org.geotools.util

Class CheckedHashMap<K,V>

Object

AbstractMap<K,V>

HashMap<K,V>

LinkedHashMap<K,V>

CheckedHashMap<K,V>

Type Parameters:

K - The type of keys in the map.

V - The type of values in the map.

All Implemented Interfaces:

Serializable, Cloneable, Map<K,V>

public class CheckedHashMap<K,V>
extends LinkedHashMap<K,V>
implements Cloneable

A checked and synchronized Map. Type checks are performed at run-time in addition of compile-time checks. The synchronization lock can be modified at runtime by overriding the getLock() method.

This class is similar to using the wrappers provided in Collections, minus the cost of indirection levels and with the addition of overrideable methods.

Since:

2.1

Author:

Jody Garnett (Refractions Research), Martin Desruisseaux (IRD)

See Also:

Collections#checkedMap, Collections#synchronizedMap, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Constructor Summary

Constructors

Constructor and Description
CheckedHashMap(Class<K> keyType, Class<V> valueType) Constructs a map of the specified type.

Method Summary

Modifier and Type	Method and Description
protected void	checkWritePermission() Checks if changes in this collection are allowed.
void	clear() Removes all of the elements from this map.
CheckedHashMap<K,V>	clone() Returns a shallow copy of this map.
boolean	containsKey(Object key) Returns true if this map contains the specified key.
boolean	containsValue(Object value) Returns true if this map contains the specified value.
boolean	equals(Object o) Compares the specified object with this map for equality.
V	get(Object key) Returns the value to which the specified key is mapped, or null if none.
protected Object	getLock() Returns the synchronization lock.
int	hashCode() Returns the hash code value for this map.
boolean	isEmpty() Returns true if this map contains no elements.
V	put(K key, V value) Associates the specified value with the specified key in this map.
void	putAll(Map<? extends K,? extends V> m) Copies all of the mappings from the specified map to this map.
V	remove(Object key) Removes the mapping for the specified key from this map if present.
int	size() Returns the number of elements in this map.
String	toString() Returns a string representation of this map.

Methods inherited from class LinkedHashMap

entrySet, forEach, getOrDefault, keySet, removeEldestEntry, replaceAll, values

Methods inherited from class HashMap

compute, computeIfAbsent, computeIfPresent, merge, putIfAbsent, remove, replace, replace

Methods inherited from class Object

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

Methods inherited from interface Map

compute, computeIfAbsent, computeIfPresent, merge, putIfAbsent, remove, replace, replace

Constructor Detail

CheckedHashMap

public CheckedHashMap(Class<K> keyType,
                      Class<V> valueType)

Constructs a map of the specified type.

Parameters:

keyType - The key type (should not be null).

valueType - The value type (should not be null).

Method Detail

checkWritePermission

protected void checkWritePermission()
                             throws UnsupportedOperationException

Checks if changes in this collection are allowed. This method is automatically invoked after this collection got the lock and before any operation that may change the content. The default implementation does nothing (i.e. this collection is modifiable). Subclasses should override this method if they want to control write access.

Throws:

UnsupportedOperationException - if this collection is unmodifiable.

Since:

2.5

getLock

protected Object getLock()

Returns the synchronization lock. The default implementation returns this. Subclasses that override this method should be careful to update the lock reference when this set is cloned.

Returns:

The synchronization lock.

Since:

2.5

size

public int size()

Returns the number of elements in this map.

Specified by:

size in interface Map<K,V>

Overrides:

size in class HashMap<K,V>

isEmpty

public boolean isEmpty()

Returns true if this map contains no elements.

Specified by:

isEmpty in interface Map<K,V>

Overrides:

isEmpty in class HashMap<K,V>

containsKey

public boolean containsKey(Object key)

Returns true if this map contains the specified key.

Specified by:

containsKey in interface Map<K,V>

Overrides:

containsKey in class HashMap<K,V>

containsValue

public boolean containsValue(Object value)

Returns true if this map contains the specified value.

Specified by:

containsValue in interface Map<K,V>

Overrides:

containsValue in class LinkedHashMap<K,V>

get

public V get(Object key)

Returns the value to which the specified key is mapped, or null if none.

Specified by:

get in interface Map<K,V>

Overrides:

get in class LinkedHashMap<K,V>

put

public V put(K key,
             V value)
      throws IllegalArgumentException,
             UnsupportedOperationException

Associates the specified value with the specified key in this map. If the map previously contained a mapping for this key, the old value is replaced.

Specified by:

put in interface Map<K,V>

Overrides:

put in class HashMap<K,V>

Parameters:

key - key with which the specified value is to be associated.

value - value to be associated with the specified key.

Returns:

previous value associated with specified key, or null.

Throws:

IllegalArgumentException - if the key or the value is not of the expected type.

UnsupportedOperationException - if this collection is unmodifiable.

putAll

public void putAll(Map<? extends K,? extends V> m)
            throws UnsupportedOperationException

Copies all of the mappings from the specified map to this map.

Specified by:

putAll in interface Map<K,V>

Overrides:

putAll in class HashMap<K,V>

Throws:

UnsupportedOperationException - if this collection is unmodifiable.

remove

public V remove(Object key)
         throws UnsupportedOperationException

Removes the mapping for the specified key from this map if present.

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class HashMap<K,V>

Throws:

UnsupportedOperationException - if this collection is unmodifiable.

clear

public void clear()
           throws UnsupportedOperationException

Removes all of the elements from this map.

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class LinkedHashMap<K,V>

Throws:

UnsupportedOperationException - if this collection is unmodifiable.

toString

public String toString()

Returns a string representation of this map.

Overrides:

toString in class AbstractMap<K,V>

equals

public boolean equals(Object o)

Compares the specified object with this map for equality.

Specified by:

equals in interface Map<K,V>

Overrides:

equals in class AbstractMap<K,V>

hashCode

public int hashCode()

Returns the hash code value for this map.

Specified by:

hashCode in interface Map<K,V>

Overrides:

hashCode in class AbstractMap<K,V>

clone

public CheckedHashMap<K,V> clone()

Returns a shallow copy of this map.

Overrides:

clone in class HashMap<K,V>

Returns:

A shallow copy of this map.

See Also:

Object.clone()