Module java.logging

Class Level

java.lang.Object
java.util.logging.Level
All Implemented Interfaces:
Serializable

public class Level
extends Object
implements Serializable
The Level class defines a set of standard logging levels that can be used to control logging output. The logging Level objects are ordered and are specified by ordered integers. Enabling logging at a given level also enables logging at all higher levels.

Clients should normally use the predefined Level constants such as Level.SEVERE.

The levels in descending order are:

  • SEVERE (highest value)
  • WARNING
  • INFO
  • CONFIG
  • FINE
  • FINER
  • FINEST (lowest value)
In addition there is a level OFF that can be used to turn off logging, and a level ALL that can be used to enable logging of all messages.

It is possible for third parties to define additional logging levels by subclassing Level. In such cases subclasses should take care to chose unique integer level values and to ensure that they maintain the Object uniqueness property across serialization by defining a suitable readResolve method.

Since:
1.4
See Also:
Serialized Form
  • Field Summary

    Fields
    Modifier and Type Field Description
    static Level ALL
    ALL indicates that all messages should be logged.
    static Level CONFIG
    CONFIG is a message level for static configuration messages.
    static Level FINE
    FINE is a message level providing tracing information.
    static Level FINER
    FINER indicates a fairly detailed tracing message.
    static Level FINEST
    FINEST indicates a highly detailed tracing message.
    static Level INFO
    INFO is a message level for informational messages.
    static Level OFF
    OFF is a special level that can be used to turn off logging.
    static Level SEVERE
    SEVERE is a message level indicating a serious failure.
    static Level WARNING
    WARNING is a message level indicating a potential problem.
  • Constructor Summary

    Constructors
    Modifier Constructor Description
    protected Level​(String name, int value)
    Create a named Level with a given integer value.
    protected Level​(String name, int value, String resourceBundleName)
    Create a named Level with a given integer value and a given localization resource name.
  • Method Summary

    Modifier and Type Method Description
    boolean equals​(Object ox)
    Compare two objects for value equality.
    String getLocalizedName()
    Return the localized string name of the Level, for the current default locale.
    String getName()
    Return the non-localized string name of the Level.
    String getResourceBundleName()
    Return the level's localization resource bundle name, or null if no localization bundle is defined.
    int hashCode()
    Generate a hashcode.
    int intValue()
    Get the integer value for this level.
    static Level parse​(String name)
    Parse a level name string into a Level.
    String toString()
    Returns a string representation of this Level.

    Methods declared in class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait
  • Field Details

    • OFF

      public static final Level OFF
      OFF is a special level that can be used to turn off logging. This level is initialized to Integer.MAX_VALUE.
    • SEVERE

      public static final Level SEVERE
      SEVERE is a message level indicating a serious failure.

      In general SEVERE messages should describe events that are of considerable importance and which will prevent normal program execution. They should be reasonably intelligible to end users and to system administrators. This level is initialized to 1000.

    • WARNING

      public static final Level WARNING
      WARNING is a message level indicating a potential problem.

      In general WARNING messages should describe events that will be of interest to end users or system managers, or which indicate potential problems. This level is initialized to 900.

    • INFO

      public static final Level INFO
      INFO is a message level for informational messages.

      Typically INFO messages will be written to the console or its equivalent. So the INFO level should only be used for reasonably significant messages that will make sense to end users and system administrators. This level is initialized to 800.

    • CONFIG

      public static final Level CONFIG
      CONFIG is a message level for static configuration messages.

      CONFIG messages are intended to provide a variety of static configuration information, to assist in debugging problems that may be associated with particular configurations. For example, CONFIG message might include the CPU type, the graphics depth, the GUI look-and-feel, etc. This level is initialized to 700.

    • FINE

      public static final Level FINE
      FINE is a message level providing tracing information.

      All of FINE, FINER, and FINEST are intended for relatively detailed tracing. The exact meaning of the three levels will vary between subsystems, but in general, FINEST should be used for the most voluminous detailed output, FINER for somewhat less detailed output, and FINE for the lowest volume (and most important) messages.

      In general the FINE level should be used for information that will be broadly interesting to developers who do not have a specialized interest in the specific subsystem.

      FINE messages might include things like minor (recoverable) failures. Issues indicating potential performance problems are also worth logging as FINE. This level is initialized to 500.

    • FINER

      public static final Level FINER
      FINER indicates a fairly detailed tracing message. By default logging calls for entering, returning, or throwing an exception are traced at this level. This level is initialized to 400.
    • FINEST

      public static final Level FINEST
      FINEST indicates a highly detailed tracing message. This level is initialized to 300.
    • ALL

      public static final Level ALL
      ALL indicates that all messages should be logged. This level is initialized to Integer.MIN_VALUE.
  • Constructor Details

    • Level

      protected Level​(String name, int value)
      Create a named Level with a given integer value.

      Note that this constructor is "protected" to allow subclassing. In general clients of logging should use one of the constant Level objects such as SEVERE or FINEST. However, if clients need to add new logging levels, they may subclass Level and define new constants.

      Parameters:
      name - the name of the Level, for example "SEVERE".
      value - an integer value for the level.
      Throws:
      NullPointerException - if the name is null
    • Level

      protected Level​(String name, int value, String resourceBundleName)
      Create a named Level with a given integer value and a given localization resource name.
      Parameters:
      name - the name of the Level, for example "SEVERE".
      value - an integer value for the level.
      resourceBundleName - name of a resource bundle to use in localizing the given name. If the resourceBundleName is null or an empty string, it is ignored.
      Throws:
      NullPointerException - if the name is null
  • Method Details

    • getResourceBundleName

      public String getResourceBundleName()
      Return the level's localization resource bundle name, or null if no localization bundle is defined.
      Returns:
      localization resource bundle name
    • getName

      public String getName()
      Return the non-localized string name of the Level.
      Returns:
      non-localized name
    • getLocalizedName

      public String getLocalizedName()
      Return the localized string name of the Level, for the current default locale.

      If no localization information is available, the non-localized name is returned.

      Returns:
      localized name
    • toString

      public final String toString()
      Returns a string representation of this Level.
      Overrides:
      toString in class Object
      Returns:
      the non-localized name of the Level, for example "INFO".
    • intValue

      public final int intValue()
      Get the integer value for this level. This integer value can be used for efficient ordering comparisons between Level objects.
      Returns:
      the integer value for this level.
    • parse

      public static Level parse​(String name) throws IllegalArgumentException
      Parse a level name string into a Level.

      The argument string may consist of either a level name or an integer value.

      For example:

      • "SEVERE"
      • "1000"

      Parameters:
      name - string to be parsed
      Returns:
      The parsed value. Passing an integer that corresponds to a known name (e.g., 700) will return the associated name (e.g., CONFIG). Passing an integer that does not (e.g., 1) will return a new level name initialized to that value.
      Throws:
      NullPointerException - if the name is null
      IllegalArgumentException - if the value is not valid. Valid values are integers between Integer.MIN_VALUE and Integer.MAX_VALUE, and all known level names. Known names are the levels defined by this class (e.g., FINE, FINER, FINEST), or created by this class with appropriate package access, or new levels defined or created by subclasses.
    • equals

      public boolean equals​(Object ox)
      Compare two objects for value equality.
      Overrides:
      equals in class Object
      Parameters:
      ox - the reference object with which to compare.
      Returns:
      true if and only if the two objects have the same level value.
      See Also:
      Object.hashCode(), HashMap
    • hashCode

      public int hashCode()
      Generate a hashcode.
      Overrides:
      hashCode in class Object
      Returns:
      a hashcode based on the level value
      See Also:
      Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)