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

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

You can also browse Jackson Core Source Code below:

⏎ com/fasterxml/jackson/core/type/ResolvedType.java

package com.fasterxml.jackson.core.type;

/**
 * Type abstraction that represents Java type that has been resolved
 * (i.e. has all generic information, if any, resolved to concrete
 * types).
 * Note that this is an intermediate type, and all concrete instances
 * MUST be of type <code>JavaType</code> from "databind" bundle -- this
 * abstraction is only needed so that types can be passed through
 * {@link com.fasterxml.jackson.core.JsonParser#readValueAs} methods.
 * 
 * @since 2.0
 */
public abstract class ResolvedType
{
    /*
    /**********************************************************
    /* Public API, simple property accessors
    /**********************************************************
     */

    /**
     * @return Type-erased {@link Class} of resolved type
     */
    public abstract Class<?> getRawClass();

    public abstract boolean hasRawClass(Class<?> clz);

    public abstract boolean isAbstract();
    
    public abstract boolean isConcrete();

    public abstract boolean isThrowable();

    public abstract boolean isArrayType();

    public abstract boolean isEnumType();

    public abstract boolean isInterface();

    public abstract boolean isPrimitive();

    public abstract boolean isFinal();

    public abstract boolean isContainerType();

    public abstract boolean isCollectionLikeType();

    /**
     * Whether this type is a referential type, meaning that values are
     * basically pointers to "real" values (or null) and not regular
     * values themselves. Typical examples include things like
     * {@link java.util.concurrent.atomic.AtomicReference}, and various
     * <code>Optional</code> types (in JDK8, Guava).
     *
     * @return {@code True} if this is a "referential" type, {@code false} if not
     *
     * @since 2.6
     */
    public boolean isReferenceType() {
        return getReferencedType() != null;
    }

    public abstract boolean isMapLikeType();

    /*
    /**********************************************************
    /* Public API, type parameter access
    /**********************************************************
     */
    
    /**
     * Method that can be used to find out if the type directly declares generic
     * parameters (for its direct super-class and/or super-interfaces).
     *
     * @return {@code True} if this type has generic type parameters, {@code false} if not
     */
    public abstract boolean hasGenericTypes();

    /**
     * @deprecated Since 2.7: does not have meaning as parameters depend on type
     *    resolved.
     *
     * @return Type-erased class of something not usable at this point
     */
    @Deprecated // since 2.7
    public Class<?> getParameterSource() {
        return null;
    }

    /**
     * Method for accessing key type for this type, assuming type
     * has such a concept (only Map types do)
     *
     * @return Key type of this type, if any; {@code null} if none
     */
    public abstract ResolvedType getKeyType();

    /**
     * Method for accessing content type of this type, if type has
     * such a thing: simple types do not, structured types do
     * (like arrays, Collections and Maps)
     *
     * @return Content type of this type, if any; {@code null} if none
     */
    public abstract ResolvedType getContentType();

    /**
     * Method for accessing type of value that instances of this
     * type references, if any.
     * 
     * @return Referenced type, if any; {@code null} if not.
     * 
     * @since 2.6
     */
    public abstract ResolvedType getReferencedType();
    
    /**
     * Method for checking how many contained types this type
     * has. Contained types are usually generic types, so that
     * generic Maps have 2 contained types.
     *
     * @return Number of contained types that may be accessed
     */
    public abstract int containedTypeCount();

    /**
     * Method for accessing definitions of contained ("child")
     * types.
     * 
     * @param index Index of contained type to return
     * 
     * @return Contained type at index, or null if no such type
     *    exists (no exception thrown)
     */
    public abstract ResolvedType containedType(int index);
    
    /**
     * Method for accessing name of type variable in indicated
     * position. If no name is bound, will use placeholders (derived
     * from 0-based index); if no type variable or argument exists
     * with given index, null is returned.
     * 
     * @param index Index of contained type to return
     * 
     * @return Contained type at index, or null if no such type
     *    exists (no exception thrown)
     */
    public abstract String containedTypeName(int index);

    /*
    /**********************************************************
    /* Public API, other
    /**********************************************************
     */

    /**
     * Method that can be used to serialize type into form from which
     * it can be fully deserialized from at a later point (using
     * {@code TypeFactory} from mapper package).
     * For simple types this is same as calling
     * {@link Class#getName}, but for structured types it may additionally
     * contain type information about contents.
     *
     * @return String representation of the fully resolved type
     */
    public abstract String toCanonical();
}

⏎ com/fasterxml/jackson/core/type/ResolvedType.java

Or download all of them as a single archive file:

File name: jackson-core-2.14.0-sources.jar
File size: 497693 bytes
Release date: 2022-11-05
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