org.apache.felix.webconsole.plugins.upnp.internal
Class ControlServlet

java.lang.Object
  extended by javax.servlet.GenericServlet
      extended by javax.servlet.http.HttpServlet
          extended by org.apache.felix.webconsole.plugins.upnp.internal.ControlServlet
All Implemented Interfaces:
Serializable, Servlet, ServletConfig, ServiceTrackerCustomizer

public class ControlServlet
extends HttpServlet
implements ServiceTrackerCustomizer

This class handles requests from the Web Interface. It is separated from the WebConsolePlugin just to improve readability. This servlet actually is not registered in HTTP service.

See Also:
Serialized Form

Method Summary
 Object addingService(ServiceReference ref)
          A service is being added to the ServiceTracker.
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.
 void modifiedService(ServiceReference ref, Object serv)
          A service tracked by the ServiceTracker has been modified.
 void removedService(ServiceReference ref, Object serv)
          A service tracked by the ServiceTracker has been removed.
 
Methods inherited from class javax.servlet.http.HttpServlet
doDelete, doHead, doOptions, doPut, doTrace, getLastModified, service, service
 
Methods inherited from class javax.servlet.GenericServlet
destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, init, init, log, log
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

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.

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:
ServletException - if the request for the GET could not be handled
IOException - if an input or output error is detected when the servlet handles the GET request
See Also:
HttpServlet.doGet(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)

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:
ServletException - if the request for the POST could not be handled
IOException - if an input or output error is detected when the servlet handles the request
See Also:
HttpServlet.doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)

modifiedService

public final void modifiedService(ServiceReference ref,
                                  Object serv)
Description copied from interface: ServiceTrackerCustomizer
A service tracked by the ServiceTracker has been modified.

This method is called when a service being tracked by the ServiceTracker has had it properties modified.

Specified by:
modifiedService in interface ServiceTrackerCustomizer
Parameters:
ref - The reference to the service that has been modified.
serv - The service object for the specified referenced service.
See Also:
ServiceTrackerCustomizer.modifiedService(org.osgi.framework.ServiceReference, java.lang.Object)

removedService

public final void removedService(ServiceReference ref,
                                 Object serv)
Description copied from interface: ServiceTrackerCustomizer
A service tracked by the ServiceTracker has been removed.

This method is called after a service is no longer being tracked by the ServiceTracker.

Specified by:
removedService in interface ServiceTrackerCustomizer
Parameters:
ref - The reference to the service that has been removed.
serv - The service object for the specified referenced service.
See Also:
ServiceTrackerCustomizer.removedService(org.osgi.framework.ServiceReference, java.lang.Object)

addingService

public final Object addingService(ServiceReference ref)
Description copied from interface: ServiceTrackerCustomizer
A service is being added to the ServiceTracker.

This method is called before a service which matched the search parameters of the ServiceTracker is added to the ServiceTracker. This method should return the service object to be tracked for the specified ServiceReference. The returned service object is stored in the ServiceTracker and is available from the getService and getServices methods.

Specified by:
addingService in interface ServiceTrackerCustomizer
Parameters:
ref - The reference to the service being added to the ServiceTracker.
Returns:
The service object to be tracked for the specified referenced service or null if the specified referenced service should not be tracked.
See Also:
ServiceTrackerCustomizer.addingService(org.osgi.framework.ServiceReference)


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