML.

Parameters:

contextPath - The path

resource - The resource

encoding - The encoding to use to process the readme (if any)

Returns:

the input stream with the rendered output

Throws:

IOException - an IO error occurred

ServletException - rendering error

renderXml

protected InputStream renderXml(String contextPath,
                                WebResource resource,
                                Source xsltSource,
                                String encoding)
                         throws IOException,
                                ServletException

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

renderHtml

protected InputStream renderHtml(String contextPath,
                                 WebResource resource,
                                 String encoding)
                          throws IOException

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

renderSize

protected String renderSize(long size)

Render the specified file size (in bytes).

Parameters:

size - File size (in bytes)

Returns:

the formatted size

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

copy

protected void copy(WebResource resource,
                    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:

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(WebResource resource,
                    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:

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(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