Package org.apache.jackrabbit.oak.plugins.tree.impl

Class ImmutableTree

java.lang.Object
org.apache.jackrabbit.oak.plugins.tree.impl.AbstractTree
org.apache.jackrabbit.oak.plugins.tree.impl.ImmutableTree
All Implemented Interfaces:
Tree, ReadOnly, TreeTypeAware
public final class ImmutableTree extends AbstractTree implements TreeTypeAware, ReadOnly
Immutable implementation of the Tree interface in order to provide the much feature rich API functionality for a given NodeState.

Tree hierarchy

Due to the nature of this Tree implementation creating a proper hierarchical view of the tree structure is the responsibility of the caller. It is recommended to start with the state of the root node and build up the hierarchy by calling ImmutableTree(ImmutableTree, String, org.apache.jackrabbit.oak.spi.state.NodeState) for every subsequent child state. Note, that this implementation will not perform any kind of validation of the passed state and methods like isRoot(), getName() or getPath() will just make use of the hierarchy that has been create by that sequence. In order to create a disconnected individual tree in cases where the hierarchy information is not (yet) need or known it is suggested to use ImmutableTree(ImmutableTree.ParentProvider, String, org.apache.jackrabbit.oak.spi.state.NodeState) an specify an appropriate ParentProvider implementation.

ParentProvider

Apart from create the tree hierarchy in traversal mode this tree implementation allows to instantiate disconnected trees that depending on the use may never or on demand retrieve hierarchy information. The following default implementations of this internal interface are present:

Filtering 'hidden' items

This Tree implementation reflects the item hierarchy as exposed by the underlying NodeState. In contrast to the mutable implementations it does not filter out 'hidden' items as identified by org.apache.jackrabbit.oak.spi.state.NodeStateUtils#isHidden(String).

Equality and hash code

In contrast to AbstractMutableTree the ImmutableTree implements Object.equals(Object) and Object.hashCode(): Two ImmutableTrees are consider equal if their name and the underlying NodeStates are equal. Note however, that according to the contract defined in NodeState these objects are not expected to be used as hash keys.

  • Constructor Details

  • Method Details

    • getType

      @Nullable public @Nullable TreeType getType()
      Specified by:
      getType in interface TreeTypeAware

    • setType

      public void setType(@NotNull @NotNull TreeType type)
      Specified by:
      setType in interface TreeTypeAware

    • createChild

      @NotNull protected @NotNull ImmutableTree createChild(@NotNull @NotNull String name)
      Description copied from class: AbstractTree
      Factory method for creating child trees
      Specified by:
      createChild in class AbstractTree
      Parameters:
      name - name of the child tree
      Returns:
      child tree of this tree with the given name

    • isRoot

      public boolean isRoot()
      Specified by:
      isRoot in interface Tree
      Overrides:
      isRoot in class AbstractTree
      Returns:
      true iff this is the root

    • getParentOrNull

      @Nullable protected @Nullable AbstractTree getParentOrNull()
      Specified by:
      getParentOrNull in class AbstractTree
      Returns:
      the parent of this tree or null for the root

    • getNodeBuilder

      @NotNull protected @NotNull NodeBuilder getNodeBuilder()
      Specified by:
      getNodeBuilder in class AbstractTree
      Returns:
      The NodeBuilder for the underlying node state

    • isHidden

      protected boolean isHidden(@NotNull @NotNull String name)
      Description copied from class: AbstractTree
      Determine whether an item should be hidden. I.e. not exposed through this tree.
      Overrides:
      isHidden in class AbstractTree
      Parameters:
      name - name of an item
      Returns:
      true if the item is hidden, false otherwise.

    • getInternalNodeNames

      @NotNull protected @NotNull String[] getInternalNodeNames()
      Overrides:
      getInternalNodeNames in class AbstractTree

    • getName

      @NotNull public @NotNull String getName()
      Specified by:
      getName in interface Tree
      Returns:
      the name of this Tree instance.

    • getPath

      @NotNull public @NotNull String getPath()
      Specified by:
      getPath in interface Tree
      Overrides:
      getPath in class AbstractTree
      Returns:
      the absolute path of this Tree instance from its Root.

    • getChild

      @NotNull public @NotNull ImmutableTree getChild(@NotNull @NotNull String name) throws IllegalArgumentException
      Description copied from interface: Tree
      Get a possibly non existing child of this Tree.
      Specified by:
      getChild in interface Tree
      Overrides:
      getChild in class AbstractTree
      Parameters:
      name - The name of the child to retrieve.
      Returns:
      The child with the given name.
      Throws:
      IllegalArgumentException - if the given name is invalid

    • remove

      public boolean remove()
      Description copied from interface: Tree
      Remove this tree instance. This operation never succeeds for the root tree.
      Specified by:
      remove in interface Tree
      Returns:
      true if the node was removed; false otherwise.

    • addChild

      @NotNull public @NotNull Tree addChild(@NotNull @NotNull String name)
      Description copied from interface: Tree
      Add a child with the given name. Does nothing if such a child already exists.
      Specified by:
      addChild in interface Tree
      Parameters:
      name - name of the child. A valid name does not start with a colon, is not empty and does not contain a forward slash.
      Returns:
      the Tree instance of the child with the given name.

    • setOrderableChildren

      public void setOrderableChildren(boolean enable)
      Description copied from interface: Tree
      Changes the nature of this tree such that the order of the children is kept stable. The expected behavior is as follows:

      1. Calling setOrderableChildren(true) on a tree the first time will stabilize the order of existing children. Any subsequent Tree.addChild(String) call is guaranteed to insert the new tree and the end of the child list.
      2. Calling setOrderableChildren(true) on a tree that already has its children ordered has no effect.
      3. Calling setOrderableChildren(false) on a tree that doesn't have ordered children has not effect
      4. Calling setOrderableChildren(false) on a tree with ordered children will remove the necessity to keep the child list stable. The order of children upon Tree.getChildren() is subsequently undefined.

      Calling Tree.orderBefore(String) on a tree, implicitly enables orderable children on the parent tree.

      Specified by:
      setOrderableChildren in interface Tree
      Parameters:
      enable - Enable (or disable) orderable children for this tree.

    • orderBefore

      public boolean orderBefore(@Nullable @Nullable String name)
      Description copied from interface: Tree
      Orders this Tree before the sibling tree with the given name. Calling this method for the first time on this Tree or any of its siblings will persist the current order of siblings and maintain it from this point on.
      Specified by:
      orderBefore in interface Tree
      Parameters:
      name - the name of the sibling node where this tree is ordered before. This tree will become the last sibling if name is null.
      Returns:
      false if there is no sibling with the given name or no reordering was performed; true otherwise.

    • setProperty

      public void setProperty(@NotNull @NotNull PropertyState property)
      Description copied from interface: Tree
      Set a property state
      Specified by:
      setProperty in interface Tree
      Parameters:
      property - The property state to set

    • setProperty

      public <T> void setProperty(@NotNull @NotNull String name, @NotNull T value)
      Description copied from interface: Tree
      Set a property state
      Specified by:
      setProperty in interface Tree
      Type Parameters:
      T - The type of this property. Must be one of String, Blob, byte[], Long, Integer, Double, Boolean, BigDecimal
      Parameters:
      name - The name of this property. A valid name does not start with a colon, is not empty and does not contain a forward slash.
      value - The value of this property

    • setProperty

      public <T> void setProperty(@NotNull @NotNull String name, @NotNull T value, @NotNull @NotNull Type<T> type)
      Description copied from interface: Tree
      Set a property state
      Specified by:
      setProperty in interface Tree
      Type Parameters:
      T - The type of this property.
      Parameters:
      name - The name of this property. A valid name does not start with a colon, is not empty and does not contain a forward slash.
      value - The value of this property
      type - The type of this property.

    • removeProperty

      public void removeProperty(@NotNull @NotNull String name)
      Description copied from interface: Tree
      Remove the property with the given name. This method has no effect if a property of the given name does not exist.
      Specified by:
      removeProperty in interface Tree
      Parameters:
      name - The name of the property

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object