Class LogHandler

  extended by sunlabs.brazil.handler.LogHandler (view source)
All Implemented Interfaces:

public class LogHandler
extends Object
implements Handler

Handler for logging information about requests. Wraps another handler, and logs information about each HTTP request to a file.

Request properties:

The name of the handler to wrap. This can either be the token for the class, or the class name itself.
The name of the file to log the output to. If the file already exists, data is appended to it. If the file is removed, a new one is created. If no name is specified, one is invented that contains the name and port of the server. Unless an absolute path is specified, the log file is placed in the current directory.
The number of lines of logging output that may be buffered in memory before being written out to the log file. default to 25.
The format of the output string. Embedded strings of the form "%X" are replaced, based on the following values for "X": Defaults to "%u;%t:%d:%b".
If specified This string is tacked onto the end of the "format" string. Entries in the Request Properties may be included using ${...} substitutions.
If specified This string is tacked onto the end of the "props" string. Entries in the HTTPrequest headers may be included using ${...} substitutions.
if present, this is output as the first line of the file

See the ChainSawHandler for generating standard format log files.

Field Summary
 File file
 int flush
 String format
 Handler handler
 String headers
 String props
 String title
Constructor Summary
Method Summary
 boolean init(Server server, String prefix)
          Initializes the handler.
 boolean respond(Request request)
          Dispatch the request to the handler.
static String subst(Request request, String format, long duration)
          Format a string.
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail


public Handler handler


public String props


public String headers


public String format


public String title


public int flush


public File file
Constructor Detail


public LogHandler()
Method Detail


public boolean init(Server server,
                    String prefix)
Description copied from interface: Handler
Initializes the handler.

Specified by:
init in interface Handler
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.
true if this Handler initialized successfully, false otherwise. If false is returned, this Handler should not be used.


public boolean respond(Request request)
                throws IOException
Dispatch the request to the handler. Log information if dispatched handler returns true.

Specified by:
respond in interface Handler
request - The Request object that represents the HTTP request.
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.
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.


public static String subst(Request request,
                           String format,
                           long duration)
Format a string. Replace %X constructs.

Version Kenai-svn-r24, Generated 08/18/09
Copyright (c) 2001-2009, Sun Microsystems.