DefaultLogger (Apache Ant API)
Date: 2016-04-24

org.apache.tools.ant

## Class DefaultLogger

- java.lang.Object
- - org.apache.tools.ant.DefaultLogger

- All Implemented Interfaces:
    java.util.EventListener, BuildListener, BuildLogger
  Direct Known Subclasses:
    AnsiColorLogger, MailLogger, NoBannerLogger, ProfileLogger, SilentLogger, TimestampedLogger

      public class DefaultLogger
      extends java.lang.Object
      implements BuildLogger

  Writes build events to a PrintStream. Currently, it only writes which targets are being executed, and any messages that get logged.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `protected boolean` | `emacsMode` Whether or not to use emacs-style output
    `protected java.io.PrintStream` | `err` PrintStream to write error messages to
    `static int` | `LEFT_COLUMN_SIZE` Size of left-hand column for right-justified task name.
    `protected static java.lang.String` | `lSep` Line separator
    `protected int` | `msgOutputLevel` Lowest level of message to write out
    `protected java.io.PrintStream` | `out` PrintStream to write non-error messages to

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `DefaultLogger()` Sole constructor.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `buildFinished(BuildEvent event)` Prints whether the build succeeded or failed, any errors the occurred during the build, and how long the build took.
    `void` | `buildStarted(BuildEvent event)` Responds to a build being started by just remembering the current time.
    `protected java.lang.String` | `extractProjectName(BuildEvent event)` Get the project name or null
    `protected static java.lang.String` | `formatTime(long millis)` Convenience method to format a specified length of time.
    `protected java.lang.String` | `getBuildFailedMessage()` This is an override point: the message that indicates whether a build failed.
    `protected java.lang.String` | `getBuildSuccessfulMessage()` This is an override point: the message that indicates that a build succeeded.
    `protected java.lang.String` | `getTimestamp()` Get the current time.
    `protected void` | `log(java.lang.String message)` Empty implementation which allows subclasses to receive the same output that is generated here.
    `void` | `messageLogged(BuildEvent event)` Logs a message, if the priority is suitable.
    `protected void` | `printMessage(java.lang.String message, java.io.PrintStream stream, int priority)` Prints a message to a PrintStream.
    `void` | `setEmacsMode(boolean emacsMode)` Sets this logger to produce emacs (and other editor) friendly output.
    `void` | `setErrorPrintStream(java.io.PrintStream err)` Sets the output stream to which this logger is to send error messages.
    `void` | `setMessageOutputLevel(int level)` Sets the highest level of message this logger should respond to.
    `void` | `setOutputPrintStream(java.io.PrintStream output)` Sets the output stream to which this logger is to send its output.
    `void` | `targetFinished(BuildEvent event)` No-op implementation.
    `void` | `targetStarted(BuildEvent event)` Logs a message to say that the target has started if this logger allows information-level messages.
    `void` | `taskFinished(BuildEvent event)` No-op implementation.
    `void` | `taskStarted(BuildEvent event)` No-op implementation.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Field Detail

    - #### LEFT_COLUMN_SIZE

          public static final int LEFT_COLUMN_SIZE

      Size of left-hand column for right-justified task name.
      See Also:
        `messageLogged(BuildEvent)`, Constant Field Values

    - #### out

          protected java.io.PrintStream out

      PrintStream to write non-error messages to

    - #### err

          protected java.io.PrintStream err

      PrintStream to write error messages to

    - #### msgOutputLevel

          protected int msgOutputLevel

      Lowest level of message to write out

    - #### lSep

          protected static final java.lang.String lSep

      Line separator

    - #### emacsMode

          protected boolean emacsMode

      Whether or not to use emacs-style output

  - ### Constructor Detail

    - #### DefaultLogger

          public DefaultLogger()

      Sole constructor.

  - ### Method Detail

    - #### setMessageOutputLevel

          public void setMessageOutputLevel(int level)

      Sets the highest level of message this logger should respond to. Only messages with a message level lower than or equal to the given level should be written to the log.

      Constants for the message levels are in the `Project` class. The order of the levels, from least to most verbose, is `MSG_ERR`, `MSG_WARN`, `MSG_INFO`, `MSG_VERBOSE`, `MSG_DEBUG`.

      The default message level for DefaultLogger is Project.MSG_ERR.

      Specified by:
        `setMessageOutputLevel` in interface `BuildLogger`
      Parameters:
        `level` - the logging level for the logger.

    - #### setOutputPrintStream

          public void setOutputPrintStream(java.io.PrintStream output)

      Sets the output stream to which this logger is to send its output.
      Specified by:
        `setOutputPrintStream` in interface `BuildLogger`
      Parameters:
        `output` - The output stream for the logger. Must not be `null`.

    - #### setErrorPrintStream

          public void setErrorPrintStream(java.io.PrintStream err)

      Sets the output stream to which this logger is to send error messages.
      Specified by:
        `setErrorPrintStream` in interface `BuildLogger`
      Parameters:
        `err` - The error stream for the logger. Must not be `null`.

    - #### setEmacsMode

          public void setEmacsMode(boolean emacsMode)

      Sets this logger to produce emacs (and other editor) friendly output.
      Specified by:
        `setEmacsMode` in interface `BuildLogger`
      Parameters:
        `emacsMode` - `true` if output is to be unadorned so that emacs and other editors can parse files names, etc.

    - #### buildStarted

          public void buildStarted(BuildEvent event)

      Responds to a build being started by just remembering the current time.
      Specified by:
        `buildStarted` in interface `BuildListener`
      Parameters:
        `event` - Ignored.

    - #### buildFinished

          public void buildFinished(BuildEvent event)

      Prints whether the build succeeded or failed, any errors the occurred during the build, and how long the build took.
      Specified by:
        `buildFinished` in interface `BuildListener`
      Parameters:
        `event` - An event with any relevant extra information. Must not be `null`.
      See Also:
        `BuildEvent.getException()`

    - #### getBuildFailedMessage

          protected java.lang.String getBuildFailedMessage()

      This is an override point: the message that indicates whether a build failed. Subclasses can change/enhance the message.
      Returns:
        The classic "BUILD FAILED"

    - #### getBuildSuccessfulMessage

          protected java.lang.String getBuildSuccessfulMessage()

      This is an override point: the message that indicates that a build succeeded. Subclasses can change/enhance the message.
      Returns:
        The classic "BUILD SUCCESSFUL"

    - #### targetStarted

          public void targetStarted(BuildEvent event)

      Logs a message to say that the target has started if this logger allows information-level messages.
      Specified by:
        `targetStarted` in interface `BuildListener`
      Parameters:
        `event` - An event with any relevant extra information. Must not be `null`.
      See Also:
        `BuildEvent.getTarget()`

    - #### targetFinished

          public void targetFinished(BuildEvent event)

      No-op implementation.
      Specified by:
        `targetFinished` in interface `BuildListener`
      Parameters:
        `event` - Ignored.
      See Also:
        `BuildEvent.getException()`

    - #### taskStarted

          public void taskStarted(BuildEvent event)

      No-op implementation.
      Specified by:
        `taskStarted` in interface `BuildListener`
      Parameters:
        `event` - Ignored.
      See Also:
        `BuildEvent.getTask()`

    - #### taskFinished

          public void taskFinished(BuildEvent event)

      No-op implementation.
      Specified by:
        `taskFinished` in interface `BuildListener`
      Parameters:
        `event` - Ignored.
      See Also:
        `BuildEvent.getException()`

    - #### messageLogged

          public void messageLogged(BuildEvent event)

      Logs a message, if the priority is suitable. In non-emacs mode, task level messages are prefixed by the task name which is right-justified.
      Specified by:
        `messageLogged` in interface `BuildListener`
      Parameters:
        `event` - A BuildEvent containing message information. Must not be `null`.
      See Also:
        `BuildEvent.getMessage()`, `BuildEvent.getException()`, `BuildEvent.getPriority()`

    - #### formatTime

          protected static java.lang.String formatTime(long millis)

      Convenience method to format a specified length of time.
      Parameters:
        `millis` - Length of time to format, in milliseconds.
      Returns:
        the time as a formatted string.
      See Also:
        `DateUtils.formatElapsedTime(long)`

    - #### printMessage

          protected void printMessage(java.lang.String message,
                          java.io.PrintStream stream,
                          int priority)

      Prints a message to a PrintStream.
      Parameters:
        `message` - The message to print. Should not be `null`.
        `stream` - A PrintStream to print the message to. Must not be `null`.
        `priority` - The priority of the message. (Ignored in this implementation.)

    - #### log

          protected void log(java.lang.String message)

      Empty implementation which allows subclasses to receive the same output that is generated here.
      Parameters:
        `message` - Message being logged. Should not be `null`.

    - #### getTimestamp

          protected java.lang.String getTimestamp()

      Get the current time.
      Returns:
        the current time as a formatted string.
      Since:
        Ant1.7.1

    - #### extractProjectName

          protected java.lang.String extractProjectName(BuildEvent event)

      Get the project name or null
      Parameters:
        `event` - the event
      Returns:
        the project that raised this event
      Since:
        Ant1.7.1