All Implemented Interfaces:

java.io.Serializable, Servlet, ServletConfig

Direct Known Subclasses:

HttpServlet

public abstract class GenericServlet
extends java.lang.Object
implements Servlet, ServletConfig, java.io.Serializable

Since:

1.0

See Also:

Serialized Form

• Constructor Summary

  Constructors

  Constructor and Description
  GenericServlet () Does nothing.

• Method Summary

  Methods

  Modifier and Type	Method and Description
  void	destroy () Called by the server when it no longer needs the servlet.
  java.lang.String	getInitParameter (java.lang.String name) Gets a servlet's initialization parameter
  java.util.Enumeration	getInitParameterNames () Gets all the initialization parameters
  ServletConfig	getServletConfig () Gets the servlet config class
  ServletContext	getServletContext () Returns the servlets context
  java.lang.String	getServletInfo () The servlet programmer can put other additional info (version number, etc) here.
  java.lang.String	getServletName () Gets you the name of this servlet's instance.
  void	init () Automatically called by init(ServletConfig config).
  void	init (ServletConfig config) Initializes the servlet.
  void	log (java.lang.String message) Writes the class name and a message to the log.
  void	log (java.lang.String message, java.lang.Throwable throwable) Writes the class name, a message and a stack trace to the log.
  abstract void	service (ServletRequest request, ServletResponse response) Called by the server every time it wants the servlet to handle a request.

  • Methods inherited from class java.lang.Object

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

• Constructor Detail

  • GenericServlet

    public GenericServlet()

    Does nothing.

• Method Detail

  • destroy

    public void destroy()

    Called by the server when it no longer needs the servlet. The servlet programmer should use this method to free all the resources the servlet is holding.

    This version does nothing because it has nothing to clean up.

    Note that the the 2.1 Spec says that this should do nothing, but the 2.1 API Doc says that it logs the destroy action.

    Specified by:

    destroy in interface Servlet

  • getInitParameter

    public java.lang.String getInitParameter(java.lang.String name)

    Gets a servlet's initialization parameter

    Specified by:

    getInitParameter in interface ServletConfig

    Parameters:

    name - the name of the wanted parameter

    Returns:

    the value of the wanted parameter. null if the named parameter is not present.

  • getInitParameterNames

    public java.util.Enumeration getInitParameterNames()

    Gets all the initialization parameters

    Specified by:

    getInitParameterNames in interface ServletConfig

    Returns:

    an Enumeration of all the parameters

  • getServletConfig

    public ServletConfig getServletConfig()

    Gets the servlet config class

    Specified by:

    getServletConfig in interface Servlet

    Returns:

    The config class

  • getServletContext

    public ServletContext getServletContext()

    Returns the servlets context

    Specified by:

    getServletContext in interface ServletConfig

    Returns:

    The context

  • getServletInfo

    public java.lang.String getServletInfo()

    The servlet programmer can put other additional info (version number, etc) here.

    Specified by:

    getServletInfo in interface Servlet

    Returns:

    The String holding the information

  • init

    public void init(ServletConfig config)
     throws ServletException 

    Initializes the servlet. Called by the server exactly once during the lifetime of the servlet. This method can be used to setup resources (connections to a database for example) for this servlet.

    This version saves the ServletConfig and calls init(). This means that a servlet can just override init(). Note that if a servlet overrides this method it should call super.init(config) otherwise the other methods in GenericServlet are not garanteed to work.

    Specified by:

    init in interface Servlet

    Parameters:

    config - This servlet configuration class

    Throws:

    ServletException - If an error occurs

    See Also:

    UnavailableException

  • init

    public void init()
     throws ServletException 

    Automatically called by init(ServletConfig config). This version does nothing.

    Throws:

    ServletException - If an error occurs

    Since:

    2.1

  • log

    public void log(java.lang.String message)

    Writes the class name and a message to the log. Calls getServletContext().log().

    Parameters:

    message - the message to write

  • log

    public void log(java.lang.String message,
     java.lang.Throwable throwable)

    Writes the class name, a message and a stack trace to the log. Calls getServletContext().log().

    Parameters:

    message - the message to write

    throwable - the object that was thrown to cause this log

    Since:

    2.1

  • service

    public abstract void service(ServletRequest request,
     ServletResponse response)
     throws ServletException,
     java.io.IOException

    Called by the server every time it wants the servlet to handle a request.

    Specified by:

    service in interface Servlet

    Parameters:

    request - all the request information

    response - class to write all the response data to

    Throws:

    ServletException - If an error occurs

    java.io.IOException - If an error occurs

    See Also:

    SingleThreadModel

  • getServletName

    public java.lang.String getServletName()

    Gets you the name of this servlet's instance. Calls its config's getServletName.

    Specified by:

    getServletName in interface ServletConfig