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package javax.annotation.processing;

import javax.tools.Diagnostic;
import javax.lang.model.element.*;


A Messager provides the way for an annotation processor to report error messages, warnings, and other notices. Elements, annotations, and annotation values can be passed to provide a location hint for the message. However, such location hints may be unavailable or only approximate. 
Printing a message with an error kind will raise an error. 
Note that the messages "printed" by methods in this interface may or may not appear as textual output to a location like System.out or System.err. Implementations may choose to present this information in a different fashion, such as messages in a window. 
Author:Joseph D. Darcy, Scott Seligman, Peter von der Ahé
See Also:
Since:1.6
/**
 * A {@code Messager} provides the way for an annotation processor to
 * report error messages, warnings, and other notices.  Elements,
 * annotations, and annotation values can be passed to provide a
 * location hint for the message.  However, such location hints may be
 * unavailable or only approximate.
 *
 * <p>Printing a message with an {@linkplain
 * javax.tools.Diagnostic.Kind#ERROR error kind} will {@linkplain
 * RoundEnvironment#errorRaised raise an error}.
 *
 * <p>Note that the messages &quot;printed&quot; by methods in this
 * interface may or may not appear as textual output to a location
 * like {@link System#out} or {@link System#err}.  Implementations may
 * choose to present this information in a different fashion, such as
 * messages in a window.
 *
 * @author Joseph D. Darcy
 * @author Scott Seligman
 * @author Peter von der Ah&eacute;
 * @see ProcessingEnvironment#getLocale
 * @since 1.6
 */
public interface Messager {
    
Prints a message of the specified kind.

Params:
  • kind – the kind of message
  • msg –  the message, or an empty string if none
/**
     * Prints a message of the specified kind.
     *
     * @param kind the kind of message
     * @param msg  the message, or an empty string if none
     */
    void printMessage(Diagnostic.Kind kind, CharSequence msg);

    
Prints a message of the specified kind at the location of the
element.

Params:
  • kind – the kind of message
  • msg –  the message, or an empty string if none
  • e –    the element to use as a position hint
/**
     * Prints a message of the specified kind at the location of the
     * element.
     *
     * @param kind the kind of message
     * @param msg  the message, or an empty string if none
     * @param e    the element to use as a position hint
     */
    void printMessage(Diagnostic.Kind kind, CharSequence msg, Element e);

    
Prints a message of the specified kind at the location of the
annotation mirror of the annotated element.

Params:
  • kind – the kind of message
  • msg –  the message, or an empty string if none
  • e –    the annotated element
  • a –    the annotation to use as a position hint
/**
     * Prints a message of the specified kind at the location of the
     * annotation mirror of the annotated element.
     *
     * @param kind the kind of message
     * @param msg  the message, or an empty string if none
     * @param e    the annotated element
     * @param a    the annotation to use as a position hint
     */
    void printMessage(Diagnostic.Kind kind, CharSequence msg, Element e, AnnotationMirror a);

    
Prints a message of the specified kind at the location of the
annotation value inside the annotation mirror of the annotated
element.

Params:
  • kind – the kind of message
  • msg –  the message, or an empty string if none
  • e –    the annotated element
  • a –    the annotation containing the annotation value
  • v –    the annotation value to use as a position hint
/**
     * Prints a message of the specified kind at the location of the
     * annotation value inside the annotation mirror of the annotated
     * element.
     *
     * @param kind the kind of message
     * @param msg  the message, or an empty string if none
     * @param e    the annotated element
     * @param a    the annotation containing the annotation value
     * @param v    the annotation value to use as a position hint
     */
    void printMessage(Diagnostic.Kind kind,
                      CharSequence msg,
                      Element e,
                      AnnotationMirror a,
                      AnnotationValue v);
}