org.mortbay.jetty.servlet
Class DefaultServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.mortbay.jetty.servlet.DefaultServlet

All Implemented Interfaces:

ResourceFactory, Serializable, Servlet, ServletConfig

public class DefaultServlet

extends HttpServlet

implements ResourceFactory

The default servlet. This servlet, normally mapped to /, provides the handling for static content, OPTION and TRACE methods for the context. The following initParameters are supported:

                                                                      
   acceptRanges     If true, range requests and responses are         
                    supported                                         
                                                                      
   dirAllowed       If true, directory listings are returned if no    
                    welcome file is found. Else 403 Forbidden.        

   redirectWelcome  If true, welcome files are redirected rather than
                    forwarded to.

   gzip             If set to true, then static content will be served as 
                    gzip content encoded if a matching resource is 
                    found ending with ".gz"

  resourceBase      Set to replace the context resource base

  relativeResourceBase    
                    Set with a pathname relative to the base of the
                    servlet context root. Useful for only serving static content out
                    of only specific subdirectories.
 
  aliases           If True, aliases of resources are allowed (eg. symbolic
                    links and caps variations). May bypass security constraints.
                    
  maxCacheSize      The maximum total size of the cache or 0 for no cache.
  maxCachedFileSize The maximum size of a file to cache
  maxCachedFiles    The maximum number of files to cache
  
  useFileMappedBuffer 
                    If set to true, it will use mapped file buffer to serve static content
                    when using NIO connector. Setting this value to false means that
                    a direct buffer will be used instead of a mapped file buffer. 
                    By default, this is set to true.
 

The MOVE method is allowed if PUT and DELETE are allowed

Author:

Greg Wilkins (gregw), Nigel Canonizado

See Also:

Serialized Form

Constructor Summary

DefaultServlet()

Method Summary

void	destroy() Called by the servlet container to indicate to a servlet that the servlet is being taken out of service.
protected void	doGet(HttpServletRequest request, HttpServletResponse response) Called by the server (via the service method) to allow a servlet to handle a GET request.
protected void	doPost(HttpServletRequest request, HttpServletResponse response) Called by the server (via the service method) to allow a servlet to handle a POST request.
Resource	getResource(String pathInContext) get Resource to serve.
void	init() A convenience method which can be overridden so that there's no need to call super.init(config).
protected boolean	passConditionalHeaders(HttpServletRequest request, HttpServletResponse response, Resource resource, HttpContent content)
protected void	sendData(HttpServletRequest request, HttpServletResponse response, boolean include, Resource resource, HttpContent content, Enumeration reqRanges)
protected void	sendDirectory(HttpServletRequest request, HttpServletResponse response, Resource resource, boolean parent)
protected void	writeHeaders(HttpServletResponse response, HttpContent content, long count)

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPut, 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

Constructor Detail

DefaultServlet

public DefaultServlet()

Method Detail

init

public void init()
          throws UnavailableException

Description copied from class: GenericServlet

A convenience method which can be overridden so that there's no need to call super.init(config).

Instead of overriding GenericServlet.init(ServletConfig), simply override this method and it will be called by GenericServlet.init(ServletConfig config). The ServletConfig object can still be retrieved via GenericServlet.getServletConfig().

Overrides:

init in class GenericServlet

Throws:

UnavailableException

getResource

public Resource getResource(String pathInContext)

get Resource to serve. Map a path to a resource. The default implementation calls HttpContext.getResource but derived servlets may provide their own mapping.

Specified by:

getResource in interface ResourceFactory

Parameters:

pathInContext - The path to find a resource for.

Returns:

The resource to serve.

doGet

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

Description copied from class: HttpServlet

Called by the server (via the service method) to allow a servlet to handle a GET request.

Overriding this method to support a GET request also automatically supports an HTTP HEAD request. A HEAD request is a GET request that returns no body in the response, only the request header fields.

When overriding this method, read the request data, write the response headers, get the response's writer or output stream object, and finally, write the response data. It's best to include content type and encoding. When using a PrintWriter object to return the response, set the content type before accessing the PrintWriter object.

The servlet container must write the headers before committing the response, because in HTTP the headers must be sent before the response body.

Where possible, set the Content-Length header (with the ServletResponse.setContentLength(int) method), to allow the servlet container to use a persistent connection to return its response to the client, improving performance. The content length is automatically set if the entire response fits inside the response buffer.

When using HTTP 1.1 chunked encoding (which means that the response has a Transfer-Encoding header), do not set the Content-Length header.

The GET method should be safe, that is, without any side effects for which users are held responsible. For example, most form queries have no side effects. If a client request is intended to change stored data, the request should use some other HTTP method.

The GET method should also be idempotent, meaning that it can be safely repeated. Sometimes making a method safe also makes it idempotent. For example, repeating queries is both safe and idempotent, but buying a product online or modifying data is neither safe nor idempotent.

If the request is incorrectly formatted, doGet returns an HTTP "Bad Request" message.

Overrides:

doGet in class HttpServlet

Parameters:

request - an HttpServletRequest object that contains the request the client has made of the servlet

response - an HttpServletResponse object that contains the response the servlet sends to the client

Throws:

IOException - if an input or output error is detected when the servlet handles the GET request

ServletException - if the request for the GET could not be handled

See Also:

ServletResponse.setContentType(java.lang.String)

doPost

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

Description copied from class: HttpServlet

Called by the server (via the service method) to allow a servlet to handle a POST request. The HTTP POST method allows the client to send data of unlimited length to the Web server a single time and is useful when posting information such as credit card numbers.

When overriding this method, read the request data, write the response headers, get the response's writer or output stream object, and finally, write the response data. It's best to include content type and encoding. When using a PrintWriter object to return the response, set the content type before accessing the PrintWriter object.

The servlet container must write the headers before committing the response, because in HTTP the headers must be sent before the response body.

Where possible, set the Content-Length header (with the ServletResponse.setContentLength(int) method), to allow the servlet container to use a persistent connection to return its response to the client, improving performance. The content length is automatically set if the entire response fits inside the response buffer.

When using HTTP 1.1 chunked encoding (which means that the response has a Transfer-Encoding header), do not set the Content-Length header.

This method does not need to be either safe or idempotent. Operations requested through POST can have side effects for which the user can be held accountable, for example, updating stored data or buying items online.

If the HTTP POST request is incorrectly formatted, doPost returns an HTTP "Bad Request" message.

Overrides:

doPost in class HttpServlet

Parameters:

request - an HttpServletRequest object that contains the request the client has made of the servlet

response - an HttpServletResponse object that contains the response the servlet sends to the client

Throws:

IOException - if an input or output error is detected when the servlet handles the request

ServletException - if the request for the POST could not be handled

See Also:

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

passConditionalHeaders

protected boolean passConditionalHeaders(HttpServletRequest request,
                                         HttpServletResponse response,
                                         Resource resource,
                                         HttpContent content)
                                  throws IOException

Throws:

IOException

sendDirectory

protected void sendDirectory(HttpServletRequest request,
                             HttpServletResponse response,
                             Resource resource,
                             boolean parent)
                      throws IOException

Throws:

IOException

sendData

protected void sendData(HttpServletRequest request,
                        HttpServletResponse response,
                        boolean include,
                        Resource resource,
                        HttpContent content,
                        Enumeration reqRanges)
                 throws IOException

Throws:

IOException

writeHeaders

protected void writeHeaders(HttpServletResponse response,
                            HttpContent content,
                            long count)
                     throws IOException

Throws:

IOException

destroy

public void destroy()

Description copied from class: GenericServlet

Called by the servlet container to indicate to a servlet that the servlet is being taken out of service. See Servlet.destroy().

Specified by:

destroy in interface Servlet

Overrides:

destroy in class GenericServlet