com.mortbay.Servlets
Class SessionDump

java.lang.Object
  |
  +--javax.servlet.GenericServlet
        |
        +--javax.servlet.http.HttpServlet
              |
              +--com.mortbay.Servlets.SessionDump

public class SessionDump
extends javax.servlet.http.HttpServlet

This is an example of a simple Servlet

See Also:
Serialized Form

Constructor Summary
SessionDump()
           
 
Method Summary
 void doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
          Receives an HTTP GET request from the protected service method and handles the request.
 void doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
          Receives an HTTP POST request from the protected service method and handles the request.
 java.lang.String getServletInfo()
          Returns a String that contains information about the servlet such as its author, version, and copyright information.
 void init(javax.servlet.ServletConfig config)
          Initializes this servlet.
 
Methods inherited from class javax.servlet.http.HttpServlet
doDelete, doOptions, doPut, doTrace, getLastModified, service, service
 
Methods inherited from class javax.servlet.GenericServlet
destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, init, log, log
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SessionDump

public SessionDump()
Method Detail

init

public void init(javax.servlet.ServletConfig config)
          throws javax.servlet.ServletException
Description copied from class: javax.servlet.GenericServlet
Initializes this servlet.

The servlet engine calls this method once, automatically, each time it loads the servlet. This method is guaranteed to finish before the servlet accepts any requests to its service method. If a fatal error occurs while the servlet is being initialized, the servlet engine should throw an UnavailableException, rather than calling the System.exit method.

The init method stores the ServletConfig object it receives from the servlet engine. If you override init, you should either call super.init or store the ServletConfig object in the new init method. If you decide to store the ServletConfig object in a different location, you should also override the GenericServlet.getServletConfig() method.

Overrides:
init in class javax.servlet.GenericServlet
Tags copied from class: javax.servlet.GenericServlet
Parameters:
config - the ServletConfig object that contains initialization parameters for this servlet
Throws:
javax.servlet.ServletException - if an exception occurs that interrupts the servlet's normal operation
See Also:
UnavailableException

doPost

public void doPost(javax.servlet.http.HttpServletRequest request,
                   javax.servlet.http.HttpServletResponse response)
            throws javax.servlet.ServletException,
                   java.io.IOException
Description copied from class: javax.servlet.http.HttpServlet
Receives an HTTP POST request from the protected service method and handles the request. The HTTP POST method allows the client to send data of unlimited length to the Web server once and is useful when posting information such as credit card numbers.

If you override this method, you should read data from the HttpServletRequest object, set headers for the response (including Content-Type and Content-Encoding), access a PrintWriter or output stream object, and then write any response data using a ServletOutputStream object.

If you use a PrintWriter object to write response data, set the Content-Type header before you access the PrintWriter object. The servlet engine must write the headers before the the response data, because the headers can be flushed at any time after the servlet engine begins to write the body of the response.

If you use HTTP 1.1 chunked encoding (which means that the response has a Transfer-Encoding header), do not set the Content-Length header. If you do not use chunked encoding, set the content length to allow the servlet to take advantage of the HTTP "connection keep alive" feature, If you cannot set the content length and therefore cannot use "keep alive," you may be able to avoid the performance penalty if the response fits in an internal buffer.

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 javax.servlet.http.HttpServlet
Tags copied from class: javax.servlet.http.HttpServlet
Parameters:
req - an HttpServletRequest object that contains the request the client has made of the servlet
resp - an HttpServletResponse object that contains the response the servlet sends to the object
Throws:
java.io.IOException - if an input or output error is detected when the servlet handles the request
javax.servlet.ServletException - if the request for the POST could not be handled
See Also:
ServletOutputStream, ServletResponse.setContentType(java.lang.String)

doGet

public void doGet(javax.servlet.http.HttpServletRequest request,
                  javax.servlet.http.HttpServletResponse response)
           throws javax.servlet.ServletException,
                  java.io.IOException
Description copied from class: javax.servlet.http.HttpServlet
Receives an HTTP GET request from the protected service method and handles the request. The GET method allows a client to read information from the Web server, passing a query string appended to an URL to tell the server what information to return.

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.

If you override this method, you should read data from the request, set entity headers in the response, access the writer or output stream object, and finally, write the response data. When you set headers, be sure to include content type and encoding. If you use a PrintWriter object to return the response, you must set the content type before you access the PrintWriter object.

The servlet engine must write the headers before the response data, because the headers can be flushed at any time after the data is written.

If you can set the Content-Length header (with the javax.servlet.ServletResponse.#contentType method), the servlet can use a persistent connection to return its response to the client, improving performance dramatically. If you cannot set Content-Length, you can sometimes avoid the performance penalty if the response fits in an internal 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 javax.servlet.http.HttpServlet
Tags copied from class: javax.servlet.http.HttpServlet
Parameters:
req - an HttpServletRequest object that contains the request the client has made of the servlet
resp - an HttpServletResponse object that contains the response the servlet sends to the object
Throws:
java.io.IOException - if an input or output error is detected when the servlet handles the GET request
javax.servlet.ServletException - if the request for the GET could not be handled
See Also:
ServletResponse.setContentType(java.lang.String)

getServletInfo

public java.lang.String getServletInfo()
Description copied from class: javax.servlet.GenericServlet
Returns a String that contains information about the servlet such as its author, version, and copyright information. You must override this method before it returns this information. If you do not override this method, it returns an empty string.
Overrides:
getServletInfo in class javax.servlet.GenericServlet
Tags copied from class: javax.servlet.GenericServlet
Returns:
String a empty String until you override this method