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/cfg/MapperConfigBase.java

package com.fasterxml.jackson.databind.cfg;

import java.text.DateFormat;
import java.util.*;

import com.fasterxml.jackson.annotation.*;
import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
import com.fasterxml.jackson.core.Base64Variant;

import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.introspect.ClassIntrospector;
import com.fasterxml.jackson.databind.introspect.ClassIntrospector.MixInResolver;
import com.fasterxml.jackson.databind.introspect.AccessorNamingStrategy;
import com.fasterxml.jackson.databind.introspect.AnnotatedClass;
import com.fasterxml.jackson.databind.introspect.SimpleMixInResolver;
import com.fasterxml.jackson.databind.introspect.VisibilityChecker;
import com.fasterxml.jackson.databind.jsontype.SubtypeResolver;
import com.fasterxml.jackson.databind.jsontype.TypeResolverBuilder;
import com.fasterxml.jackson.databind.type.TypeFactory;
import com.fasterxml.jackson.databind.util.ClassUtil;
import com.fasterxml.jackson.databind.util.RootNameLookup;

@SuppressWarnings("serial")
public abstract class MapperConfigBase<CFG extends ConfigFeature,
    T extends MapperConfigBase<CFG,T>>
    extends MapperConfig<T>
    implements java.io.Serializable
{
    /**
     * @since 2.9
     */
    protected final static ConfigOverride EMPTY_OVERRIDE = ConfigOverride.empty();

    private final static long DEFAULT_MAPPER_FEATURES = MapperFeature.collectLongDefaults();

    /**
     * @since 2.9
     */
    private final static long AUTO_DETECT_MASK =
            MapperFeature.AUTO_DETECT_FIELDS.getLongMask()
            | MapperFeature.AUTO_DETECT_GETTERS.getLongMask()
            | MapperFeature.AUTO_DETECT_IS_GETTERS.getLongMask()
            | MapperFeature.AUTO_DETECT_SETTERS.getLongMask()
            | MapperFeature.AUTO_DETECT_CREATORS.getLongMask()
            ;

    /*
    /**********************************************************
    /* Immutable config
    /**********************************************************
     */

    /**
     * Mix-in annotation mappings to use, if any: immutable,
     * cannot be changed once defined.
     * 
     * @since 2.6
     */
    protected final SimpleMixInResolver _mixIns;

    /**
     * Registered concrete subtypes that can be used instead of (or
     * in addition to) ones declared using annotations.
     *<p>
     * Note that instances are stateful and as such may need to be copied,
     * and may NOT be demoted down to {@link BaseSettings}.
     */
    protected final SubtypeResolver _subtypeResolver;

    /**
     * Explicitly defined root name to use, if any; if empty
     * String, will disable root-name wrapping; if null, will
     * use defaults
     */
    protected final PropertyName _rootName;

    /**
     * View to use for filtering out properties to serialize
     * or deserialize.
     * Null if none (will also be assigned null if <code>Object.class</code>
     * is defined), meaning that all properties are to be included.
     */
    protected final Class<?> _view;

    /**
     * Contextual attributes accessible (get and set) during processing,
     * on per-call basis.
     * 
     * @since 2.3
     */
    protected final ContextAttributes _attributes;

    /**
     * Simple cache used for finding out possible root name for root name
     * wrapping.
     *<p>
     * Note that instances are stateful (for caching) and as such may need to be copied,
     * and may NOT be demoted down to {@link BaseSettings}.
     *
     * @since 2.6
     */
    protected final RootNameLookup _rootNames;

    /**
     * Configuration overrides to apply, keyed by type of property.
     *
     * @since 2.8
     */
    protected final ConfigOverrides _configOverrides;

    /**
     * Set of {@link DatatypeFeature}s enabled.
     *
     * @since 2.14
     */
    protected final DatatypeFeatures _datatypeFeatures;

    /*
    /**********************************************************
    /* Construction
    /**********************************************************
     */

    /**
     * Constructor used when creating a new instance (compared to
     * that of creating fluent copies)
     *
     * @since 2.14
     */
    protected MapperConfigBase(BaseSettings base,
            SubtypeResolver str, SimpleMixInResolver mixins, RootNameLookup rootNames,
            ConfigOverrides configOverrides, DatatypeFeatures datatypeFeatures)
    {
        super(base, DEFAULT_MAPPER_FEATURES);
        _mixIns = mixins;
        _subtypeResolver = str;
        _rootNames = rootNames;
        _rootName = null;
        _view = null;
        // default to "no attributes"
        _attributes = ContextAttributes.getEmpty();
        _configOverrides = configOverrides;
        _datatypeFeatures = datatypeFeatures;
    }

    /**
     * Copy constructor usually called to make a copy for use by
     * ObjectMapper that is copied.
     *
     * @since 2.14
     */
    protected MapperConfigBase(MapperConfigBase<CFG,T> src,
            SubtypeResolver str, SimpleMixInResolver mixins, RootNameLookup rootNames,
            ConfigOverrides configOverrides)
    {
        // 18-Apr-2018, tatu: [databind#1898] need to force copying of `ClassIntrospector`
        //    (to clear its cache) to avoid leakage
        super(src, src._base.copy());
        _mixIns = mixins;
        _subtypeResolver = str;
        _rootNames = rootNames;
        _rootName = src._rootName;
        _view = src._view;
        _attributes = src._attributes;
        _configOverrides = configOverrides;
        _datatypeFeatures = src._datatypeFeatures;
    }

    /**
     * Pass-through constructor used when no changes are needed to the
     * base class.
     */
    protected MapperConfigBase(MapperConfigBase<CFG,T> src)
    {
        super(src);
        _mixIns = src._mixIns;
        _subtypeResolver = src._subtypeResolver;
        _rootNames = src._rootNames;
        _rootName = src._rootName;
        _view = src._view;
        _attributes = src._attributes;
        _configOverrides = src._configOverrides;
        _datatypeFeatures = src._datatypeFeatures;
    }

    protected MapperConfigBase(MapperConfigBase<CFG,T> src, BaseSettings base)
    {
        super(src, base);
        _mixIns = src._mixIns;
        _subtypeResolver = src._subtypeResolver;
        _rootNames = src._rootNames;
        _rootName = src._rootName;
        _view = src._view;
        _attributes = src._attributes;
        _configOverrides = src._configOverrides;
        _datatypeFeatures = src._datatypeFeatures;
    }

    protected MapperConfigBase(MapperConfigBase<CFG,T> src, long mapperFeatures)
    {
        super(src, mapperFeatures);
        _mixIns = src._mixIns;
        _subtypeResolver = src._subtypeResolver;
        _rootNames = src._rootNames;
        _rootName = src._rootName;
        _view = src._view;
        _attributes = src._attributes;
        _configOverrides = src._configOverrides;
        _datatypeFeatures = src._datatypeFeatures;
    }

    protected MapperConfigBase(MapperConfigBase<CFG,T> src, SubtypeResolver str) {
        super(src);
        _mixIns = src._mixIns;
        _subtypeResolver = str;
        _rootNames = src._rootNames;
        _rootName = src._rootName;
        _view = src._view;
        _attributes = src._attributes;
        _configOverrides = src._configOverrides;
        _datatypeFeatures = src._datatypeFeatures;
    }

    protected MapperConfigBase(MapperConfigBase<CFG,T> src, PropertyName rootName) {
        super(src);
        _mixIns = src._mixIns;
        _subtypeResolver = src._subtypeResolver;
        _rootNames = src._rootNames;
        _rootName = rootName;
        _view = src._view;
        _attributes = src._attributes;
        _configOverrides = src._configOverrides;
        _datatypeFeatures = src._datatypeFeatures;
    }

    protected MapperConfigBase(MapperConfigBase<CFG,T> src, Class<?> view)
    {
        super(src);
        _mixIns = src._mixIns;
        _subtypeResolver = src._subtypeResolver;
        _rootNames = src._rootNames;
        _rootName = src._rootName;
        _view = view;
        _attributes = src._attributes;
        _configOverrides = src._configOverrides;
        _datatypeFeatures = src._datatypeFeatures;
    }

    /**
     * @since 2.1
     */
    protected MapperConfigBase(MapperConfigBase<CFG,T> src, SimpleMixInResolver mixins)
    {
        super(src);
        _mixIns = mixins;
        _subtypeResolver = src._subtypeResolver;
        _rootNames = src._rootNames;
        _rootName = src._rootName;
        _view = src._view;
        _attributes = src._attributes;
        _configOverrides = src._configOverrides;
        _datatypeFeatures = src._datatypeFeatures;
    }

    /**
     * @since 2.3
     */
    protected MapperConfigBase(MapperConfigBase<CFG,T> src, ContextAttributes attr)
    {
        super(src);
        _mixIns = src._mixIns;
        _subtypeResolver = src._subtypeResolver;
        _rootNames = src._rootNames;
        _rootName = src._rootName;
        _view = src._view;
        _attributes = attr;
        _configOverrides = src._configOverrides;
        _datatypeFeatures = src._datatypeFeatures;
    }

    /**
     * @since 2.14
     */
    protected MapperConfigBase(MapperConfigBase<CFG,T> src, DatatypeFeatures datatypeFeatures)
    {
        super(src);
        _mixIns = src._mixIns;
        _subtypeResolver = src._subtypeResolver;
        _rootNames = src._rootNames;
        _rootName = src._rootName;
        _view = src._view;
        _attributes = src._attributes;
        _configOverrides = src._configOverrides;
        _datatypeFeatures = datatypeFeatures;
    }

    /*
    /**********************************************************************
    /* Abstract fluent factory methods to be implemented by subtypes
    /**********************************************************************
     */

    /**
     * @since 2.9 (in this case, demoted from sub-classes)
     */
    protected abstract T _withBase(BaseSettings newBase);

    /**
     * @since 2.9 (in this case, demoted from sub-classes)
     */
    protected abstract T _withMapperFeatures(long mapperFeatures);

    /**
     * @since 2.14
     */
    protected abstract T _with(DatatypeFeatures dtFeatures);

    /**
     * @since 2.14
     */
    protected DatatypeFeatures _datatypeFeatures() {
        return _datatypeFeatures;
    }

    /*
    /**********************************************************************
    /* Additional shared fluent factory methods; MapperFeatures
    /**********************************************************************
     */

    /**
     * Fluent factory method that will construct and return a new configuration
     * object instance with specified features enabled.
     */
    @SuppressWarnings("unchecked")
    @Override
    public final T with(MapperFeature... features)
    {
        long newMapperFlags = _mapperFeatures;
        for (MapperFeature f : features) {
            newMapperFlags |= f.getLongMask();
        }
        if (newMapperFlags == _mapperFeatures) {
            return (T) this;
        }
        return _withMapperFeatures(newMapperFlags);
    }

    /**
     * Fluent factory method that will construct and return a new configuration
     * object instance with specified features disabled.
     */
    @SuppressWarnings("unchecked")
    @Override
    public final T without(MapperFeature... features)
    {
        long newMapperFlags = _mapperFeatures;
        for (MapperFeature f : features) {
             newMapperFlags &= ~f.getLongMask();
        }
        if (newMapperFlags == _mapperFeatures) {
            return (T) this;
        }
        return _withMapperFeatures(newMapperFlags);
    }

    @SuppressWarnings("unchecked")
    @Override
    public final T with(MapperFeature feature, boolean state)
    {
        long newMapperFlags;
        if (state) {
            newMapperFlags = _mapperFeatures | feature.getLongMask();
        } else {
            newMapperFlags = _mapperFeatures & ~feature.getLongMask();
        }
        if (newMapperFlags == _mapperFeatures) {
            return (T) this;
        }
        return _withMapperFeatures(newMapperFlags);
    }

    /*
    /**********************************************************************
    /* Additional shared fluent factory methods; DatatypeFeatures
    /**********************************************************************
     */
    
    /**
     * Fluent factory method that will return a configuration
     * object instance with specified feature enabled: this may be
     * {@code this} instance (if no changes effected), or a newly
     * constructed instance.
     */
    public final T with(DatatypeFeature feature) {
        return _with(_datatypeFeatures().with(feature));
    }

    /**
     * Fluent factory method that will return a configuration
     * object instance with specified features enabled: this may be
     * {@code this} instance (if no changes effected), or a newly
     * constructed instance.
     */
    public final T withFeatures(DatatypeFeature... features) {
        return _with(_datatypeFeatures().withFeatures(features));
    }

    /**
     * Fluent factory method that will return a configuration
     * object instance with specified feature disabled: this may be
     * {@code this} instance (if no changes effected), or a newly
     * constructed instance.
     */
    public final T without(DatatypeFeature feature) {
        return _with(_datatypeFeatures().without(feature));
    }

    /**
     * Fluent factory method that will return a configuration
     * object instance with specified features disabled: this may be
     * {@code this} instance (if no changes effected), or a newly
     * constructed instance.
     */
    public final T withoutFeatures(DatatypeFeature... features) {
        return _with(_datatypeFeatures().withoutFeatures(features));
    }
    
    /**
     * Fluent factory method that will construct and return a new configuration
     * object instance with specified features disabled.
     */

    public final T with(DatatypeFeature feature, boolean state)
    {
        DatatypeFeatures features = _datatypeFeatures();
        features = state ? features.with(feature) : features.without(feature);
        return _with(features);
    }

    /*
    /**********************************************************************
    /* Additional shared fluent factory methods; introspectors
    /**********************************************************************
     */
    
    /**
     * Method for constructing and returning a new instance with different
     * {@link AnnotationIntrospector} to use (replacing old one).
     *<p>
     * NOTE: make sure to register new instance with <code>ObjectMapper</code>
     * if directly calling this method.
     */
    public final T with(AnnotationIntrospector ai) {
        return _withBase(_base.withAnnotationIntrospector(ai));
    }

    /**
     * Method for constructing and returning a new instance with additional
     * {@link AnnotationIntrospector} appended (as the lowest priority one)
     */
    public final T withAppendedAnnotationIntrospector(AnnotationIntrospector ai) {
        return _withBase(_base.withAppendedAnnotationIntrospector(ai));
    }

    /**
     * Method for constructing and returning a new instance with additional
     * {@link AnnotationIntrospector} inserted (as the highest priority one)
     */
    public final T withInsertedAnnotationIntrospector(AnnotationIntrospector ai) {
        return _withBase(_base.withInsertedAnnotationIntrospector(ai));
    }
    
    /**
     * Method for constructing and returning a new instance with different
     * {@link ClassIntrospector}
     * to use.
     *<p>
     * NOTE: make sure to register new instance with <code>ObjectMapper</code>
     * if directly calling this method.
     */
    public final T with(ClassIntrospector ci) {
        return _withBase(_base.withClassIntrospector(ci));
    }

    /*
    /**********************************************************************
    /* Additional shared fluent factory methods; attributes
    /**********************************************************************
     */

    /**
     * Method for constructing an instance that has specified
     * contextual attributes.
     * 
     * @since 2.3
     */
    public abstract T with(ContextAttributes attrs);

    /**
     * Method for constructing an instance that has only specified
     * attributes, removing any attributes that exist before the call.
     * 
     * @since 2.3
     */
    public T withAttributes(Map<?,?> attributes) {
        return with(getAttributes().withSharedAttributes(attributes));
    }
    
    /**
     * Method for constructing an instance that has specified
     * value for attribute for given key.
     * 
     * @since 2.3
     */
    public T withAttribute(Object key, Object value) {
        return with(getAttributes().withSharedAttribute(key, value));
    }

    /**
     * Method for constructing an instance that has no
     * value for attribute for given key.
     * 
     * @since 2.3
     */
    public T withoutAttribute(Object key) {
        return with(getAttributes().withoutSharedAttribute(key));
    }

    /*
    /**********************************************************************
    /* Additional shared fluent factory methods; factories
    /**********************************************************************
     */

    /**
     * Method for constructing and returning a new instance with different
     * {@link TypeFactory}
     * to use.
     */
    public final T with(TypeFactory tf) {
        return _withBase( _base.withTypeFactory(tf));
    }

    /**
     * Method for constructing and returning a new instance with different
     * {@link TypeResolverBuilder} to use.
     */
    public final T with(TypeResolverBuilder<?> trb) {
        return _withBase(_base.withTypeResolverBuilder(trb));
    }

    /**
     * Method for constructing and returning a new instance with different
     * {@link PropertyNamingStrategy}
     * to use.
     *<p>
     * NOTE: make sure to register new instance with <code>ObjectMapper</code>
     * if directly calling this method.
     */
    public final T with(PropertyNamingStrategy pns) {
        return _withBase(_base.withPropertyNamingStrategy(pns));
    }

    /**
     * Method for constructing and returning a new instance with different
     * {@link PropertyNamingStrategy}
     * to use.
     *
     * @since 2.12
     */
    public final T with(AccessorNamingStrategy.Provider p) {
        return _withBase(_base.withAccessorNaming(p));
    }

    /**
     * Method for constructing and returning a new instance with different
     * {@link HandlerInstantiator}
     * to use.
     *<p>
     * NOTE: make sure to register new instance with <code>ObjectMapper</code>
     * if directly calling this method.
     */
    public final T with(HandlerInstantiator hi) {
        return _withBase(_base.withHandlerInstantiator(hi));
    }

    /*
    /**********************************************************************
    /* Additional shared fluent factory methods; other
    /**********************************************************************
     */

    /**
     * Method for constructing and returning a new instance with different
     * default {@link Base64Variant} to use with base64-encoded binary values.
     */
    public final T with(Base64Variant base64) {
        return _withBase(_base.with(base64));
    }

    /**
     * Method for constructing and returning a new instance with different
     * {@link DateFormat}
     * to use.
     *<p>
     * NOTE: non-final since <code>SerializationConfig</code> needs to override this
     */
    public T with(DateFormat df) {
        return _withBase(_base.withDateFormat(df));
    }

    /**
     * Method for constructing and returning a new instance with different
     * default {@link java.util.Locale} to use for formatting.
     */
    public final T with(Locale l) {
        return _withBase(_base.with(l));
    }

    /**
     * Method for constructing and returning a new instance with different
     * default {@link java.util.TimeZone} to use for formatting of date values.
     */
    public final T with(TimeZone tz) {
        return _withBase(_base.with(tz));
    }

    /**
     * Method for constructing and returning a new instance with different
     * root name to use (none, if null).
     *<p>
     * Note that when a root name is set to a non-Empty String, this will automatically force use
     * of root element wrapping with given name. If empty String passed, will
     * disable root name wrapping; and if null used, will instead use
     * <code>SerializationFeature</code> to determine if to use wrapping, and annotation
     * (or default name) for actual root name to use.
     * 
     * @param rootName to use: if null, means "use default" (clear setting);
     *   if empty String ("") means that no root name wrapping is used;
     *   otherwise defines root name to use.
     *   
     * @since 2.6
     */
    public abstract T withRootName(PropertyName rootName);

    public T withRootName(String rootName) {
        if (rootName == null) {
            return withRootName((PropertyName) null);
        }
        return withRootName(PropertyName.construct(rootName));
    }
    
    /**
     * Method for constructing and returning a new instance with different
     * {@link SubtypeResolver}
     * to use.
     *<p>
     * NOTE: make sure to register new instance with <code>ObjectMapper</code>
     * if directly calling this method.
     */
    public abstract T with(SubtypeResolver str);

    /**
     * Method for constructing and returning a new instance with different
     * view to use.
     */
    public abstract T withView(Class<?> view);

    /*
    /**********************************************************************
    /* Simple accessors
    /**********************************************************************
     */

    /**
     * Accessor for object used for finding out all reachable subtypes
     * for supertypes; needed when a logical type name is used instead
     * of class name (or custom scheme).
     */
    @Override
    public final SubtypeResolver getSubtypeResolver() {
        return _subtypeResolver;
    }

    /**
     * @deprecated Since 2.6 use {@link #getFullRootName} instead.
     */
    @Deprecated // since 2.6
    public final String getRootName() {
        return (_rootName == null) ? null : _rootName.getSimpleName();
    }

    /**
     * @since 2.6
     */
    public final PropertyName getFullRootName() {
        return _rootName;
    }

    @Override
    public final Class<?> getActiveView() {
        return _view;
    }

    @Override
    public final ContextAttributes getAttributes() {
        return _attributes;
    }

    /*
    /**********************************************************************
    /* Configuration access; default/overrides
    /**********************************************************************
     */

    @Override
    public final ConfigOverride getConfigOverride(Class<?> type) {
        ConfigOverride override = _configOverrides.findOverride(type);
        return (override == null) ? EMPTY_OVERRIDE : override;
    }

    @Override
    public final ConfigOverride findConfigOverride(Class<?> type) {
        return _configOverrides.findOverride(type);
    }

    @Override
    public final JsonInclude.Value getDefaultPropertyInclusion() {
        return _configOverrides.getDefaultInclusion();
    }

    @Override
    public final JsonInclude.Value getDefaultPropertyInclusion(Class<?> baseType) {
        JsonInclude.Value v = getConfigOverride(baseType).getInclude();
        JsonInclude.Value def = getDefaultPropertyInclusion();
        if (def == null) {
            return v;
        }
        return def.withOverrides(v);
    }

    @Override
    public final JsonInclude.Value getDefaultInclusion(Class<?> baseType,
            Class<?> propertyType) {
        JsonInclude.Value v = getConfigOverride(propertyType).getIncludeAsProperty();
        JsonInclude.Value def = getDefaultPropertyInclusion(baseType);
        if (def == null) {
            return v;
        }
        return def.withOverrides(v);
    }

    @Override
    public final JsonFormat.Value getDefaultPropertyFormat(Class<?> type) {
        return _configOverrides.findFormatDefaults(type);
    }

    @Override
    public final JsonIgnoreProperties.Value getDefaultPropertyIgnorals(Class<?> type) {
        ConfigOverride overrides = _configOverrides.findOverride(type);
        if (overrides != null) {
            JsonIgnoreProperties.Value v = overrides.getIgnorals();
            if (v != null) {
                return v;
            }
        }
        // 01-May-2015, tatu: Could return `Value.empty()` but for now `null`
        //   seems simpler as callers can avoid processing.
        return null;
    }

    @Override
    public final JsonIgnoreProperties.Value getDefaultPropertyIgnorals(Class<?> baseType,
            AnnotatedClass actualClass)
    {
        AnnotationIntrospector intr = getAnnotationIntrospector();
        JsonIgnoreProperties.Value base = (intr == null) ? null
                : intr.findPropertyIgnoralByName(this, actualClass);
        JsonIgnoreProperties.Value overrides = getDefaultPropertyIgnorals(baseType);
        return JsonIgnoreProperties.Value.merge(base, overrides);
    }

    @Override
    public final JsonIncludeProperties.Value getDefaultPropertyInclusions(Class<?> baseType,
            AnnotatedClass actualClass)
    {
        AnnotationIntrospector intr = getAnnotationIntrospector();
        return (intr == null) ? null : intr.findPropertyInclusionByName(this, actualClass);
    }

    @Override
    public final VisibilityChecker<?> getDefaultVisibilityChecker()
    {
        VisibilityChecker<?> vchecker = _configOverrides.getDefaultVisibility();
        // then global overrides (disabling)
        // 05-Mar-2018, tatu: As per [databind#1947], need to see if any disabled
        if ((_mapperFeatures & AUTO_DETECT_MASK) != AUTO_DETECT_MASK) {
            if (!isEnabled(MapperFeature.AUTO_DETECT_FIELDS)) {
                vchecker = vchecker.withFieldVisibility(Visibility.NONE);
            }
            if (!isEnabled(MapperFeature.AUTO_DETECT_GETTERS)) {
                vchecker = vchecker.withGetterVisibility(Visibility.NONE);
            }
            if (!isEnabled(MapperFeature.AUTO_DETECT_IS_GETTERS)) {
                vchecker = vchecker.withIsGetterVisibility(Visibility.NONE);
            }
            if (!isEnabled(MapperFeature.AUTO_DETECT_SETTERS)) {
                vchecker = vchecker.withSetterVisibility(Visibility.NONE);
            }
            if (!isEnabled(MapperFeature.AUTO_DETECT_CREATORS)) {
                vchecker = vchecker.withCreatorVisibility(Visibility.NONE);
            }
        }
        return vchecker;
    }

    @Override // since 2.9
    public final VisibilityChecker<?> getDefaultVisibilityChecker(Class<?> baseType,
            AnnotatedClass actualClass)
    {
        // 14-Apr-2021, tatu: [databind#3117] JDK types should be limited
        //    to "public-only" regardless of settings for other types
        VisibilityChecker<?> vc;

        if (ClassUtil.isJDKClass(baseType)) {
            vc = VisibilityChecker.Std.allPublicInstance();
        } else {
            vc = getDefaultVisibilityChecker();
        }
        AnnotationIntrospector intr = getAnnotationIntrospector();
        if (intr != null) {
            vc = intr.findAutoDetectVisibility(actualClass, vc);
        }
        ConfigOverride overrides = _configOverrides.findOverride(baseType);
        if (overrides != null) {
            vc = vc.withOverrides(overrides.getVisibility()); // ok to pass null
        }
        return vc;
    }

    @Override
    public final JsonSetter.Value getDefaultSetterInfo() {
        return _configOverrides.getDefaultSetterInfo();
    }

    @Override
    public Boolean getDefaultMergeable() {
        return _configOverrides.getDefaultMergeable();
    }

    @Override
    public Boolean getDefaultMergeable(Class<?> baseType) {
        Boolean b;
        ConfigOverride cfg = _configOverrides.findOverride(baseType);
        if (cfg != null) {
            b = cfg.getMergeable();
            if (b != null) {
                return b;
            }
        }
        return _configOverrides.getDefaultMergeable();
    }

    /*
    /**********************************************************************
    /* Other config access
    /**********************************************************************
     */

    @Override
    public PropertyName findRootName(JavaType rootType) {
        if (_rootName != null) {
            return _rootName;
        }
        return _rootNames.findRootName(rootType, this);
    }

    @Override
    public PropertyName findRootName(Class<?> rawRootType) {
        if (_rootName != null) {
            return _rootName;
        }
        return _rootNames.findRootName(rawRootType, this);
    }

    /*
    /**********************************************************************
    /* ClassIntrospector.MixInResolver impl:
    /**********************************************************************
     */

    /**
     * Method that will check if there are "mix-in" classes (with mix-in
     * annotations) for given class
     */
    @Override
    public final Class<?> findMixInClassFor(Class<?> cls) {
        return _mixIns.findMixInClassFor(cls);
    }

    // Not really relevant here (should not get called)
    @Override
    public MixInResolver copy() {
        throw new UnsupportedOperationException();
    }
    
    /**
     * Test-only method -- does not reflect possibly open-ended set that external
     * mix-in resolver might provide.
     */
    public final int mixInCount() {
        return _mixIns.localSize();
    }
}

⏎ com/fasterxml/jackson/databind/cfg/MapperConfigBase.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

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⇑⇑ Jackson - Java JSON library