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

Jackson Databind Source Code files are provided in the source packge (jackson-databind-2.14.0-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Databind Source Code below:

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

package com.fasterxml.jackson.databind.introspect;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.*;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.annotation.JsonInclude;

import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.annotation.JsonPOJOBuilder;
import com.fasterxml.jackson.databind.cfg.HandlerInstantiator;
import com.fasterxml.jackson.databind.cfg.MapperConfig;
import com.fasterxml.jackson.databind.type.TypeBindings;
import com.fasterxml.jackson.databind.util.Annotations;
import com.fasterxml.jackson.databind.util.ClassUtil;
import com.fasterxml.jackson.databind.util.Converter;

/**
 * Default {@link BeanDescription} implementation used by Jackson.
 *<p>
 * Although sub-classing is a theoretical possibility there are no known
 * use cases for that, nor is such usage tested or supported.
 * Separation from API is mostly to isolate some implementation details
 * here and keep API simple.
 */
public class BasicBeanDescription extends BeanDescription
{
    // since 2.9
    private final static Class<?>[] NO_VIEWS = new Class<?>[0];

    /*
    /**********************************************************
    /* General configuration
    /**********************************************************
     */

    /**
     * We will hold a reference to the collector in cases where
     * information is lazily accessed and constructed; properties
     * are only accessed when they are actually needed.
     */
    final protected POJOPropertiesCollector _propCollector;
    
    final protected MapperConfig<?> _config;

    final protected AnnotationIntrospector _annotationIntrospector;

    /*
    /**********************************************************
    /* Information about type itself
    /**********************************************************
     */
    
    /**
     * Information collected about the class introspected.
     */
    final protected AnnotatedClass _classInfo;

    /**
     * @since 2.9
     */
    protected Class<?>[] _defaultViews;

    /**
     * @since 2.9
     */
    protected boolean _defaultViewsResolved;

    /*
    /**********************************************************
    /* Member information
    /**********************************************************
     */

    /**
     * Properties collected for the POJO; initialized as needed.
     */
    protected List<BeanPropertyDefinition> _properties;

    /**
     * Details of Object Id to include, if any
     */
    protected ObjectIdInfo _objectIdInfo;

    /*
    /**********************************************************
    /* Life-cycle
    /**********************************************************
     */

    protected BasicBeanDescription(POJOPropertiesCollector coll,
            JavaType type, AnnotatedClass classDef)
    {
        super(type);
        _propCollector = coll;
        _config = coll.getConfig();
        // NOTE: null config only for some pre-constructed types
        if (_config == null) {
            _annotationIntrospector = null;
        } else {
            _annotationIntrospector = _config.getAnnotationIntrospector();
        }
        _classInfo = classDef;
    }

    /**
     * Alternate constructor used in cases where property information is not needed,
     * only class info.
     */
    protected BasicBeanDescription(MapperConfig<?> config,
            JavaType type, AnnotatedClass classDef, List<BeanPropertyDefinition> props)
    {
        super(type);
        _propCollector = null;
        _config = config;
        // NOTE: null config only for some pre-constructed types
        if (_config == null) {
            _annotationIntrospector = null;
        } else {
            _annotationIntrospector = _config.getAnnotationIntrospector();
        }
        _classInfo = classDef;
        _properties = props;
    }
    
    protected BasicBeanDescription(POJOPropertiesCollector coll)
    {
        this(coll, coll.getType(), coll.getClassDef());
        _objectIdInfo = coll.getObjectIdInfo();
    }

    /**
     * Factory method to use for constructing an instance to use for building
     * deserializers.
     */
    public static BasicBeanDescription forDeserialization(POJOPropertiesCollector coll) {
        return new BasicBeanDescription(coll);
    }

    /**
     * Factory method to use for constructing an instance to use for building
     * serializers.
     */
    public static BasicBeanDescription forSerialization(POJOPropertiesCollector coll) {
        return new BasicBeanDescription(coll);
    }

    /**
     * Factory method to use for constructing an instance to use for purposes
     * other than building serializers or deserializers; will only have information
     * on class, not on properties.
     */
    public static BasicBeanDescription forOtherUse(MapperConfig<?> config,
            JavaType type, AnnotatedClass ac)
    {
        return new BasicBeanDescription(config, type,
                ac, Collections.<BeanPropertyDefinition>emptyList());
    }

    protected List<BeanPropertyDefinition> _properties() {
        if (_properties == null) {
            _properties = _propCollector.getProperties();
        }
        return _properties;
    }

    /*
    /**********************************************************
    /* Limited modifications by core databind functionality
    /**********************************************************
     */

    /**
     * Method that can be used to prune unwanted properties, during
     * construction of serializers and deserializers.
     * Use with utmost care, if at all...
     * 
     * @since 2.1
     */
    public boolean removeProperty(String propName)
    {
        Iterator<BeanPropertyDefinition> it = _properties().iterator();
        while (it.hasNext()) {
            BeanPropertyDefinition prop = it.next();
            if (prop.getName().equals(propName)) {
                it.remove();
                return true;
            }
        }
        return false;
    }

    public boolean addProperty(BeanPropertyDefinition def)
    {
        // first: ensure we do not have such property
        if (hasProperty(def.getFullName())) {
            return false;
        }
        _properties().add(def);
        return true;
    }
    
    /**
     * @since 2.6
     */
    public boolean hasProperty(PropertyName name) {
        return findProperty(name) != null;
    }
    
    /**
     * @since 2.6
     */
    public BeanPropertyDefinition findProperty(PropertyName name)
    {
        for (BeanPropertyDefinition prop : _properties()) {
            if (prop.hasName(name)) {
                return prop;
            }
        }
        return null;
    }
    
    /*
    /**********************************************************
    /* Simple accessors from BeanDescription
    /**********************************************************
     */

    @Override
    public AnnotatedClass getClassInfo() { return _classInfo; }

    @Override
    public ObjectIdInfo getObjectIdInfo() { return  _objectIdInfo; }

    @Override
    public List<BeanPropertyDefinition> findProperties() {
        return _properties();
    }

    @Override // since 2.12
    public AnnotatedMember findJsonKeyAccessor() {
        return (_propCollector == null) ? null
                : _propCollector.getJsonKeyAccessor();
    }

    @Override
    @Deprecated // since 2.9
    public AnnotatedMethod findJsonValueMethod() {
        return (_propCollector == null) ? null
                : _propCollector.getJsonValueMethod();
    }

    @Override // since 2.9
    public AnnotatedMember findJsonValueAccessor() {
        return (_propCollector == null) ? null
                : _propCollector.getJsonValueAccessor();
    }
 
    @Override
    public Set<String> getIgnoredPropertyNames() {
        Set<String> ign = (_propCollector == null) ? null
                : _propCollector.getIgnoredPropertyNames();
        if (ign == null) {
            return Collections.emptySet();
        }
        return ign;
    }

    @Override
    public boolean hasKnownClassAnnotations() {
        return _classInfo.hasAnnotations();
    }

    @Override
    public Annotations getClassAnnotations() {
        return _classInfo.getAnnotations();
    }

    @Override
    @Deprecated // since 2.7
    public TypeBindings bindingsForBeanType() {
        return _type.getBindings();
    }

    @Override
    @Deprecated // since 2.8
    public JavaType resolveType(java.lang.reflect.Type jdkType) {
        // 06-Sep-2020, tatu: Careful wrt [databind#2846][databind#2821],
        //     call new method added in 2.12
        return _config.getTypeFactory().resolveMemberType(jdkType, _type.getBindings());
    }

    @Override
    public AnnotatedConstructor findDefaultConstructor() {
        return _classInfo.getDefaultConstructor();
    }

    @Override
    public AnnotatedMember findAnySetterAccessor() throws IllegalArgumentException
    {
        if (_propCollector != null) {
            AnnotatedMethod anyMethod = _propCollector.getAnySetterMethod();
            if (anyMethod != null) {
                // Also, let's be somewhat strict on how field name is to be
                // passed; String, Object make sense, others not so much.
    
                /* !!! 18-May-2009, tatu: how about enums? Can add support if
                 *  requested; easy enough for devs to add support within method.
                 */
                Class<?> type = anyMethod.getRawParameterType(0);
                if ((type != String.class) && (type != Object.class)) {
                    throw new IllegalArgumentException(String.format(
"Invalid 'any-setter' annotation on method '%s()': first argument not of type String or Object, but %s",
anyMethod.getName(), type.getName()));
                }
                return anyMethod;
            }
            AnnotatedMember anyField = _propCollector.getAnySetterField();
            if (anyField != null) {
                // For now let's require a Map; in future can add support for other
                // types like perhaps Iterable<Map.Entry>?
                Class<?> type = anyField.getRawType();
                if (!Map.class.isAssignableFrom(type)
                        && !JsonNode.class.isAssignableFrom(type)) {
                    throw new IllegalArgumentException(String.format(
"Invalid 'any-setter' annotation on field '%s': type is not instance of `java.util.Map` or `JsonNode`",
anyField.getName()));
                }
                return anyField;
            }
        }
        return null;
    }

    @Override
    public Map<Object, AnnotatedMember> findInjectables() {
        if (_propCollector != null) {
            return _propCollector.getInjectables();
        }
        return Collections.emptyMap();
    }

    @Override
    public List<AnnotatedConstructor> getConstructors() {
        return _classInfo.getConstructors();
    }

    @Override
    public List<AnnotatedAndMetadata<AnnotatedConstructor, JsonCreator.Mode>> getConstructorsWithMode() {
        List<AnnotatedConstructor> allCtors = _classInfo.getConstructors();
        if (allCtors.isEmpty()) {
            return Collections.emptyList();
        }
        List<AnnotatedAndMetadata<AnnotatedConstructor, JsonCreator.Mode>> result = new ArrayList<>();
        for (AnnotatedConstructor ctor : allCtors) {
            JsonCreator.Mode mode = _annotationIntrospector.findCreatorAnnotation(_config, ctor);
            if (mode == JsonCreator.Mode.DISABLED) {
                continue;
            }
            result.add(AnnotatedAndMetadata.of(ctor, mode));
        }
        return result;
    }

    @Override
    public Object instantiateBean(boolean fixAccess) {
        AnnotatedConstructor ac = _classInfo.getDefaultConstructor();
        if (ac == null) {
            return null;
        }
        if (fixAccess) {
            ac.fixAccess(_config.isEnabled(MapperFeature.OVERRIDE_PUBLIC_ACCESS_MODIFIERS));
        }
        try {
            return ac.call();
        } catch (Exception e) {
            Throwable t = e;
            while (t.getCause() != null) {
                t = t.getCause();
            }
            ClassUtil.throwIfError(t);
            ClassUtil.throwIfRTE(t);
            throw new IllegalArgumentException("Failed to instantiate bean of type "
                    +_classInfo.getAnnotated().getName()+": ("+t.getClass().getName()+") "
                    +ClassUtil.exceptionMessage(t), t);
        }
    }

    /*
    /**********************************************************
    /* Simple accessors, extended
    /**********************************************************
     */

    @Override
    public AnnotatedMethod findMethod(String name, Class<?>[] paramTypes) {
        return _classInfo.findMethod(name, paramTypes);
    }

    /*
    /**********************************************************
    /* General per-class annotation introspection
    /**********************************************************
     */

    @Override
    public JsonFormat.Value findExpectedFormat(JsonFormat.Value defValue)
    {
        // 15-Apr-2016, tatu: Let's check both per-type defaults and annotations; per-type
        //   defaults having higher precedence, so start with that
        if (_annotationIntrospector != null) {
            JsonFormat.Value v = _annotationIntrospector.findFormat(_classInfo);
            if (v != null) {
                if (defValue == null) {
                    defValue = v;
                } else {
                    defValue = defValue.withOverrides(v);
                }
            }
        }
        JsonFormat.Value v = _config.getDefaultPropertyFormat(_classInfo.getRawType());
        if (v != null) {
            if (defValue == null) {
                defValue = v;
            } else {
                defValue = defValue.withOverrides(v);
            }
        }
        return defValue;
    }

    @Override // since 2.9
    public Class<?>[] findDefaultViews()
    {
        if (!_defaultViewsResolved) {
            _defaultViewsResolved = true;
            Class<?>[] def = (_annotationIntrospector == null) ? null
                    : _annotationIntrospector.findViews(_classInfo);
            // one more twist: if default inclusion disabled, need to force empty set of views
            if (def == null) {
                if (!_config.isEnabled(MapperFeature.DEFAULT_VIEW_INCLUSION)) {
                    def = NO_VIEWS;
                }
            }
            _defaultViews = def;
        }
        return _defaultViews;
    }

    /*
    /**********************************************************
    /* Introspection for serialization
    /**********************************************************
     */

    @Override
    public Converter<Object,Object> findSerializationConverter()
    {
        if (_annotationIntrospector == null) {
            return null;
        }
        return _createConverter(_annotationIntrospector.findSerializationConverter(_classInfo));
    }

    /**
     * Method for determining whether null properties should be written
     * out for a Bean of introspected type. This is based on global
     * feature (lowest priority, passed as argument)
     * and per-class annotation (highest priority).
     */
    @Override
    public JsonInclude.Value findPropertyInclusion(JsonInclude.Value defValue) {
        if (_annotationIntrospector != null) {
            JsonInclude.Value incl = _annotationIntrospector.findPropertyInclusion(_classInfo);
            if (incl != null) {
                return (defValue == null) ? incl : defValue.withOverrides(incl);
            }
        }
        return defValue;
    }

    /**
     * Method used to locate the method of introspected class that
     * implements {@link com.fasterxml.jackson.annotation.JsonAnyGetter}.
     * If no such method exists null is returned.
     * If more than one are found, an exception is thrown.
     */
    @Override
    public AnnotatedMember findAnyGetter() throws IllegalArgumentException
    {
        if (_propCollector != null) {
            AnnotatedMember anyGetter = _propCollector.getAnyGetterMethod();
            if (anyGetter != null) {
                // For now let's require a Map; in future can add support for other
                // types like perhaps Iterable<Map.Entry>?
                Class<?> type = anyGetter.getRawType();
                if (!Map.class.isAssignableFrom(type)) {
                    throw new IllegalArgumentException(String.format(
                            "Invalid 'any-getter' annotation on method %s(): return type is not instance of java.util.Map",
                            anyGetter.getName()));
                }
                return anyGetter;
            }

            AnnotatedMember anyField = _propCollector.getAnyGetterField();
            if (anyField != null) {
                // For now let's require a Map; in future can add support for other
                // types like perhaps Iterable<Map.Entry>?
                Class<?> type = anyField.getRawType();
                if (!Map.class.isAssignableFrom(type)) {
                    throw new IllegalArgumentException(String.format(
                            "Invalid 'any-getter' annotation on field '%s': type is not instance of java.util.Map",
                            anyField.getName()));
                }
                return anyField;
            }
        }
        return null;
    }

    @Override
    public List<BeanPropertyDefinition> findBackReferences()
    {
        List<BeanPropertyDefinition> result = null;
        HashSet<String> names = null;
        for (BeanPropertyDefinition property : _properties()) {
            AnnotationIntrospector.ReferenceProperty refDef = property.findReferenceType();
            if ((refDef == null) || !refDef.isBackReference()) {
                continue;
            }
            final String refName = refDef.getName();
            if (result == null) {
                result = new ArrayList<BeanPropertyDefinition>();
                names = new HashSet<>();
                names.add(refName);
            } else {
                if (!names.add(refName)) {
                    throw new IllegalArgumentException("Multiple back-reference properties with name "+ClassUtil.name(refName));
                }
            }
            result.add(property);
        }
        return result;
    }

    @Deprecated // since 2.9
    @Override
    public Map<String,AnnotatedMember> findBackReferenceProperties()
    {
        List<BeanPropertyDefinition> props = findBackReferences();
        if (props == null) {
            return null;
        }
        Map<String,AnnotatedMember> result = new HashMap<>();
        for (BeanPropertyDefinition prop : props) {
            result.put(prop.getName(), prop.getMutator());
        }
        return result;
    }

    /*
    /**********************************************************
    /* Introspection for deserialization, factories
    /**********************************************************
     */

    @Override
    public List<AnnotatedMethod> getFactoryMethods()
    {
        // must filter out anything that clearly is not a factory method
        List<AnnotatedMethod> candidates = _classInfo.getFactoryMethods();
        if (candidates.isEmpty()) {
            return candidates;
        }
        List<AnnotatedMethod> result = null;
        for (AnnotatedMethod am : candidates) {
            if (isFactoryMethod(am)) {
                if (result == null) {
                    result = new ArrayList<AnnotatedMethod>();
                }
                result.add(am);
            }
        }
        if (result == null) {
            return Collections.emptyList();
        }
        return result;
    }

    @Override // since 2.13
    public List<AnnotatedAndMetadata<AnnotatedMethod, JsonCreator.Mode>> getFactoryMethodsWithMode()
    {
        List<AnnotatedMethod> candidates = _classInfo.getFactoryMethods();
        if (candidates.isEmpty()) {
            return Collections.emptyList();
        }
        List<AnnotatedAndMetadata<AnnotatedMethod, JsonCreator.Mode>> result = null;
        for (AnnotatedMethod am : candidates) {
            AnnotatedAndMetadata<AnnotatedMethod, JsonCreator.Mode> match
                = findFactoryMethodMetadata(am);
            if (match != null) {
                if (result == null) {
                    result = new ArrayList<>();
                }
                result.add(match);
            }
        }
        if (result == null) {
            return Collections.emptyList();
        }
        return result;
    }

    @Override
    @Deprecated // since 2.13
    public Constructor<?> findSingleArgConstructor(Class<?>... argTypes)
    {
        for (AnnotatedConstructor ac : _classInfo.getConstructors()) {
            // This list is already filtered to only include accessible
            if (ac.getParameterCount() == 1) {
                Class<?> actArg = ac.getRawParameterType(0);
                for (Class<?> expArg : argTypes) {
                    if (expArg == actArg) {
                        return ac.getAnnotated();
                    }
                }
            }
        }
        return null;
    }

    @Override
    @Deprecated // since 2.13
    public Method findFactoryMethod(Class<?>... expArgTypes)
    {
        // So, of all single-arg static methods:
        for (AnnotatedMethod am : _classInfo.getFactoryMethods()) {
            // 24-Oct-2016, tatu: Better ensure it only takes 1 arg, no matter what
            if (isFactoryMethod(am) && am.getParameterCount() == 1) {
                // And must take one of expected arg types (or supertype)
                Class<?> actualArgType = am.getRawParameterType(0);
                for (Class<?> expArgType : expArgTypes) {
                    // And one that matches what we would pass in
                    if (actualArgType.isAssignableFrom(expArgType)) {
                        return am.getAnnotated();
                    }
                }
            }
        }
        return null;
    }

    protected boolean isFactoryMethod(AnnotatedMethod am)
    {
        // First: return type must be compatible with the introspected class
        // (i.e. allowed to be sub-class, although usually is the same class)
        Class<?> rt = am.getRawReturnType();
        if (!getBeanClass().isAssignableFrom(rt)) {
            return false;
        }
        /* Also: must be a recognized factory method, meaning:
         * (a) marked with @JsonCreator annotation, or
         * (b) 1-argument "valueOf" (at this point, need not be public), or
         * (c) 1-argument "fromString()" AND takes {@code String} as the argument
         */
        JsonCreator.Mode mode = _annotationIntrospector.findCreatorAnnotation(_config, am);
        if ((mode != null) && (mode != JsonCreator.Mode.DISABLED)) {
            return true;
        }
        final String name = am.getName();
        // 24-Oct-2016, tatu: As per [databind#1429] must ensure takes exactly one arg
        if ("valueOf".equals(name)) {
            if (am.getParameterCount() == 1) {
                return true;
            }
        }
        // [databind#208] Also accept "fromString()", if takes String or CharSequence
        if ("fromString".equals(name)) {
            if (am.getParameterCount() == 1) {
                Class<?> cls = am.getRawParameterType(0);
                if (cls == String.class || CharSequence.class.isAssignableFrom(cls)) {
                    return true;
                }
            }
        }
        return false;
    }

    // @since 2.13
    protected AnnotatedAndMetadata<AnnotatedMethod, JsonCreator.Mode> findFactoryMethodMetadata(AnnotatedMethod am)
    {
        // First: return type must be compatible with the introspected class
        // (i.e. allowed to be sub-class, although usually is the same class)
        Class<?> rt = am.getRawReturnType();
        if (!getBeanClass().isAssignableFrom(rt)) {
            return null;
        }
        // Also: must be a recognized factory method, meaning:
        // (a) marked with @JsonCreator annotation, or
        // (b) 1-argument "valueOf" (at this point, need not be public), or
        // (c) 1-argument "fromString()" AND takes {@code String} as the argument
        JsonCreator.Mode mode = _annotationIntrospector.findCreatorAnnotation(_config, am);
        if (mode != null) {
            if (mode == JsonCreator.Mode.DISABLED) {
                return null;
            }
            return AnnotatedAndMetadata.of(am, mode);
        }
        final String name = am.getName();
        // 24-Oct-2016, tatu: As per [databind#1429] must ensure takes exactly one arg
        if ("valueOf".equals(name)) {
            if (am.getParameterCount() == 1) {
                return AnnotatedAndMetadata.of(am, mode);
            }
        }
        // [databind#208] Also accept "fromString()", if takes String or CharSequence
        if ("fromString".equals(name)) {
            if (am.getParameterCount() == 1) {
                Class<?> cls = am.getRawParameterType(0);
                if (cls == String.class || CharSequence.class.isAssignableFrom(cls)) {
                    return AnnotatedAndMetadata.of(am, mode);
                }
            }
        }
        return null;
    }

    /**
     * @deprecated since 2.8
     */
    @Deprecated // since 2.8, not used at least since 2.7
    protected PropertyName _findCreatorPropertyName(AnnotatedParameter param)
    {
        PropertyName name = _annotationIntrospector.findNameForDeserialization(param);
        if (name == null || name.isEmpty()) {
            String str = _annotationIntrospector.findImplicitPropertyName(param);
            if (str != null && !str.isEmpty()) {
                name = PropertyName.construct(str);
            }
        }
        return name;
    }

    /*
    /**********************************************************
    /* Introspection for deserialization, other
    /**********************************************************
     */

    @Override
    public Class<?> findPOJOBuilder() {
        return (_annotationIntrospector == null) ?
    			null : _annotationIntrospector.findPOJOBuilder(_classInfo);
    }

    @Override
    public JsonPOJOBuilder.Value findPOJOBuilderConfig()
    {
        return (_annotationIntrospector == null) ?
                null : _annotationIntrospector.findPOJOBuilderConfig(_classInfo);
    }

    @Override
    public Converter<Object,Object> findDeserializationConverter()
    {
        if (_annotationIntrospector == null) {
            return null;
        }
        return _createConverter(_annotationIntrospector.findDeserializationConverter(_classInfo));
    }

    @Override
    public String findClassDescription() {
        return (_annotationIntrospector == null) ?
                null : _annotationIntrospector.findClassDescription(_classInfo);
    }

    /*
    /**********************************************************
    /* Helper methods for field introspection
    /**********************************************************
     */

    /**
     * @param ignoredProperties (optional) names of properties to ignore;
     *   any fields that would be recognized as one of these properties
     *   is ignored.
     * @param forSerialization If true, will collect serializable property
     *    fields; if false, deserializable
     *
     * @return Ordered Map with logical property name as key, and
     *    matching field as value.
     *
     * @deprecated Since 2.7.2, does not seem to be used?
     */
    @Deprecated
    public LinkedHashMap<String,AnnotatedField> _findPropertyFields(
            Collection<String> ignoredProperties, boolean forSerialization)
    {
        LinkedHashMap<String,AnnotatedField> results = new LinkedHashMap<String,AnnotatedField>();
        for (BeanPropertyDefinition property : _properties()) {
            AnnotatedField f = property.getField();
            if (f != null) {
                String name = property.getName();
                if (ignoredProperties != null) {
                    if (ignoredProperties.contains(name)) {
                        continue;
                    }
                }
                results.put(name, f);
            }
        }
        return results;
    }

    /*
    /**********************************************************
    /* Helper methods, other
    /**********************************************************
     */
    
    @SuppressWarnings("unchecked")
    protected Converter<Object,Object> _createConverter(Object converterDef)
    {
        if (converterDef == null) {
            return null;
        }
        if (converterDef instanceof Converter<?,?>) {
            return (Converter<Object,Object>) converterDef;
        }
        if (!(converterDef instanceof Class)) {
            throw new IllegalStateException("AnnotationIntrospector returned Converter definition of type "
                    +converterDef.getClass().getName()+"; expected type Converter or Class<Converter> instead");
        }
        Class<?> converterClass = (Class<?>)converterDef;
        // there are some known "no class" markers to consider too:
        if (converterClass == Converter.None.class || ClassUtil.isBogusClass(converterClass)) {
            return null;
        }
        if (!Converter.class.isAssignableFrom(converterClass)) {
            throw new IllegalStateException("AnnotationIntrospector returned Class "
                    +converterClass.getName()+"; expected Class<Converter>");
        }
        HandlerInstantiator hi = _config.getHandlerInstantiator();
        Converter<?,?> conv = (hi == null) ? null : hi.converterInstance(_config, _classInfo, converterClass);
        if (conv == null) {
            conv = (Converter<?,?>) ClassUtil.createInstance(converterClass,
                    _config.canOverrideAccessModifiers());
        }
        return (Converter<Object,Object>) conv;
    }
}

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

Or download all of them as a single archive file:

File name: jackson-databind-2.14.0-sources.jar
File size: 1187952 bytes
Release date: 2022-11-05
Download 

⇒ Jackson Annotations Source Code

⇐ Download and Install Jackson Binary Package

⇑ Downloading and Reviewing jackson-*.jar

⇑⇑ Jackson - Java JSON library