Apache Ant Listeners and Loggers

It is a feature which allows us to monitor the progress of Ant's progress during execution. Ant uses two concepts for monitoring: listeners and loggers and both are provided by Ant itself. See the all supported listeners below.

Listeners

build started
build finished
target started
target finished
task started
task finished
message logged

Loggers

loggers are used to extend the listeners capabilities. It has the various features, see below.

It log information to the console or the file specified using -logfile parameter.
It is logging level (-quite, -verbose, -debug) aware.
Emacs-mode aware

Apache Ant Listeners and Loggers interface can also be represented in UML. See an UML diagram below.

It is a UML diagram of BuildListener and BuildLogger interface.

Built-in Listeners and Loggers

DataType	Parameter	Description
org.apache.tools.ant.DefaultLogger	It is default logger and be overridden with the -logger command-line switch.	BuildLogger
org.apache.tools.ant.NoBannerLogger	It is used to omit output of empty target output.	BuildLogger
org.apache.tools.ant.listener.MailLogger	It extends DefaultLogger and generate the same output and send an email too.	BuildLogger
org.apache.tools.ant.listener.AnsiColorLogger	It is used to provide colors to the build output.	BuildLogger
org.apache.tools.ant.listener.Log4jListener	It is used to pass events to Apache Log4j logging.	BuildListener
org.apache.tools.ant.XmlLogger	It writes the build information to an XML file.	BuildLogger
org.apache.tools.ant.TimestampedLogger	It is used to print the time that a build finished.	BuildLogger
org.apache.tools.ant.listener.BigProjectLogger	It is used to print the project name every target has.	BuildLogger
org.apache.tools.ant.listener.SimpleBigProjectLogger	It prints the project name for subprojects only.	BuildLogger
org.apache.tools.ant.listener.ProfileLogger	It is a default logger with start times, end times and durations added for each task and target.	BuildLogger

Any number of build listeners can be attached to a project. We can use listener while running ant from the command line by specifying listener class.

Default Logger

DefaultLogger can be run using the below command, see we have passed DefaultLogger class here.

Mail Logger

MailLogger uses DefaultLogger to capture all output logs and send success and failure message through unique email lists.

MailLogger Class Properties

Property	Description	Required
MailLogger.mailhost	Mail server to use	No; default localhost
MailLogger.port	SMTP Port for the Mail server	No; default 25
MailLogger.user	user name for SMTP auth	Yes, if SMTP auth is required on your SMTP server
MailLogger.password	password for SMTP auth	Yes, if SMTP auth is required on your SMTP server
MailLogger.ssl	on or true if SSL is needed This feature requires JavaMail	No
MailLogger.from	Mail from address	Yes, if mail needs to be sent
MailLogger.replyto	Mail replyto address(es), comma-separated	No
MailLogger.success.to	Address(es) to send success messages to, comma-separated	Yes, if success mail is to be sent
MailLogger.success.cc	Address(es) to send success messages to carbon copy (cc), comma-separated	No
MailLogger.success.bcc	Address(es) to send success messages to blind carbon copy (bcc), comma-separated	No