SLF4J探险之Marker接口

/**

• Markers are named objects used to enrich log statements. Conforming logging

• system Implementations of SLF4J determine how information conveyed by markers

• are used, if at all. In particular, many conforming logging systems ignore

• marker data.

• <p>

• Markers can contain references to other markers, which in turn may contain

• references of their own.

• @author Ceki Gülcü
  */
  public interface Marker extends Serializable {

  /**

  • This constant represents any marker, including a null marker.
    /
    public final String ANY_MARKER = "";

  /**

  • This constant represents any non-null marker.
    */
    public final String ANY_NON_NULL_MARKER = "+";

  /**

  • Get the name of this Marker.
  • @return name of marker
    */
    public String getName();

  /**

  • Add a reference to another Marker.
  • @param reference

  •            a reference to another marker
    

  • @throws IllegalArgumentException

  •             if 'reference' is null
    

  */
  public void add(Marker reference);

  /**

  • Remove a marker reference.
  • @param reference

  •            the marker reference to remove
    

  • @return true if reference could be found and removed, false otherwise.
    */
    public boolean remove(Marker reference);

  /**

  • @deprecated Replaced by {@link #hasReferences()}.
    */
    public boolean hasChildren();

  /**

  • Does this marker have any references?
  • @return true if this marker has one or more references, false otherwise.
    */
    public boolean hasReferences();

  /**

  • Returns an Iterator which can be used to iterate over the references of this
  • marker. An empty iterator is returned when this marker has no references.
  • @return Iterator over the references of this marker
    */
    public Iterator<Marker> iterator();

  /**

  • Does this marker contain a reference to the 'other' marker? Marker A is defined
  • to contain marker B, if A == B or if B is referenced by A, or if B is referenced
  • by any one of A's references (recursively).
  • @param other

  •            The marker to test for inclusion.
    

  • @throws IllegalArgumentException

  •             if 'other' is null
    

  • @return Whether this marker contains the other marker.
    */
    public boolean contains(Marker other);

  /**

  • Does this marker contain the marker named 'name'?
  • If 'name' is null the returned value is always false.
  • @param name The marker name to test for inclusion.
  • @return Whether this marker contains the other marker.
    */
    public boolean contains(String name);

  /**

  • Markers are considered equal if they have the same name.
  • @param o
  • @return true, if this.name equals o.name
  • @since 1.5.1
    */
    public boolean equals(Object o);

  /**

  • Compute the hash code based on the name of this marker.
  • Note that markers are considered equal if they have the same name.
  • @return the computed hashCode
  • @since 1.5.1
    */
    public int hashCode();

}