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/MapperConfig.java

package com.fasterxml.jackson.databind.cfg;

import java.text.DateFormat;
import java.util.Locale;
import java.util.TimeZone;

import com.fasterxml.jackson.annotation.*;

import com.fasterxml.jackson.core.Base64Variant;
import com.fasterxml.jackson.core.SerializableString;
import com.fasterxml.jackson.core.io.SerializedString;
import com.fasterxml.jackson.core.type.TypeReference;

import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.introspect.AccessorNamingStrategy;
import com.fasterxml.jackson.databind.introspect.Annotated;
import com.fasterxml.jackson.databind.introspect.AnnotatedClass;
import com.fasterxml.jackson.databind.introspect.ClassIntrospector;
import com.fasterxml.jackson.databind.introspect.NopAnnotationIntrospector;
import com.fasterxml.jackson.databind.introspect.VisibilityChecker;
import com.fasterxml.jackson.databind.jsontype.DefaultBaseTypeLimitingValidator;
import com.fasterxml.jackson.databind.jsontype.PolymorphicTypeValidator;
import com.fasterxml.jackson.databind.jsontype.SubtypeResolver;
import com.fasterxml.jackson.databind.jsontype.TypeIdResolver;
import com.fasterxml.jackson.databind.jsontype.TypeResolverBuilder;
import com.fasterxml.jackson.databind.jsontype.impl.LaissezFaireSubTypeValidator;
import com.fasterxml.jackson.databind.type.TypeFactory;
import com.fasterxml.jackson.databind.util.ClassUtil;

/**
 * Interface that defines functionality accessible through both
 * serialization and deserialization configuration objects;
 * accessors to mode-independent configuration settings
 * and such.
 * In addition, shared features are defined
 * in {@link MapperFeature}.
 *<p>
 * Small part of implementation is included here by aggregating
 * {@link BaseSettings} instance that contains configuration
 * that is shared between different types of instances.
 */
public abstract class MapperConfig<T extends MapperConfig<T>>
    implements ClassIntrospector.MixInResolver,
        java.io.Serializable
{
    private static final long serialVersionUID = 2L; // since 2.9

    /**
     * @since 2.7
     */
    protected final static JsonInclude.Value EMPTY_INCLUDE = JsonInclude.Value.empty();

    /**
     * @since 2.7
     */
    protected final static JsonFormat.Value EMPTY_FORMAT = JsonFormat.Value.empty();

    /**
     * Set of shared mapper features enabled.
     *<p>
     * NOTE: changed from {@code int} (in Jackson 2.12 and prior} to {@code long}
     * (2.13 and later)
     */
    protected final long _mapperFeatures;

    /**
     * Immutable container object for simple configuration settings.
     */
    protected final BaseSettings _base;

    /*
    /**********************************************************
    /* Life-cycle: constructors
    /**********************************************************
     */

    protected MapperConfig(BaseSettings base, long mapperFeatures)
    {
        _base = base;
        _mapperFeatures = mapperFeatures;
    }

    protected MapperConfig(MapperConfig<T> src, long mapperFeatures)
    {
        _base = src._base;
        _mapperFeatures = mapperFeatures;
    }

    protected MapperConfig(MapperConfig<T> src, BaseSettings base)
    {
        _base = base;
        _mapperFeatures = src._mapperFeatures;
    }
    
    protected MapperConfig(MapperConfig<T> src)
    {
        _base = src._base;
        _mapperFeatures = src._mapperFeatures;
    }

    /**
     * Method that calculates bit set (flags) of all features that
     * are enabled by default.
     */
    public static <F extends Enum<F> & ConfigFeature> int collectFeatureDefaults(Class<F> enumClass)
    {
        int flags = 0;
        for (F value : enumClass.getEnumConstants()) {
            if (value.enabledByDefault()) {
                flags |= value.getMask();
            }
        }
        return flags;
    }

    /*
    /**********************************************************
    /* Life-cycle: factory methods
    /**********************************************************
     */
    
    /**
     * Method for constructing and returning a new instance with specified
     * mapper features enabled.
     */
    public abstract T with(MapperFeature... features);

    /**
     * Method for constructing and returning a new instance with specified
     * mapper features disabled.
     */
    public abstract T without(MapperFeature... features);

    /**
     * @since 2.3
     */
    public abstract T with(MapperFeature feature, boolean state);
    
    /*
    /**********************************************************
    /* Configuration: simple features
    /**********************************************************
     */

    /**
     * Accessor for simple mapper features (which are shared for
     * serialization, deserialization)
     */
    public final boolean isEnabled(MapperFeature f) {
        return f.enabledIn(_mapperFeatures);
    }

    /**
     * "Bulk" access method for checking that all features specified by
     * mask are enabled.
     * 
     * @since 2.3
     *
     * @deprecated Since 2.13 -- no replacement
     */
    @Deprecated
    public final boolean hasMapperFeatures(int featureMask) {
        return (_mapperFeatures & featureMask) == featureMask;
    }
    
    /**
     * Method for determining whether annotation processing is enabled or not
     * (default settings are typically that it is enabled; must explicitly disable).
     * 
     * @return True if annotation processing is enabled; false if not
     */
    public final boolean isAnnotationProcessingEnabled() {
        return isEnabled(MapperFeature.USE_ANNOTATIONS);
    }

    /**
     * Accessor for determining whether it is ok to try to force override of access
     * modifiers to be able to get or set values of non-public Methods, Fields;
     * to invoke non-public Constructors, Methods; or to instantiate non-public
     * Classes. By default this is enabled, but on some platforms it needs to be
     * prevented since if this would violate security constraints and cause failures.
     * 
     * @return True if access modifier overriding is allowed (and may be done for
     *   any Field, Method, Constructor or Class); false to prevent any attempts
     *   to override.
     */
    public final boolean canOverrideAccessModifiers() {
        return isEnabled(MapperFeature.CAN_OVERRIDE_ACCESS_MODIFIERS);
    }

    /**
     * Accessor for checking whether default settings for property handling
     * indicate that properties should be alphabetically ordered or not.
     */
    public final boolean shouldSortPropertiesAlphabetically() {
        return isEnabled(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY);
    }

    /**
     * Accessor for checking whether configuration indicates that
     * "root wrapping" (use of an extra property/name pair at root level)
     * is expected or not.
     */
    public abstract boolean useRootWrapping();

    /*
    /**********************************************************
    /* Configuration: factory methods
    /**********************************************************
     */

    /**
     * Method for constructing a specialized textual object that can typically
     * be serialized faster than basic {@link java.lang.String} (depending
     * on escaping needed if any, char-to-byte encoding if needed).
     * 
     * @param src Text to represent
     * 
     * @return Optimized text object constructed
     * 
     * @since 2.4
     */
    public SerializableString compileString(String src) {
        /* 20-Jan-2014, tatu: For now we will just construct it directly, but
         *    in future should allow overriding to support non-standard extensions
         *    to be used by extensions like Afterburner.
         */
        return new SerializedString(src);
    }
    
    /*
    /**********************************************************
    /* Configuration: introspectors, mix-ins
    /**********************************************************
     */
    
    public ClassIntrospector getClassIntrospector() {
        return _base.getClassIntrospector();
    }

    /**
     * Method for getting {@link AnnotationIntrospector} configured
     * to introspect annotation values used for configuration.
     *<p>
     * Non-final since it is actually overridden by sub-classes (for now?)
     */
    public AnnotationIntrospector getAnnotationIntrospector() {
        if (isEnabled(MapperFeature.USE_ANNOTATIONS)) {
            return _base.getAnnotationIntrospector();
        }
        return NopAnnotationIntrospector.instance;
    }

    public final PropertyNamingStrategy getPropertyNamingStrategy() {
        return _base.getPropertyNamingStrategy();
    }

    // @since 2.12
    public final AccessorNamingStrategy.Provider getAccessorNaming() {
        return _base.getAccessorNaming();
    }

    public final HandlerInstantiator getHandlerInstantiator() {
        return _base.getHandlerInstantiator();
    }

    /*
    /**********************************************************
    /* Configuration: type and subtype handling
    /**********************************************************
     */

    /**
     * Method called to locate a type info handler for types that do not have
     * one explicitly declared via annotations (or other configuration).
     * If such default handler is configured, it is returned; otherwise
     * null is returned.
     */
    public final TypeResolverBuilder<?> getDefaultTyper(JavaType baseType) {
        return _base.getTypeResolverBuilder();
    }
    
    public abstract SubtypeResolver getSubtypeResolver();

    /**
     * Simple accessor for default {@link PolymorphicTypeValidator} to use for
     * legacy Default Typing methods ({@code ObjectMapper.enableDefaultTyping()})
     * and annotation based enabling.
     *<p>
     * Since 2.11 will also check {@link MapperFeature#BLOCK_UNSAFE_POLYMORPHIC_BASE_TYPES}
     * to possibly override default to more restrictive implementation, see
     * {@link com.fasterxml.jackson.databind.jsontype.DefaultBaseTypeLimitingValidator}).
     *
     * @since 2.10
     */
    public PolymorphicTypeValidator getPolymorphicTypeValidator() {
        PolymorphicTypeValidator ptv = _base.getPolymorphicTypeValidator();
        // [databind#2587]: allow stricter default settings:
        if (ptv == LaissezFaireSubTypeValidator.instance) {
            if (isEnabled(MapperFeature.BLOCK_UNSAFE_POLYMORPHIC_BASE_TYPES)) {
                ptv = new DefaultBaseTypeLimitingValidator();
            }
        }
        return ptv;
    }

    public final TypeFactory getTypeFactory() {
        return _base.getTypeFactory();
    }

    /**
     * Helper method that will construct {@link JavaType} for given
     * raw class.
     * This is a simple short-cut for:
     *<pre>
     *    getTypeFactory().constructType(cls);
     *</pre>
     */
    public final JavaType constructType(Class<?> cls) {
        return getTypeFactory().constructType(cls);
    }

    /**
     * Helper method that will construct {@link JavaType} for given
     * type reference
     * This is a simple short-cut for:
     *<pre>
     *    getTypeFactory().constructType(valueTypeRef);
     *</pre>
     */
    public final JavaType constructType(TypeReference<?> valueTypeRef) {
        return getTypeFactory().constructType(valueTypeRef.getType());
    }

    public JavaType constructSpecializedType(JavaType baseType, Class<?> subclass) {
        // note: since 2.11 specify "strict" resolution
        return getTypeFactory().constructSpecializedType(baseType, subclass, true);
    }

    /*
    /**********************************************************
    /* Configuration: introspection support
    /**********************************************************
     */

    /**
     * Accessor for getting bean description that only contains class
     * annotations: useful if no getter/setter/creator information is needed.
     */
    public BeanDescription introspectClassAnnotations(Class<?> cls) {
        return introspectClassAnnotations(constructType(cls));
    }

    /**
     * Accessor for getting bean description that only contains class
     * annotations: useful if no getter/setter/creator information is needed.
     */
    public BeanDescription introspectClassAnnotations(JavaType type) {
        return getClassIntrospector().forClassAnnotations(this, type, this);
    }

    /**
     * Accessor for getting bean description that only contains immediate class
     * annotations: ones from the class, and its direct mix-in, if any, but
     * not from super types.
     */
    public BeanDescription introspectDirectClassAnnotations(Class<?> cls) {
        return introspectDirectClassAnnotations(constructType(cls));
    }

    /**
     * Accessor for getting bean description that only contains immediate class
     * annotations: ones from the class, and its direct mix-in, if any, but
     * not from super types.
     */
    public final BeanDescription introspectDirectClassAnnotations(JavaType type) {
        return getClassIntrospector().forDirectClassAnnotations(this, type, this);
    }

    /*
    /**********************************************************
    /* Configuration: default settings with per-type overrides
    /**********************************************************
     */

    /**
     * Accessor for finding {@link ConfigOverride} to use for
     * properties of given type, if any exist; or return `null` if not.
     *<p>
     * Note that only directly associated override
     * is found; no type hierarchy traversal is performed.
     *
     * @since 2.8
     * 
     * @return Override object to use for the type, if defined; null if none.
     */
    public abstract ConfigOverride findConfigOverride(Class<?> type);

    /**
     * Accessor for finding {@link ConfigOverride} to use for
     * properties of given type, if any exist; or if none, return an immutable
     * "empty" instance with no overrides.
     *<p>
     * Note that only directly associated override
     * is found; no type hierarchy traversal is performed.
     *
     * @since 2.9
     * 
     * @return Override object to use for the type, never null (but may be empty)
     */
    public abstract ConfigOverride getConfigOverride(Class<?> type);

    /**
     * Accessor for default property inclusion to use for serialization,
     * used unless overridden by per-type or per-property overrides.
     *
     * @since 2.7
     */
    public abstract JsonInclude.Value getDefaultPropertyInclusion();

    /**
     * Accessor for default property inclusion to use for serialization,
     * considering possible per-type override for given base type.<br>
     * NOTE: if no override found, defaults to value returned by
     * {@link #getDefaultPropertyInclusion()}.
     *
     * @since 2.7
     */
    public abstract JsonInclude.Value getDefaultPropertyInclusion(Class<?> baseType);

    /**
     * Accessor for default property inclusion to use for serialization,
     * considering possible per-type override for given base type; but
     * if none found, returning given <code>defaultIncl</code>
     *
     * @param defaultIncl Inclusion setting to return if no overrides found.
     * 
     * @since 2.8.2
     */
    public JsonInclude.Value getDefaultPropertyInclusion(Class<?> baseType,
            JsonInclude.Value defaultIncl)
    {
        JsonInclude.Value v = getConfigOverride(baseType).getInclude();
        if (v != null) {
            return v;
        }
        return defaultIncl;
    }

    /**
     * Accessor for default property inclusion to use for serialization,
     * considering possible per-type override for given base type and
     * possible per-type override for given property type.<br>
     * NOTE: if no override found, defaults to value returned by
     * {@link #getDefaultPropertyInclusion()}.
     *
     * @param baseType Type of the instance containing the targeted property.
     * @param propertyType Type of the property to look up inclusion setting for.
     *
     * @since 2.9
     */
    public abstract JsonInclude.Value getDefaultInclusion(Class<?> baseType,
            Class<?> propertyType);

    /**
     * Accessor for default property inclusion to use for serialization,
     * considering possible per-type override for given base type and
     * possible per-type override for given property type; but
     * if none found, returning given <code>defaultIncl</code>
     *
     * @param baseType Type of the instance containing the targeted property.
     * @param propertyType Type of the property to look up inclusion setting for.
     * @param defaultIncl Inclusion setting to return if no overrides found.
     *
     * @since 2.9
     */
    public JsonInclude.Value getDefaultInclusion(Class<?> baseType,
            Class<?> propertyType, JsonInclude.Value defaultIncl)
    {
        JsonInclude.Value baseOverride = getConfigOverride(baseType).getInclude();
        JsonInclude.Value propOverride = getConfigOverride(propertyType).getIncludeAsProperty();

        JsonInclude.Value result = JsonInclude.Value.mergeAll(defaultIncl, baseOverride, propOverride);
        return result;
    }

    /**
     * Accessor for default format settings to use for serialization (and, to a degree
     * deserialization), considering baseline settings and per-type defaults
     * for given base type (if any).
     *
     * @since 2.7
     */
    public abstract JsonFormat.Value getDefaultPropertyFormat(Class<?> baseType);

    /**
     * Accessor for default property ignorals to use, if any, for given base type,
     * based on config overrides settings (see {@link #findConfigOverride(Class)}).
     *
     * @since 2.8
     */
    public abstract JsonIgnoreProperties.Value getDefaultPropertyIgnorals(Class<?> baseType);

    /**
     * Helper method that may be called to see if there are property ignoral
     * definitions from annotations (via {@link AnnotatedClass}) or through
     * "config overrides". If both exist, config overrides have precedence
     * over class annotations.
     *
     * @since 2.8
     */
    public abstract JsonIgnoreProperties.Value getDefaultPropertyIgnorals(Class<?> baseType,
            AnnotatedClass actualClass);

    /**
     * Helper method that may be called to see if there are property inclusion
     * definitions from annotations (via {@link AnnotatedClass}).
     *
     * TODO: config override.
     *
     * @since 2.12
     */
    public abstract JsonIncludeProperties.Value getDefaultPropertyInclusions(Class<?> baseType,
            AnnotatedClass actualClass);

    /**
     * Accessor for object used for determining whether specific property elements
     * (method, constructors, fields) can be auto-detected based on
     * their visibility (access modifiers). Can be changed to allow
     * different minimum visibility levels for auto-detection. Note
     * that this is the global handler; individual types (classes)
     * can further override active checker used (using
     * {@link JsonAutoDetect} annotation)
     */
    public abstract VisibilityChecker<?> getDefaultVisibilityChecker();

    /**
     * Accessor for object used for determining whether specific property elements
     * (method, constructors, fields) can be auto-detected based on
     * their visibility (access modifiers). This is based on global defaults
     * (as would be returned by {@link #getDefaultVisibilityChecker()}, but
     * then modified by possible class annotation (see {@link JsonAutoDetect})
     * and/or per-type config override (see {@link ConfigOverride#getVisibility()}).
     *
     * @since 2.9
     */
    public abstract VisibilityChecker<?> getDefaultVisibilityChecker(Class<?> baseType,
            AnnotatedClass actualClass);

    /**
     * Accessor for the baseline setter info used as the global baseline,
     * not considering possible per-type overrides.
     *
     * @return Global base settings; never null
     *
     * @since 2.9
     */
    public abstract JsonSetter.Value getDefaultSetterInfo();

    /**
     * Accessor for the baseline merge info used as the global baseline,
     * not considering possible per-type overrides.
     *
     * @return Global base settings, if any; `null` if none.
     *
     * @since 2.9
     */
    public abstract Boolean getDefaultMergeable();

    /**
     * Accessor for the baseline merge info used for given type, including global
     * defaults if no type-specific overrides defined.
     *
     * @return Type-specific settings (if any); global defaults (same as
     *    {@link #getDefaultMergeable()}) otherwise, if any defined; or `null`
     *    if neither defined
     *
     * @since 2.9
     */
    public abstract Boolean getDefaultMergeable(Class<?> baseType);

    /*
    /**********************************************************
    /* Configuration: other
    /**********************************************************
     */
    
    /**
     * Method for accessing currently configured (textual) date format
     * that will be used for reading or writing date values (in case
     * of writing, only if textual output is configured; not if dates
     * are to be serialized as time stamps).
     *<p>
     * Note that typically {@link DateFormat} instances are <b>not thread-safe</b>
     * (at least ones provided by JDK):
     * this means that calling code should clone format instance before
     * using it.
     *<p>
     * This method is usually only called by framework itself, since there
     * are convenience methods available via
     * {@link DeserializationContext} and {@link SerializerProvider} that
     * take care of cloning and thread-safe reuse.
     */
    public final DateFormat getDateFormat() { return _base.getDateFormat(); }

    /**
     * Method for accessing the default {@link java.util.Locale} to use
     * for formatting, unless overridden by local annotations.
     * Initially set to {@link Locale#getDefault()}.
     */
    public final Locale getLocale() { return _base.getLocale(); }

    /**
     * Method for accessing the default {@link java.util.TimeZone} to use
     * for formatting, unless overridden by local annotations.
     * Initially set to {@link TimeZone#getDefault()}.
     */
    public final TimeZone getTimeZone() { return _base.getTimeZone(); }

    /**
     * Method for checking whether a {@link java.util.TimeZone} has been explicitly
     * set for this configuring during construction of {@code ObjectMapper}
     * or if it still has the default timezone/offset (zero-offset, "zulu").
     *
     * @return {@code true} if this configuration has explicitly specified
     *    {@link java.util.TimeZone}, or {@code false} if it uses the default
     *    time zone
     *
     * @since 2.12
     */
    public boolean hasExplicitTimeZone() {
        return _base.hasExplicitTimeZone();
    }

    /**
     * Accessor for finding currently active view, if any (null if none)
     */
    public abstract Class<?> getActiveView();

    /**
     * Method called during deserialization if Base64 encoded content
     * needs to be decoded. Default version just returns default Jackson
     * uses, which is modified-mime which does not add linefeeds (because
     * those would have to be escaped in JSON strings); but this can
     * be configured on {@link ObjectWriter}.
     */
    public Base64Variant getBase64Variant() {
        return _base.getBase64Variant();
    }

    /**
     * Method for accessing per-instance shared (baseline/default)
     * attribute values; these are used as the basis for per-call
     * attributes.
     * 
     * @since 2.3
     */
    public abstract ContextAttributes getAttributes();

    /**
     * @since 2.6
     */
    public abstract PropertyName findRootName(JavaType rootType);

    /**
     * @since 2.6
     */
    public abstract PropertyName findRootName(Class<?> rawRootType);

    /*
    /**********************************************************
    /* Methods for instantiating handlers
    /**********************************************************
     */

    /**
     * Method that can be called to obtain an instance of <code>TypeIdResolver</code> of
     * specified type.
     */
    public TypeResolverBuilder<?> typeResolverBuilderInstance(Annotated annotated,
            Class<? extends TypeResolverBuilder<?>> builderClass)
    {
        HandlerInstantiator hi = getHandlerInstantiator();
        if (hi != null) {
            TypeResolverBuilder<?> builder = hi.typeResolverBuilderInstance(this, annotated, builderClass);
            if (builder != null) {
                return builder;
            }
        }
        return (TypeResolverBuilder<?>) ClassUtil.createInstance(builderClass, canOverrideAccessModifiers());
    }

    /**
     * Method that can be called to obtain an instance of <code>TypeIdResolver</code> of
     * specified type.
     */
    public TypeIdResolver typeIdResolverInstance(Annotated annotated,
            Class<? extends TypeIdResolver> resolverClass)
    {
        HandlerInstantiator hi = getHandlerInstantiator();
        if (hi != null) {
            TypeIdResolver builder = hi.typeIdResolverInstance(this, annotated, resolverClass);
            if (builder != null) {
                return builder;
            }
        }
        return (TypeIdResolver) ClassUtil.createInstance(resolverClass, canOverrideAccessModifiers());
    }
}

⏎ com/fasterxml/jackson/databind/cfg/MapperConfig.java

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