org.geotools.util
Class CheckedHashSet<E>

java.lang.Object
  extended by java.util.AbstractCollection<E>
      extended by java.util.AbstractSet<E>
          extended by java.util.HashSet<E>
              extended by java.util.LinkedHashSet<E>
                  extended by org.geotools.util.CheckedHashSet<E>
Type Parameters:
E - The type of elements in the set.
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable, java.lang.Iterable<E>, java.util.Collection<E>, java.util.Set<E>, CheckedCollection<E>

public class CheckedHashSet<E>
extends java.util.LinkedHashSet<E>
implements CheckedCollection<E>, org.opengis.util.Cloneable

A checked and synchronized Set. 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
Version:
$Id: CheckedHashSet.java 30852 2008-07-03 15:59:42Z desruisseaux $
Author:
Jody Garnett (Refractions Research), Martin Desruisseaux (IRD)
See Also:
Collections.checkedSet(java.util.Set, java.lang.Class), Collections.synchronizedSet(java.util.Set), Serialized Form

Constructor Summary
CheckedHashSet(java.lang.Class<E> type)
          Constructs a set of the specified type.
CheckedHashSet(java.lang.Class<E> type, int capacity)
          Constructs a set of the specified type and initial capacity.
 
Method Summary
 boolean add(E element)
          Adds the specified element to this set if it is not already present.
 boolean addAll(java.util.Collection<? extends E> collection)
          Appends all of the elements in the specified collection to this set.
protected  void checkWritePermission()
          Checks if changes in this collection are allowed.
 void clear()
          Removes all of the elements from this set.
 CheckedHashSet<E> clone()
          Returns a shallow copy of this set.
 boolean contains(java.lang.Object o)
          Returns true if this set contains the specified element.
protected  void ensureValidType(E element)
          Checks the type of the specified object.
 boolean equals(java.lang.Object o)
          Compares the specified object with this set for equality.
 java.lang.Class<E> getElementType()
          Returns the element type given at construction time.
protected  java.lang.Object getLock()
          Returns the synchronization lock.
 int hashCode()
          Returns the hash code value for this set.
 boolean isEmpty()
          Returns true if this set contains no elements.
 java.util.Iterator<E> iterator()
          Returns an iterator over the elements in this set.
 boolean remove(java.lang.Object o)
          Removes the pecified element from this set.
 boolean removeAll(java.util.Collection<?> c)
          Removes all of this set's elements that are also contained in the specified collection.
 boolean retainAll(java.util.Collection<?> c)
          Retains only the elements in this set that are contained in the specified collection.
 int size()
          Returns the number of elements in this set.
 java.lang.Object[] toArray()
          Returns an array containing all of the elements in this set.
<T> T[]
toArray(T[] a)
          Returns an array containing all of the elements in this set.
 java.lang.String toString()
          Returns a string representation of this set.
 
Methods inherited from class java.util.AbstractCollection
containsAll
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface java.util.Collection
containsAll
 
Methods inherited from interface java.util.Set
containsAll
 

Constructor Detail

CheckedHashSet

public CheckedHashSet(java.lang.Class<E> type)
Constructs a set of the specified type.

Parameters:
type - The element type (should not be null).

CheckedHashSet

public CheckedHashSet(java.lang.Class<E> type,
                      int capacity)
Constructs a set of the specified type and initial capacity.

Parameters:
type - The element type (should not be null).
capacity - The initial capacity.
Since:
2.4
Method Detail

getElementType

public java.lang.Class<E> getElementType()
Returns the element type given at construction time.

Specified by:
getElementType in interface CheckedCollection<E>
Returns:
The element type.
Since:
2.4

ensureValidType

protected void ensureValidType(E element)
                        throws java.lang.IllegalArgumentException
Checks the type of the specified object. The default implementation ensure that the object is assignable to the type specified at construction time.

Parameters:
element - the object to check, or null.
Throws:
java.lang.IllegalArgumentException - if the specified element is not of the expected type.

checkWritePermission

protected void checkWritePermission()
                             throws java.lang.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:
java.lang.UnsupportedOperationException - if this collection is unmodifiable.
Since:
2.5

getLock

protected java.lang.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

iterator

public java.util.Iterator<E> iterator()
Returns an iterator over the elements in this set.

Specified by:
iterator in interface java.lang.Iterable<E>
Specified by:
iterator in interface java.util.Collection<E>
Specified by:
iterator in interface java.util.Set<E>
Overrides:
iterator in class java.util.HashSet<E>

size

public int size()
Returns the number of elements in this set.

Specified by:
size in interface java.util.Collection<E>
Specified by:
size in interface java.util.Set<E>
Overrides:
size in class java.util.HashSet<E>

isEmpty

public boolean isEmpty()
Returns true if this set contains no elements.

Specified by:
isEmpty in interface java.util.Collection<E>
Specified by:
isEmpty in interface java.util.Set<E>
Overrides:
isEmpty in class java.util.HashSet<E>

contains

public boolean contains(java.lang.Object o)
Returns true if this set contains the specified element.

Specified by:
contains in interface java.util.Collection<E>
Specified by:
contains in interface java.util.Set<E>
Overrides:
contains in class java.util.HashSet<E>

add

public boolean add(E element)
            throws java.lang.IllegalArgumentException,
                   java.lang.UnsupportedOperationException
Adds the specified element to this set if it is not already present.

Specified by:
add in interface java.util.Collection<E>
Specified by:
add in interface java.util.Set<E>
Overrides:
add in class java.util.HashSet<E>
Parameters:
element - element to be added to this set.
Returns:
true if the set did not already contain the specified element.
Throws:
java.lang.IllegalArgumentException - if the specified element is not of the expected type.
java.lang.UnsupportedOperationException - if this collection is unmodifiable.

addAll

public boolean addAll(java.util.Collection<? extends E> collection)
               throws java.lang.IllegalArgumentException,
                      java.lang.UnsupportedOperationException
Appends all of the elements in the specified collection to this set.

Specified by:
addAll in interface java.util.Collection<E>
Specified by:
addAll in interface java.util.Set<E>
Overrides:
addAll in class java.util.AbstractCollection<E>
Parameters:
collection - the elements to be inserted into this set.
Returns:
true if this set changed as a result of the call.
Throws:
java.lang.IllegalArgumentException - if at least one element is not of the expected type.
java.lang.UnsupportedOperationException - if this collection is unmodifiable.

remove

public boolean remove(java.lang.Object o)
               throws java.lang.UnsupportedOperationException
Removes the pecified element from this set.

Specified by:
remove in interface java.util.Collection<E>
Specified by:
remove in interface java.util.Set<E>
Overrides:
remove in class java.util.HashSet<E>
Throws:
java.lang.UnsupportedOperationException - if this collection is unmodifiable.

removeAll

public boolean removeAll(java.util.Collection<?> c)
                  throws java.lang.UnsupportedOperationException
Removes all of this set's elements that are also contained in the specified collection.

Specified by:
removeAll in interface java.util.Collection<E>
Specified by:
removeAll in interface java.util.Set<E>
Overrides:
removeAll in class java.util.AbstractSet<E>
Throws:
java.lang.UnsupportedOperationException - if this collection is unmodifiable.

retainAll

public boolean retainAll(java.util.Collection<?> c)
                  throws java.lang.UnsupportedOperationException
Retains only the elements in this set that are contained in the specified collection.

Specified by:
retainAll in interface java.util.Collection<E>
Specified by:
retainAll in interface java.util.Set<E>
Overrides:
retainAll in class java.util.AbstractCollection<E>
Throws:
java.lang.UnsupportedOperationException - if this collection is unmodifiable.

clear

public void clear()
           throws java.lang.UnsupportedOperationException
Removes all of the elements from this set.

Specified by:
clear in interface java.util.Collection<E>
Specified by:
clear in interface java.util.Set<E>
Overrides:
clear in class java.util.HashSet<E>
Throws:
java.lang.UnsupportedOperationException - if this collection is unmodifiable.

toArray

public java.lang.Object[] toArray()
Returns an array containing all of the elements in this set.

Specified by:
toArray in interface java.util.Collection<E>
Specified by:
toArray in interface java.util.Set<E>
Overrides:
toArray in class java.util.AbstractCollection<E>

toArray

public <T> T[] toArray(T[] a)
Returns an array containing all of the elements in this set.

Specified by:
toArray in interface java.util.Collection<E>
Specified by:
toArray in interface java.util.Set<E>
Overrides:
toArray in class java.util.AbstractCollection<E>
Type Parameters:
T - The type of array elements.

toString

public java.lang.String toString()
Returns a string representation of this set.

Overrides:
toString in class java.util.AbstractCollection<E>

equals

public boolean equals(java.lang.Object o)
Compares the specified object with this set for equality.

Specified by:
equals in interface java.util.Collection<E>
Specified by:
equals in interface java.util.Set<E>
Overrides:
equals in class java.util.AbstractSet<E>

hashCode

public int hashCode()
Returns the hash code value for this set.

Specified by:
hashCode in interface java.util.Collection<E>
Specified by:
hashCode in interface java.util.Set<E>
Overrides:
hashCode in class java.util.AbstractSet<E>

clone

public CheckedHashSet<E> clone()
Returns a shallow copy of this set.

Overrides:
clone in class java.util.HashSet<E>
Returns:
A shallow copy of this set.


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