JsonIgnore.java

package com.fasterxml.jackson.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Marker annotation that indicates that the annotated method or field is to be
 * ignored by introspection-based serialization and deserialization
 * functionality. That is, it should not be consider a "getter", "setter" or
 * "creator".
 * <p>
 * In addition, starting with Jackson 1.9, if this is the only annotation
 * associated with a property, it will also cause cause the whole property to be
 * ignored: that is, if setter has this annotation and getter has no
 * annotations, getter is also effectively ignored. It is still possible for
 * different accessors to use different annotations; so if only "getter" is to
 * be ignored, other accessors (setter or field) would need explicit annotation
 * to prevent ignoral (usually {@link JsonProperty}).
 * <p>
 * For example, a "getter" method that would otherwise denote a property (like,
 * say, "getValue" to suggest property "value") to serialize, would be ignored
 * and no such property would be output unless another annotation defines
 * alternative method to use.
 * <p>
 * Before version 1.9, this annotation worked purely on method-by-method (or
 * field-by-field) basis; annotation on one method or field did not imply
 * ignoring other methods or fields. However, with version 1.9 and above,
 * annotations associated with various accessors (getter, setter, field,
 * constructor parameter) of a logical property are combined; meaning that
 * annotations in one (say, setter) can have effects on all of them (if getter
 * or field has nothing indicating otherwise).
 * <p>
 * Annotation is usually used just a like a marker annotation, that is, without
 * explicitly defining 'value' argument (which defaults to <code>true</code>):
 * but argument can be explicitly defined. This can be done to override an
 * existing JsonIgnore by explicitly defining one with 'false' argument.
 * <p>
 * Annotation is similar to {@link javax.xml.bind.annotation.XmlTransient}
 */
@Target({ ElementType.ANNOTATION_TYPE, ElementType.METHOD, ElementType.CONSTRUCTOR, ElementType.FIELD })
@Retention(RetentionPolicy.RUNTIME)
@JacksonAnnotation
public @interface JsonIgnore {
	/**
	 * Optional argument that defines whether this annotation is active or not.
	 * The only use for value 'false' if for overriding purposes (which is not
	 * needed often); most likely it is needed for use with "mix-in annotations"
	 * (aka "annotation overrides"). For most cases, however, default value of
	 * "true" is just fine and should be omitted.
	 */
	boolean value() default true;
}