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src/java.base/share/classes/java/util/AbstractSet.java
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*** 24,47 ****
*/
package java.util;
/**
! * This class provides a skeletal implementation of the <tt>Set</tt>
* interface to minimize the effort required to implement this
* interface. <p>
*
* The process of implementing a set by extending this class is identical
* to that of implementing a Collection by extending AbstractCollection,
* except that all of the methods and constructors in subclasses of this
! * class must obey the additional constraints imposed by the <tt>Set</tt>
* interface (for instance, the add method must not permit addition of
* multiple instances of an object to a set).<p>
*
* Note that this class does not override any of the implementations from
! * the <tt>AbstractCollection</tt> class. It merely adds implementations
! * for <tt>equals</tt> and <tt>hashCode</tt>.<p>
*
* This class is a member of the
* <a href="{@docRoot}/../technotes/guides/collections/index.html">
* Java Collections Framework</a>.
*
--- 24,47 ----
*/
package java.util;
/**
! * This class provides a skeletal implementation of the {@code Set}
* interface to minimize the effort required to implement this
* interface. <p>
*
* The process of implementing a set by extending this class is identical
* to that of implementing a Collection by extending AbstractCollection,
* except that all of the methods and constructors in subclasses of this
! * class must obey the additional constraints imposed by the {@code Set}
* interface (for instance, the add method must not permit addition of
* multiple instances of an object to a set).<p>
*
* Note that this class does not override any of the implementations from
! * the {@code AbstractCollection} class. It merely adds implementations
! * for {@code equals} and {@code hashCode}.<p>
*
* This class is a member of the
* <a href="{@docRoot}/../technotes/guides/collections/index.html">
* Java Collections Framework</a>.
*
*** 65,88 ****
// Comparison and hashing
/**
* Compares the specified object with this set for equality. Returns
! * <tt>true</tt> if the given object is also a set, the two sets have
* the same size, and every member of the given set is contained in
! * this set. This ensures that the <tt>equals</tt> method works
! * properly across different implementations of the <tt>Set</tt>
* interface.<p>
*
* This implementation first checks if the specified object is this
! * set; if so it returns <tt>true</tt>. Then, it checks if the
* specified object is a set whose size is identical to the size of
* this set; if not, it returns false. If so, it returns
! * <tt>containsAll((Collection) o)</tt>.
*
* @param o object to be compared for equality with this set
! * @return <tt>true</tt> if the specified object is equal to this set
*/
public boolean equals(Object o) {
if (o == this)
return true;
--- 65,88 ----
// Comparison and hashing
/**
* Compares the specified object with this set for equality. Returns
! * {@code true} if the given object is also a set, the two sets have
* the same size, and every member of the given set is contained in
! * this set. This ensures that the {@code equals} method works
! * properly across different implementations of the {@code Set}
* interface.<p>
*
* This implementation first checks if the specified object is this
! * set; if so it returns {@code true}. Then, it checks if the
* specified object is a set whose size is identical to the size of
* this set; if not, it returns false. If so, it returns
! * {@code containsAll((Collection) o)}.
*
* @param o object to be compared for equality with this set
! * @return {@code true} if the specified object is equal to this set
*/
public boolean equals(Object o) {
if (o == this)
return true;
*** 101,118 ****
}
/**
* Returns the hash code value for this set. The hash code of a set is
* defined to be the sum of the hash codes of the elements in the set,
! * where the hash code of a <tt>null</tt> element is defined to be zero.
! * This ensures that <tt>s1.equals(s2)</tt> implies that
! * <tt>s1.hashCode()==s2.hashCode()</tt> for any two sets <tt>s1</tt>
! * and <tt>s2</tt>, as required by the general contract of
* {@link Object#hashCode}.
*
* <p>This implementation iterates over the set, calling the
! * <tt>hashCode</tt> method on each element in the set, and adding up
* the results.
*
* @return the hash code value for this set
* @see Object#equals(Object)
* @see Set#equals(Object)
--- 101,118 ----
}
/**
* Returns the hash code value for this set. The hash code of a set is
* defined to be the sum of the hash codes of the elements in the set,
! * where the hash code of a {@code null} element is defined to be zero.
! * This ensures that {@code s1.equals(s2)} implies that
! * {@code s1.hashCode()==s2.hashCode()} for any two sets {@code s1}
! * and {@code s2}, as required by the general contract of
* {@link Object#hashCode}.
*
* <p>This implementation iterates over the set, calling the
! * {@code hashCode} method on each element in the set, and adding up
* the results.
*
* @return the hash code value for this set
* @see Object#equals(Object)
* @see Set#equals(Object)
*** 134,161 ****
* collection is also a set, this operation effectively modifies this
* set so that its value is the <i>asymmetric set difference</i> of
* the two sets.
*
* <p>This implementation determines which is the smaller of this set
! * and the specified collection, by invoking the <tt>size</tt>
* method on each. If this set has fewer elements, then the
* implementation iterates over this set, checking each element
* returned by the iterator in turn to see if it is contained in
* the specified collection. If it is so contained, it is removed
! * from this set with the iterator's <tt>remove</tt> method. If
* the specified collection has fewer elements, then the
* implementation iterates over the specified collection, removing
* from this set each element returned by the iterator, using this
! * set's <tt>remove</tt> method.
*
* <p>Note that this implementation will throw an
! * <tt>UnsupportedOperationException</tt> if the iterator returned by the
! * <tt>iterator</tt> method does not implement the <tt>remove</tt> method.
*
* @param c collection containing elements to be removed from this set
! * @return <tt>true</tt> if this set changed as a result of the call
! * @throws UnsupportedOperationException if the <tt>removeAll</tt> operation
* is not supported by this set
* @throws ClassCastException if the class of an element of this set
* is incompatible with the specified collection
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws NullPointerException if this set contains a null element and the
--- 134,161 ----
* collection is also a set, this operation effectively modifies this
* set so that its value is the <i>asymmetric set difference</i> of
* the two sets.
*
* <p>This implementation determines which is the smaller of this set
! * and the specified collection, by invoking the {@code size}
* method on each. If this set has fewer elements, then the
* implementation iterates over this set, checking each element
* returned by the iterator in turn to see if it is contained in
* the specified collection. If it is so contained, it is removed
! * from this set with the iterator's {@code remove} method. If
* the specified collection has fewer elements, then the
* implementation iterates over the specified collection, removing
* from this set each element returned by the iterator, using this
! * set's {@code remove} method.
*
* <p>Note that this implementation will throw an
! * {@code UnsupportedOperationException} if the iterator returned by the
! * {@code iterator} method does not implement the {@code remove} method.
*
* @param c collection containing elements to be removed from this set
! * @return {@code true} if this set changed as a result of the call
! * @throws UnsupportedOperationException if the {@code removeAll} operation
* is not supported by this set
* @throws ClassCastException if the class of an element of this set
* is incompatible with the specified collection
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws NullPointerException if this set contains a null element and the
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