Jackson is "the Java JSON library" or "the best JSON parser for Java". Or simply as "JSON for Java".

Jackson Annotations Source Code files are provided in the source packge (jackson-annotations-2.12.4-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Annotations Source Code below:

⏎ com/fasterxml/jackson/databind/introspect/CollectorBase.java

package com.fasterxml.jackson.databind.introspect;

import java.lang.annotation.Annotation;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import com.fasterxml.jackson.databind.AnnotationIntrospector;
import com.fasterxml.jackson.databind.util.ClassUtil;

// @since 2.9
class CollectorBase
{
    protected final static AnnotationMap[] NO_ANNOTATION_MAPS = new AnnotationMap[0];
    protected final static Annotation[] NO_ANNOTATIONS = new Annotation[0];

    protected final AnnotationIntrospector _intr;

    protected CollectorBase(AnnotationIntrospector intr) {
        _intr = intr;
    }

    // // // Annotation overrides ("mix over")

    protected final AnnotationCollector collectAnnotations(Annotation[] anns) {
        AnnotationCollector c = AnnotationCollector.emptyCollector();
        for (int i = 0, end = anns.length; i < end; ++i) {
            Annotation ann = anns[i];
            c = c.addOrOverride(ann);
            if (_intr.isAnnotationBundle(ann)) {
                c = collectFromBundle(c, ann);
            }
        }
        return c;
    }

    protected final AnnotationCollector collectAnnotations(AnnotationCollector c, Annotation[] anns) {
        for (int i = 0, end = anns.length; i < end; ++i) {
            Annotation ann = anns[i];
            c = c.addOrOverride(ann);
            if (_intr.isAnnotationBundle(ann)) {
                c = collectFromBundle(c, ann);
            }
        }
        return c;
    }

    protected final AnnotationCollector collectFromBundle(AnnotationCollector c, Annotation bundle) {
        Annotation[] anns = ClassUtil.findClassAnnotations(bundle.annotationType());
        for (int i = 0, end = anns.length; i < end; ++i) {
            Annotation ann = anns[i];
            // minor optimization: by-pass 2 common JDK meta-annotations
            if (_ignorableAnnotation(ann)) {
                continue;
            }
            if (_intr.isAnnotationBundle(ann)) {
                // 11-Apr-2017, tatu: Also must guard against recursive definitions...
                if (!c.isPresent(ann)) {
                    c = c.addOrOverride(ann);
                    c = collectFromBundle(c, ann);
                }
            } else {
                c = c.addOrOverride(ann);
            }
        }
        return c;
    }

    // // // Defaulting ("mix under")

    // Variant that only adds annotations that are missing
    protected final AnnotationCollector collectDefaultAnnotations(AnnotationCollector c,
            Annotation[] anns) {
        for (int i = 0, end = anns.length; i < end; ++i) {
            Annotation ann = anns[i];
            if (!c.isPresent(ann)) {
                c = c.addOrOverride(ann);
                if (_intr.isAnnotationBundle(ann)) {
                    c = collectDefaultFromBundle(c, ann);
                }
            }
        }
        return c;
    }

    protected final AnnotationCollector collectDefaultFromBundle(AnnotationCollector c,
            Annotation bundle) {
        Annotation[] anns = ClassUtil.findClassAnnotations(bundle.annotationType());
        for (int i = 0, end = anns.length; i < end; ++i) {
            Annotation ann = anns[i];
            // minor optimization: by-pass 2 common JDK meta-annotations
            if (_ignorableAnnotation(ann)) {
                continue;
            }
            // also only defaulting, not overrides:
            if (!c.isPresent(ann)) {
                c = c.addOrOverride(ann);
                if (_intr.isAnnotationBundle(ann)) {
                    c = collectFromBundle(c, ann);
                }
            }
        }
        return c;
    }
    
    protected final static boolean _ignorableAnnotation(Annotation a) {
        return (a instanceof Target) || (a instanceof Retention);
    }

    static AnnotationMap _emptyAnnotationMap() {
        return new AnnotationMap();
    }

    static AnnotationMap[] _emptyAnnotationMaps(int count) {
        if (count == 0) {
            return NO_ANNOTATION_MAPS;
        }
        AnnotationMap[] maps = new AnnotationMap[count];
        for (int i = 0; i < count; ++i) {
            maps[i] = _emptyAnnotationMap();
        }
        return maps;
    }
}

⏎ com/fasterxml/jackson/databind/introspect/CollectorBase.java

 

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