com.github.fge.jackson.jsonpointer
Class TreePointer<T extends com.fasterxml.jackson.core.TreeNode>

java.lang.Object
  com.github.fge.jackson.jsonpointer.TreePointer<T>

Type Parameters:

T - the type of the tree

All Implemented Interfaces:

Iterable<TokenResolver<T>>

Direct Known Subclasses:

JsonPointer

@ThreadSafe
public abstract class TreePointer<T extends com.fasterxml.jackson.core.TreeNode>
extends Object
implements Iterable<TokenResolver<T>>

A pointer into a TreeNode

Note that all pointers are absolute: they start from the root of the tree. This is to mirror the behaviour of JSON Pointer proper.

The class does not decode a JSON Pointer representation itself; however it provides all the necessary methods for implementations to achieve this.

This class has two traversal methods: get(TreeNode) and path(TreeNode). The difference between both is that path() may return another node than null if the tree representation has such a node. This is the case, for instance, for JsonNode, which has a MissingNode.

At the core, this class is essentially a(n ordered!) List of TokenResolvers (which is iterable via the class itself).

Note that this class' hashCode(), equals(Object) and toString() are final.

Field Summary

protected static MessageBundle	BUNDLE
protected List<TokenResolver<T>>	tokenResolvers The list of token resolvers

Constructor Summary

protected	TreePointer(List<TokenResolver<T>> tokenResolvers) Alternate constructor
protected	TreePointer(T missing, List<TokenResolver<T>> tokenResolvers) Main protected constructor

Method Summary

boolean	equals(Object obj)
T	get(T node) Traverse a node and return the result
int	hashCode()
boolean	isEmpty() Tell whether this pointer is empty
Iterator<TokenResolver<T>>	iterator()
T	path(T node) Traverse a node and return the result
protected static List<ReferenceToken>	tokensFromInput(String input) Decode an input into a list of reference tokens
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

BUNDLE

protected static final MessageBundle BUNDLE

tokenResolvers

protected final List<TokenResolver<T extends com.fasterxml.jackson.core.TreeNode>> tokenResolvers

The list of token resolvers

Constructor Detail

TreePointer

protected TreePointer(T missing,
                      List<TokenResolver<T>> tokenResolvers)

Main protected constructor

This constructor makes an immutable copy of the list it receives as an argument.

Parameters:

missing - the representation of a missing node (may be null)

tokenResolvers - the list of reference token resolvers

TreePointer

protected TreePointer(List<TokenResolver<T>> tokenResolvers)

Alternate constructor

This is the same as calling TreePointer(TreeNode, List) with null as the missing node.

Parameters:

tokenResolvers - the list of token resolvers

Method Detail

get

public final T get(T node)

Traverse a node and return the result

Note that this method shortcuts: it stops at the first node it cannot traverse.

Parameters:

node - the node to traverse

Returns:

the resulting node, null if not found

path

public final T path(T node)

Traverse a node and return the result

This is like get(TreeNode), but it will return the missing node if traversal fails.

Parameters:

node - the node to traverse

Returns:

the result, or the missing node

See Also:

TreePointer(TreeNode, List)

isEmpty

public final boolean isEmpty()

Tell whether this pointer is empty

Returns:

true if the reference token list is empty

iterator

public final Iterator<TokenResolver<T>> iterator()

Specified by:

iterator in interface Iterable<TokenResolver<T extends com.fasterxml.jackson.core.TreeNode>>

hashCode

public final int hashCode()

Overrides:

hashCode in class Object

equals

public final boolean equals(Object obj)

Overrides:

equals in class Object

toString

public final String toString()

Overrides:

toString in class Object

tokensFromInput

protected static List<ReferenceToken> tokensFromInput(String input)
                                               throws JsonPointerException

Decode an input into a list of reference tokens

Parameters:

input - the input

Returns:

the list of reference tokens

Throws:

JsonPointerException - input is not a valid JSON Pointer

NullPointerException - input is null