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| java.lang.Object
 javax.servlet.GenericServlet
All known Subclasses: javax.servlet.http.HttpServlet,
| GenericServlet | | abstract public class GenericServlet implements Servlet,ServletConfig,java.io.Serializable(Code) | | Defines a generic, protocol-independent
servlet. To write an HTTP servlet for use on the
Web, extend
javax.servlet.http.HttpServlet instead.
GenericServlet implements the Servlet
and ServletConfig interfaces. GenericServlet
may be directly extended by a servlet, although it's more common to extend
a protocol-specific subclass such as HttpServlet.
GenericServlet makes writing servlets
easier. It provides simple versions of the lifecycle methods
init and destroy and of the methods
in the ServletConfig interface. GenericServlet
also implements the log method, declared in the
ServletContext interface.
To write a generic servlet, you need only
override the abstract service method.
author:
Various
version:
$Version$ |
| Method Summary | |
| public void | destroy()
Called by the servlet container to indicate to a servlet that the
servlet is being taken out of service. | | public String | getInitParameter(String name)
Returns a String containing the value of the named
initialization parameter, or null if the parameter does
not exist. | | public Enumeration | getInitParameterNames()
Returns the names of the servlet's initialization parameters
as an Enumeration of String objects,
or an empty Enumeration if the servlet has no
initialization parameters. | | public ServletConfig | getServletConfig()
Returns this servlet's
ServletConfig object. | | public ServletContext | getServletContext()
Returns a reference to the
ServletContext in which this servlet
is running. | | public String | getServletInfo()
Returns information about the servlet, such as
author, version, and copyright. | | public String | getServletName()
Returns the name of this servlet instance. | | public void | init(ServletConfig config)
Called by the servlet container to indicate to a servlet that the
servlet is being placed into service. | | public void | init()
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 . | | public void | log(String msg)
Writes the specified message to a servlet log file, prepended by the
servlet's name. | | public void | log(String message, Throwable t)
Writes an explanatory message and a stack trace
for a given Throwable exception
to the servlet log file, prepended by the servlet's name. | | abstract public void | service(ServletRequest req, ServletResponse res)
Called by the servlet container to allow the servlet to respond to
a request. |
| GenericServlet | | public GenericServlet()(Code) | | Does nothing. All of the servlet initialization
is done by one of the init methods.
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| destroy | | public void destroy()(Code) | | Called by the servlet container to indicate to a servlet that the
servlet is being taken out of service. See
Servlet.destroy .
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| getInitParameter | | public String getInitParameter(String name)(Code) | | Returns a String containing the value of the named
initialization parameter, or null if the parameter does
not exist. See
ServletConfig.getInitParameter .
This method is supplied for convenience. It gets the
value of the named parameter from the servlet's
ServletConfig object.
Parameters:
name - a String specifying the name of the initialization parameter String a String containing the valueof the initialization parameter |
| getInitParameterNames | | public Enumeration getInitParameterNames()(Code) | | Returns the names of the servlet's initialization parameters
as an Enumeration of String objects,
or an empty Enumeration if the servlet has no
initialization parameters. See
ServletConfig.getInitParameterNames .
This method is supplied for convenience. It gets the
parameter names from the servlet's ServletConfig object.
Enumeration an enumeration of Stringobjects containing the names of the servlet's initialization parameters |
| getServletConfig | | public ServletConfig getServletConfig()(Code) | | Returns this servlet's
ServletConfig object.
ServletConfig the ServletConfig objectthat initialized this servlet |
| getServletContext | | public ServletContext getServletContext()(Code) | | Returns a reference to the
ServletContext in which this servlet
is running. See
ServletConfig.getServletContext .
This method is supplied for convenience. It gets the
context from the servlet's ServletConfig object.
ServletContext the ServletContext objectpassed to this servlet by the initmethod |
| getServletInfo | | public String getServletInfo()(Code) | | Returns information about the servlet, such as
author, version, and copyright.
By default, this method returns an empty string. Override this method
to have it return a meaningful value. See
Servlet.getServletInfo .
String information about this servlet, by default anempty string |
| init | | public void init(ServletConfig config) throws ServletException(Code) | | Called by the servlet container to indicate to a servlet that the
servlet is being placed into service. See
Servlet.init .
This implementation stores the
ServletConfig object it receives from the servlet container for later use.
When overriding this form of the method, call
super.init(config).
Parameters:
config - the ServletConfig objectthat contains configutationinformation for this servlet
exception:
ServletException - if an exception occurs thatinterrupts the servlet's normaloperation
See Also: UnavailableException |
| log | | public void log(String msg)(Code) | | Writes the specified message to a servlet log file, prepended by the
servlet's name. See
ServletContext.log(String) .
Parameters:
msg - a String specifyingthe message to be written to the log file |
| log | | public void log(String message, Throwable t)(Code) | | Writes an explanatory message and a stack trace
for a given Throwable exception
to the servlet log file, prepended by the servlet's name.
See
ServletContext.log(StringThrowable) .
Parameters:
message - a String that describesthe error or exception
Parameters:
t - the java.lang.Throwable erroror exception |
| service | | abstract public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException(Code) | | Called by the servlet container to allow the servlet to respond to
a request. See
Servlet.service .
This method is declared abstract so subclasses, such as
HttpServlet, must override it.
Parameters:
req - the ServletRequest objectthat contains the client's request
Parameters:
res - the ServletResponse objectthat will contain the servlet's response
exception:
ServletException - if an exception occurs thatinterferes with the servlet'snormal operation occurred
exception:
IOException - if an input or outputexception occurs |
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