Module org.microbean.loader.jackson

Package org.microbean.loader.jackson

Class JacksonProvider

java.lang.Object

org.microbean.loader.spi.AbstractProvider

org.microbean.loader.spi.AbstractTreeBasedProvider<TreeNode>

org.microbean.loader.jackson.JacksonProvider

All Implemented Interfaces:

Provider

Direct Known Subclasses:

InputStreamJacksonProvider

public abstract class JacksonProvider
extends AbstractTreeBasedProvider<TreeNode>

A partial AbstractTreeBasedProvider implementation backed by Jackson.

Author:

Laird Nelson

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	JacksonProvider()	Creates a new JacksonProvider.
protected	JacksonProvider(Type lowerBound)	Creates a new JacksonProvider.

Method Summary

Modifier and Type	Method	Description
final boolean	absent(TreeNode node)	Returns true if the supplied node is null, absent or synthetic.
final TreeNode	get(TreeNode node, int index)	Returns the child node of the supplied parent node identified by the supplied index, or null if either the child does not exist or node is not a list node.
final TreeNode	get(TreeNode node, String name)	Returns the child node of the supplied parent node identified by the supplied name, or null if either the child does not exist or node is not a map node.
final boolean	list(TreeNode node)	Returns true if the supplied node represents a list or an array, and therefore the AbstractTreeBasedProvider.get(Object, int) method is likely to be relevant.
final boolean	map(TreeNode node)	Returns true if the supplied node represents a map, and therefore the AbstractTreeBasedProvider.get(Object, String) method is likely to be relevant.
final Iterator<String>	names(TreeNode node)	Returns an Iterator over the names of the supplied node's child nodes, or an empty Iterator if the supplied node is not a map node.
final boolean	nil(TreeNode node)	Returns true if the supplied node is null or represents an explicitly set null value.
protected abstract ObjectCodec	objectCodec(Loader<?> requestor, Path<? extends Type> absolutePath)	Returns an ObjectCodec suitable for the combination of the supplied Loader and Path, or null if there is no such ObjectCodec.
protected TreeNode	qualifiers(TreeNode node)	Returns a node possibly containing qualifiers applicable to the supplied node, or null.
protected BiFunction<? super TreeNode,? super Type,?>	reader(Loader<?> requestor, Path<? extends Type> absolutePath)	Returns a BiFunction accepting a node and a Type and returning the result of reading an object of that type, or null if no such BiFunction could be sourced.
final int	size(TreeNode node)	Returns the number of child nodes the supplied node has, which may be (and often is) 0.

Methods inherited from class org.microbean.loader.spi.AbstractTreeBasedProvider

container, find, path, path, qualifiers, rootNode

Methods inherited from class org.microbean.loader.spi.AbstractProvider

get, lowerBound

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

JacksonProvider

protected JacksonProvider()

Creates a new JacksonProvider.

See Also:

• JacksonProvider(Type)

JacksonProvider

protected JacksonProvider(Type lowerBound)

Creates a new JacksonProvider.

Parameters:

lowerBound - the lower type bound of this JacksonProvider implementation; may be null

Method Details

size

public final int size(TreeNode node)

Description copied from class: AbstractTreeBasedProvider

Returns the number of child nodes the supplied node has, which may be (and often is) 0.

If the supplied null is null, absent or a scalar, an override of this method must return 0.

Specified by:

size in class AbstractTreeBasedProvider<TreeNode>

Parameters:

node - the parent node; may be null in which case 0 must be returned

Returns:

the number of child nodes the supplied node has, which may be (and often is) 0

names

public final Iterator<String> names(TreeNode node)

Description copied from class: AbstractTreeBasedProvider

Returns an Iterator over the names of the supplied node's child nodes, or an empty Iterator if the supplied node is not a map node.

Specified by:

names in class AbstractTreeBasedProvider<TreeNode>

Parameters:

node - the parent node; may be null in which case an empty Iterator must be returned

Returns:

an Iterator; never null

get

public final TreeNode get(TreeNode node,
 String name)

Description copied from class: AbstractTreeBasedProvider

Returns the child node of the supplied parent node identified by the supplied name, or null if either the child does not exist or node is not a map node.

Specified by:

get in class AbstractTreeBasedProvider<TreeNode>

Parameters:

node - the parent node; may be null in which case null must be returned

name - the name of the child; must not be null

Returns:

the child node of the supplied parent node identified by the supplied name, or null if either the child does not exist or node is not a map node

get

public final TreeNode get(TreeNode node,
 int index)

Description copied from class: AbstractTreeBasedProvider

Returns the child node of the supplied parent node identified by the supplied index, or null if either the child does not exist or node is not a list node.

Specified by:

get in class AbstractTreeBasedProvider<TreeNode>

Parameters:

node - the parent node; may be null in which case null must be returned

index - the zero-based index of the child

Returns:

the child node of the supplied parent node identified by the supplied name, or null if either the child does not exist or node is not a map node

absent

public final boolean absent(TreeNode node)

Description copied from class: AbstractTreeBasedProvider

Returns true if the supplied node is null, absent or synthetic.

Specified by:

absent in class AbstractTreeBasedProvider<TreeNode>

Parameters:

node - the node to test; may be null in which case true must be returned

Returns:

true if the supplied node is null, absent or synthetic

nil

public final boolean nil(TreeNode node)

Description copied from class: AbstractTreeBasedProvider

Returns true if the supplied node is null or represents an explicitly set null value.

Specified by:

nil in class AbstractTreeBasedProvider<TreeNode>

Parameters:

node - the node to test; may be null in which case true must be returned

Returns:

true if the supplied node is null or represents an explicitly set null value

map

public final boolean map(TreeNode node)

Description copied from class: AbstractTreeBasedProvider

Returns true if the supplied node represents a map, and therefore the AbstractTreeBasedProvider.get(Object, String) method is likely to be relevant.

Specified by:

map in class AbstractTreeBasedProvider<TreeNode>

Parameters:

node - the node to test; may be null in which case false must be returned

Returns:

true if the supplied node represents a map, and therefore the AbstractTreeBasedProvider.get(Object, String) method is likely to be relevant

list

public final boolean list(TreeNode node)

Description copied from class: AbstractTreeBasedProvider

Returns true if the supplied node represents a list or an array, and therefore the AbstractTreeBasedProvider.get(Object, int) method is likely to be relevant.

Specified by:

list in class AbstractTreeBasedProvider<TreeNode>

Parameters:

node - the node to test; may be null in which case false must be returned

Returns:

true if the supplied node represents a list or an array, and therefore the AbstractTreeBasedProvider.get(Object, int) method is likely to be relevant

qualifiers

protected TreeNode qualifiers(TreeNode node)

Description copied from class: AbstractTreeBasedProvider

Returns a node possibly containing qualifiers applicable to the supplied node, or null.

Specified by:

qualifiers in class AbstractTreeBasedProvider<TreeNode>

Parameters:

node - the node for which a corresponding qualifiers node should be returned; may be null in which case null must be returned

Returns:

a node possibly containing qualifiers applicable to the supplied node, or null

objectCodec

protected abstract ObjectCodec objectCodec(Loader<?> requestor,
 Path<? extends Type> absolutePath)

Returns an ObjectCodec suitable for the combination of the supplied Loader and Path, or null if there is no such ObjectCodec.

This method is called by the AbstractProvider.get(Loader, Path) method in the normal course of events.

Parameters:

requestor - the Loader seeking a Value; must not be null

absolutePath - an absolute Path for which the supplied Loader is seeking a value; must not be null

Returns:

an ObjectCodec suitable for the combination of the supplied Loader and Path, or null

Idempotency:

Implementations of this method must be idempotent, but not necessarily deterministic.

Nullability:

Implementations of this method may return null.

Thread Safety:

Implementations of this method must be safe for concurrent use by multiple threads.

reader

protected BiFunction<? super TreeNode,? super Type,?> reader(Loader<?> requestor,
 Path<? extends Type> absolutePath)

Description copied from class: AbstractTreeBasedProvider

Returns a BiFunction accepting a node and a Type and returning the result of reading an object of that type, or null if no such BiFunction could be sourced.

Specified by:

reader in class AbstractTreeBasedProvider<TreeNode>

Parameters:

requestor - the Loader currently executing a request; must not be null

absolutePath - the path being requested; must not be null and must be absolute

Returns:

a BiFunction accepting a node and a Type and returning the result of reading an object of that type, or null if no such BiFunction could be sourced