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/BeanDescription.java

package com.fasterxml.jackson.databind;

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.annotation.JsonPOJOBuilder;
import com.fasterxml.jackson.databind.introspect.*;
import com.fasterxml.jackson.databind.type.TypeBindings;
import com.fasterxml.jackson.databind.util.Annotations;
import com.fasterxml.jackson.databind.util.Converter;

/**
 * Basic container for information gathered by {@link ClassIntrospector} to
 * help in constructing serializers and deserializers.
 * Note that the main implementation type is
 * {@link com.fasterxml.jackson.databind.introspect.BasicBeanDescription},
 * meaning that it is safe to upcast to this type.
 */
public abstract class BeanDescription
{
    /**
     * Bean type information, including raw class and possible
     * generics information
     */
    protected final JavaType _type;

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

    protected BeanDescription(JavaType type) {
        _type = type;
    }

    /*
    /**********************************************************
    /* Simple accesors
    /**********************************************************
     */

    /**
     * Method for accessing declared type of bean being introspected,
     * including full generic type information (from declaration)
     */
    public JavaType getType() { return _type; }

    public Class<?> getBeanClass() { return _type.getRawClass(); }

    /**
     * @since 2.9
     */
    public boolean isNonStaticInnerClass() {
        return getClassInfo().isNonStaticInnerClass();
    }

    /**
     * Method for accessing low-level information about Class this
     * item describes.
     */
    public abstract AnnotatedClass getClassInfo();

    /**
     * Accessor for getting information about Object Id expected to
     * be used for this POJO type, if any.
     */
    public abstract ObjectIdInfo getObjectIdInfo();
    
    /**
     * Method for checking whether class being described has any
     * annotations recognized by registered annotation introspector.
     */
    public abstract boolean hasKnownClassAnnotations();

    /**
     * Accessor for type bindings that may be needed to fully resolve
     * types of member object, such as return and argument types of
     * methods and constructors, and types of fields.
     *
     * @deprecated Since 2.7, should not need to access bindings directly
     */
    @Deprecated
    public abstract TypeBindings bindingsForBeanType();

    /**
     * Method for resolving given JDK type, using this bean as the
     * generic type resolution context.
     *
     * @deprecated Since 2.8, should simply call <code>getType</code> of
     *    property accessor directly.
     */
    @Deprecated
    public abstract JavaType resolveType(java.lang.reflect.Type jdkType);

    /**
     * Method for accessing collection of annotations the bean
     * class has.
     */
    public abstract Annotations getClassAnnotations();

    /*
    /**********************************************************
    /* Basic API for finding properties
    /**********************************************************
     */

    /**
     * @return Ordered Map with logical property name as key, and
     *    matching getter method as value.
     */
    public abstract List<BeanPropertyDefinition> findProperties();

    public abstract Set<String> getIgnoredPropertyNames();

    /**
     * Method for locating all back-reference properties (setters, fields) bean has
     *
     * @since 2.9
     */
    public abstract List<BeanPropertyDefinition> findBackReferences();

    /**
     * Method for locating all back-reference properties (setters, fields) bean has
     *
     * @deprecated Since 2.9 use {@link #findBackReferences()} instead
     */
    @Deprecated
    public abstract Map<String,AnnotatedMember> findBackReferenceProperties();

    /*
    /**********************************************************
    /* Basic API for finding creator members
    /**********************************************************
     */

    /**
     * Helper method that will return all non-default constructors (that is,
     * constructors that take one or more arguments) this class has.
     */
    public abstract List<AnnotatedConstructor> getConstructors();

    /**
     * Method similar to {@link #getConstructors()} except will also introspect
     * {@code JsonCreator.Mode} and filter out ones marked as not applicable and
     * include mode (or lack thereof) for remaining constructors.
     *<p>
     * Note that no other filtering (regarding visibility or other annotations)
     * is performed
     *
     * @since 2.13
     */
    public abstract List<AnnotatedAndMetadata<AnnotatedConstructor, JsonCreator.Mode>> getConstructorsWithMode();

    /**
     * Helper method that will check all static methods of the bean class
     * that seem like factory methods eligible to be used as Creators.
     * This requires that the static method:
     *<ol>
     * <li>Returns type compatible with bean type (same or subtype)
     *  </li>
     * <li>Is recognized from either explicit annotation (usually {@code @JsonCreator}
     *   OR naming:
     *   names {@code valueOf()} and {@code fromString()} are recognized but
     *   only for 1-argument factory methods, and in case of {@code fromString()}
     *   argument type must further be either {@code String} or {@code CharSequence}.
     *  </li>
     *</ol>
     * Note that caller typically applies further checks for things like visibility.
     *
     * @return List of static methods considered as possible Factory methods
     */
    public abstract List<AnnotatedMethod> getFactoryMethods();

    /**
     * Method similar to {@link #getFactoryMethods()} but will return {@code JsonCreator.Mode}
     * metadata along with qualifying factory method candidates.
     *
     * @since 2.13
     */
    public abstract List<AnnotatedAndMetadata<AnnotatedMethod, JsonCreator.Mode>> getFactoryMethodsWithMode();

    /**
     * Method that will locate the no-arg constructor for this class,
     * if it has one, and that constructor has not been marked as
     * ignorable.
     */
    public abstract AnnotatedConstructor findDefaultConstructor();

    /**
     * @deprecated Since 2.13: instead use {@link #getConstructors()}, filter.
     */
    @Deprecated
    public abstract Constructor<?> findSingleArgConstructor(Class<?>... argTypes);

    /**
     * @deprecated Since 2.13: instead use {@link #getFactoryMethods()}, filter.
     */
    @Deprecated
    public abstract Method findFactoryMethod(Class<?>... expArgTypes);

    /*
    /**********************************************************
    /* Basic API for finding property accessors
    /**********************************************************
     */

    /**
     * Method for locating accessor (readable field, or "getter" method)
     * that has
     * {@link com.fasterxml.jackson.annotation.JsonKey} annotation,
     * if any. If multiple ones are found,
     * an error is reported by throwing {@link IllegalArgumentException}
     *
     * @since 2.12
     */
    public AnnotatedMember findJsonKeyAccessor() {
        return null;
    }

    /**
     * Method for locating accessor (readable field, or "getter" method)
     * that has
     * {@link com.fasterxml.jackson.annotation.JsonValue} annotation,
     * if any. If multiple ones are found,
     * an error is reported by throwing {@link IllegalArgumentException}
     *
     * @since 2.9
     */
    public abstract AnnotatedMember findJsonValueAccessor();

    public abstract AnnotatedMember findAnyGetter();

    /**
     * Method used to locate a mutator (settable field, or 2-argument set method)
     * of introspected class that
     * implements {@link com.fasterxml.jackson.annotation.JsonAnySetter}.
     * If no such mutator exists null is returned. If more than one are found,
     * an exception is thrown.
     * Additional checks are also made to see that method signature
     * is acceptable: needs to take 2 arguments, first one String or
     * Object; second any can be any type.
     *
     * @since 2.9
     */
    public abstract AnnotatedMember findAnySetterAccessor();

    public abstract AnnotatedMethod findMethod(String name, Class<?>[] paramTypes);

    @Deprecated // since 2.9
    public abstract AnnotatedMethod findJsonValueMethod();
    
    /**
     * @deprecated Since 2.9: use {@link #findAnySetterAccessor} instead
     */
    @Deprecated
    public AnnotatedMethod findAnySetter() {
        AnnotatedMember m = findAnySetterAccessor();
        if (m instanceof AnnotatedMethod) {
            return (AnnotatedMethod) m;
        }
        return null;
    }

    /**
     * @deprecated Since 2.9: use {@link #findAnySetterAccessor} instead
     */
    @Deprecated
    public AnnotatedMember findAnySetterField() {
        AnnotatedMember m = findAnySetterAccessor();
        if (m instanceof AnnotatedField) {
            return m;
        }
        return null;
    }

    /*
    /**********************************************************
    /* Basic API, class configuration
    /**********************************************************
     */

    /**
     * Method for finding annotation-indicated inclusion definition (if any);
     * possibly overriding given default value.
     *<p>
     * NOTE: does NOT use global inclusion default settings as the base, unless
     * passed as `defValue`.
     *
     * @since 2.7
     */
    public abstract JsonInclude.Value findPropertyInclusion(JsonInclude.Value defValue);

    /**
     * Method for checking what is the expected format for POJO, as
     * defined by defaults and possible annotations.
     * Note that this may be further refined by per-property annotations.
     * 
     * @since 2.1
     */
    public abstract JsonFormat.Value findExpectedFormat(JsonFormat.Value defValue);

    /**
     * Method for finding {@link Converter} used for serializing instances
     * of this class.
     * 
     * @since 2.2
     */
    public abstract Converter<Object,Object> findSerializationConverter();

    /**
     * Method for finding {@link Converter} used for serializing instances
     * of this class.
     * 
     * @since 2.2
     */
    public abstract Converter<Object,Object> findDeserializationConverter();

    /**
     * Accessor for possible description for the bean type, used for constructing
     * documentation.
     *
     * @since 2.7
     */
    public String findClassDescription() { return null; }

    /*
    /**********************************************************
    /* Basic API, other
    /**********************************************************
     */

    public abstract Map<Object, AnnotatedMember> findInjectables();

    /**
     * Method for checking if the POJO type has annotations to
     * indicate that a builder is to be used for instantiating
     * instances and handling data binding, instead of standard
     * bean deserializer.
     */
    public abstract Class<?> findPOJOBuilder();

    /**
     * Method for finding configuration for POJO Builder class.
     */
    public abstract JsonPOJOBuilder.Value findPOJOBuilderConfig();

    /**
     * Method called to create a "default instance" of the bean, currently
     * only needed for obtaining default field values which may be used for
     * suppressing serialization of fields that have "not changed".
     * 
     * @param fixAccess If true, method is allowed to fix access to the
     *   default constructor (to be able to call non-public constructor);
     *   if false, has to use constructor as is.
     *
     * @return Instance of class represented by this descriptor, if
     *   suitable default constructor was found; null otherwise.
     */
    public abstract Object instantiateBean(boolean fixAccess);

    /**
     * Method for finding out if the POJO specifies default view(s) to
     * use for properties, considering both per-type annotations and
     * global default settings.
     *
     * @since 2.9
     */
    public abstract Class<?>[] findDefaultViews();
}

⏎ com/fasterxml/jackson/databind/BeanDescription.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
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