sunlabs.brazil.beanshell
Class BeanShellHandler

java.lang.Object
  sunlabs.brazil.beanshell.BeanShellHandler (view source)

All Implemented Interfaces:

Handler

public class BeanShellHandler
extends Object
implements Handler

The BeanShellHandler permits handlers to be written in "beanshell".

The reason one would write a BeanShell handler, instead of coding the handler directly in Java, is for ease of handler development and maintanence; a BeanShell handler may be modified at will while the server is running, permitting rapid development. Once functional, the code is easily converted into a traditional handler.

The beanshell script is expected to contain both init and respond methods, which are invoked by the server just like an ordinary handler.

script

The name of the BeanShell script to use as the handler. Normally, the script is read only once. (defaults to prefix.bsh)

root

The script directory, if the script is a relative file name. If the "root" property under the prefix is not found, the global "root" property is used. If the global "root" property is not found, the current directory is used.

debug

If this configuration parameter is present, the script is re-read on each request, and a new interperter is created and initialized. The call to init is deferred until request time, and called before each call to respond.

This allows beanshell scripts to be debugged interatively from scratch.

Constructor Summary

BeanShellHandler()

Method Summary

boolean	init(Server server, String prefix) Initializes the handler.
boolean	respond(Request request) Responds to an HTTP request.

Methods inherited from class java.lang.Object

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

Constructor Detail

BeanShellHandler

public BeanShellHandler()

Method Detail

init

public boolean init(Server server,
                    String prefix)

Description copied from interface: Handler

Initializes the handler.

Specified by:

init in interface Handler

Parameters:

server - The HTTP server that created this Handler. Typical Handlers will use Server.props to obtain run-time configuration information.

prefix - The handlers name. The string this Handler may prepend to all of the keys that it uses to extract configuration information from Server.props. This is set (by the Server and ChainHandler) to help avoid configuration parameter namespace collisions.

Returns:

true if this Handler initialized successfully, false otherwise. If false is returned, this Handler should not be used.

respond

public boolean respond(Request request)
                throws IOException

Description copied from interface: Handler

Responds to an HTTP request.

Specified by:

respond in interface Handler

Parameters:

request - The Request object that represents the HTTP request.

Returns:

true if the request was handled. A request was handled if a response was supplied to the client, typically by calling Request.sendResponse() or Request.sendError.

Throws:

IOException - if there was an I/O error while sending the response to the client. Typically, in that case, the Server will (try to) send an error message to the client and then close the client's connection.

The IOException should not be used to silently ignore problems such as being unable to access some server-side resource (for example getting a FileNotFoundException due to not being able to open a file). In that case, the Handler's duty is to turn that IOException into a HTTP response indicating, in this case, that a file could not be found.