org.eclipse.rdf4j.query.impl

## Class EmptyBindingSet

- java.lang.Object
- - org.eclipse.rdf4j.query.impl.EmptyBindingSet

- All Implemented Interfaces:
    Serializable, Iterable<Binding>, BindingSet

      public class EmptyBindingSet
      extends Object
      implements BindingSet

  An immutable empty BindingSet.
  Author:
    Arjohn Kampman
  See Also:
    Serialized Form

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `EmptyBindingSet()`

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `equals(Object o)` Compares a BindingSet object to another object.
    `Binding` | `getBinding(String bindingName)` Gets the binding with the specified name from this BindingSet.
    `Set<String>` | `getBindingNames()` Gets the names of the bindings in this BindingSet.
    `static BindingSet` | `getInstance()`
    `Value` | `getValue(String bindingName)` Gets the value of the binding with the specified name from this BindingSet.
    `boolean` | `hasBinding(String bindingName)` Checks whether this BindingSet has a binding with the specified name.
    `int` | `hashCode()` The hash code of a binding is defined as the bit-wise XOR of the hash codes of its bindings:
    `Iterator<Binding>` | `iterator()` Creates an iterator over the bindings in this BindingSet.
    `int` | `size()` Returns the number of bindings in this BindingSet.
    `String` | `toString()`

    - ### Methods inherited from class java.lang.Object

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

    - ### Methods inherited from interface java.lang.Iterable

      `forEach, spliterator`

- - ### Constructor Detail

    - #### EmptyBindingSet

          public EmptyBindingSet()

  - ### Method Detail

    - #### getInstance

          public static BindingSet getInstance()

    - #### iterator

          public Iterator<Binding> iterator()

      Description copied from interface: `BindingSet`
      Creates an iterator over the bindings in this BindingSet. This only returns bindings with non-null values. An implementation is free to return the bindings in arbitrary order.
      Specified by:
        `iterator` in interface `Iterable<Binding>`
      Specified by:
        `iterator` in interface `BindingSet`

    - #### getBindingNames

          public Set<String> getBindingNames()

      Description copied from interface: `BindingSet`
      Gets the names of the bindings in this BindingSet.
      Specified by:
        `getBindingNames` in interface `BindingSet`
      Returns:
        A set of binding names.

    - #### getBinding

          public Binding getBinding(String bindingName)

      Description copied from interface: `BindingSet`
      Gets the binding with the specified name from this BindingSet.
      Specified by:
        `getBinding` in interface `BindingSet`
      Parameters:
        `bindingName` - The name of the binding.
      Returns:
        The binding with the specified name, or `null` if there is no such binding in this BindingSet.

    - #### hasBinding

          public boolean hasBinding(String bindingName)

      Description copied from interface: `BindingSet`
      Checks whether this BindingSet has a binding with the specified name.
      Specified by:
        `hasBinding` in interface `BindingSet`
      Parameters:
        `bindingName` - The name of the binding.
      Returns:
        `true` if this BindingSet has a binding with the specified name, `false` otherwise.

    - #### getValue

          public Value getValue(String bindingName)

      Description copied from interface: `BindingSet`
      Gets the value of the binding with the specified name from this BindingSet.
      Specified by:
        `getValue` in interface `BindingSet`
      Parameters:
        `bindingName` - The name of the binding.
      Returns:
        The value of the binding with the specified name, or `null` if there is no such binding in this BindingSet.

    - #### size

          public int size()

      Description copied from interface: `BindingSet`
      Returns the number of bindings in this BindingSet.
      Specified by:
        `size` in interface `BindingSet`
      Returns:
        The number of bindings in this BindingSet.

    - #### equals

          public boolean equals(Object o)

      Description copied from interface: `BindingSet`
      Compares a BindingSet object to another object.
      Specified by:
        `equals` in interface `BindingSet`
      Overrides:
        `equals` in class `Object`
      Parameters:
        `o` - The object to compare this binding to.
      Returns:
        `true` if the other object is an instance of `BindingSet` and it contains the same set of bindings (disregarding order), `false` otherwise.

    - #### hashCode

          public int hashCode()

      Description copied from interface: `BindingSet`
      The hash code of a binding is defined as the bit-wise XOR of the hash codes of its bindings:

           int hashCode = 0;

           for (Binding binding : this) {
                  hashCode ˆ= binding.getName().hashCode() ˆ binding.getValue().hashCode();
           }

      Note: the calculated hash code intentionally does not depend on the order in which the bindings are iterated over.
      Specified by:
        `hashCode` in interface `BindingSet`
      Overrides:
        `hashCode` in class `Object`
      Returns:
        A hash code for the BindingSet.

    - #### toString

          public String toString()

      Overrides:
        `toString` in class `Object`

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