The interface for writing HTTP handlers. Provides basic functionality
to accept HTTP requests and dispatch to methods to handle the request.
The init(Server, String) method is called before this
Handler processes the first HTTP request, to allow it to
prepare itself, such as by allocating any resources needed for the
lifetime of the Handler.
The respond(Request) method is called to handle an HTTP request.
This method and all methods it calls must be thread-safe since they may
handle HTTP requests from multiple sockets concurrently. However, each
concurrent request gets its own individual Request object.
server - The HTTP server that created this Handler.
Typical Handlers will use Server.props
to obtain run-time configuration information.
prefix - A prefix that 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.
For example, if a Handler uses the property
"account", and the specified prefix is "bank.", then the
Handler should actually examine the property
"bank.account" in Server.props.
Returns:
true if this Handler initialized
successfully, false otherwise. If
false is returned, this Handler
should not be used.
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.
