## org.jfree.data.general
Class DefaultKeyedValueDataset

    java.lang.Object
      org.jfree.data.general.AbstractDataset
          org.jfree.data.general.DefaultKeyedValueDataset

All Implemented Interfaces:
  java.io.ObjectInputValidation, java.io.Serializable, java.lang.Cloneable, Dataset, KeyedValueDataset, KeyedValue, Value

    public class DefaultKeyedValueDataset

extends AbstractDataset
implements KeyedValueDataset, java.io.Serializable

A default implementation of the `KeyedValueDataset` interface.

See Also:
  Serialized Form

Constructor Summary
`DefaultKeyedValueDataset()` Constructs a new dataset, initially empty.
`DefaultKeyedValueDataset(java.lang.Comparable key, java.lang.Number value)` Creates a new dataset with the specified initial value.
`DefaultKeyedValueDataset(KeyedValue data)` Creates a new dataset that uses the data from a `KeyedValue` instance.

Method Summary
`java.lang.Object` `clone()` Creates a clone of the dataset.
`boolean` `equals(java.lang.Object obj)` Tests this dataset for equality with an arbitrary object.
`java.lang.Comparable` `getKey()` Returns the key associated with the value, or `null` if the dataset has no data item.
`java.lang.Number` `getValue()` Returns the value.
`int` `hashCode()` Returns a hash code.
`void` `setValue(java.lang.Comparable key, java.lang.Number value)` Sets the value for the dataset and sends a `DatasetChangeEvent` to all registered listeners.
`void` `updateValue(java.lang.Number value)` Updates the value.

Methods inherited from class org.jfree.data.general.AbstractDataset
`addChangeListener, fireDatasetChanged, getGroup, hasListener, notifyListeners, removeChangeListener, setGroup, validateObject`

Methods inherited from class java.lang.Object
`finalize, getClass, notify, notifyAll, toString, wait, wait, wait`

Methods inherited from interface org.jfree.data.general.Dataset
`addChangeListener, getGroup, removeChangeListener, setGroup`

Constructor Detail

### DefaultKeyedValueDataset

    public DefaultKeyedValueDataset()

  Constructs a new dataset, initially empty.

### DefaultKeyedValueDataset

    public DefaultKeyedValueDataset(java.lang.Comparable key,
                                    java.lang.Number value)

  Creates a new dataset with the specified initial value.

  Parameters:
    `key` - the key.
    `value` - the value (`null` permitted).

### DefaultKeyedValueDataset

    public DefaultKeyedValueDataset(KeyedValue data)

  Creates a new dataset that uses the data from a `KeyedValue` instance.

  Parameters:
    `data` - the data (`null` permitted).

Method Detail

### getKey

    public java.lang.Comparable getKey()

  Returns the key associated with the value, or `null` if the dataset has no data item.

  Specified by:
    `getKey` in interface `KeyedValue`
  Returns:
    The key.

### getValue

    public java.lang.Number getValue()

  Returns the value.

  Specified by:
    `getValue` in interface `Value`
  Returns:
    The value (possibly `null`).

### updateValue

    public void updateValue(java.lang.Number value)

  Updates the value.

  Parameters:
    `value` - the new value (`null` permitted).

### setValue

    public void setValue(java.lang.Comparable key,
                         java.lang.Number value)

  Sets the value for the dataset and sends a `DatasetChangeEvent` to all registered listeners.

  Parameters:
    `key` - the key.
    `value` - the value (`null` permitted).

### equals

    public boolean equals(java.lang.Object obj)

  Tests this dataset for equality with an arbitrary object.

  Overrides:
    `equals` in class `java.lang.Object`
  Parameters:
    `obj` - the object.
  Returns:
    A boolean.

### hashCode

    public int hashCode()

  Returns a hash code.

  Overrides:
    `hashCode` in class `java.lang.Object`
  Returns:
    A hash code.

### clone

    public java.lang.Object clone()
                           throws java.lang.CloneNotSupportedException

  Creates a clone of the dataset.

  Overrides:
    `clone` in class `AbstractDataset`
  Returns:
    A clone.
  Throws:
    `java.lang.CloneNotSupportedException` - This class will not throw this exception, but subclasses (if any) might.