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 * Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
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 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package javax.print.attribute;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.HashMap;


Class HashAttributeSet provides an AttributeSet implementation with characteristics of a hash map. 
Author: Alan Kaminsky
/**
 * Class HashAttributeSet provides an {@code AttributeSet}
 * implementation with characteristics of a hash map.
 *
 * @author  Alan Kaminsky
 */
public class HashAttributeSet implements AttributeSet, Serializable {

    private static final long serialVersionUID = 5311560590283707917L;

    
The interface of which all members of this attribute set must be an instance. It is assumed to be interface Attribute or a subinterface thereof. 
@serial
/**
     * The interface of which all members of this attribute set must be an
     * instance. It is assumed to be interface {@link Attribute Attribute}
     * or a subinterface thereof.
     * @serial
     */
    private Class<?> myInterface;

    /*
     * A HashMap used by the implementation.
     * The serialised form doesn't include this instance variable.
     */
    private transient HashMap<Class<?>, Attribute> attrMap = new HashMap<>();

    
Write the instance to a stream (ie serialize the object)

@serialData
The serialized form of an attribute set explicitly writes the
number of attributes in the set, and each of the attributes.
This does not guarantee equality of serialized forms since
the order in which the attributes are written is not defined.
/**
     * Write the instance to a stream (ie serialize the object)
     *
     * @serialData
     * The serialized form of an attribute set explicitly writes the
     * number of attributes in the set, and each of the attributes.
     * This does not guarantee equality of serialized forms since
     * the order in which the attributes are written is not defined.
     */
    private void writeObject(ObjectOutputStream s) throws IOException {

        s.defaultWriteObject();
        Attribute [] attrs = toArray();
        s.writeInt(attrs.length);
        for (int i = 0; i < attrs.length; i++) {
            s.writeObject(attrs[i]);
        }
    }

    
Reconstitute an instance from a stream that is, deserialize it).

/**
     * Reconstitute an instance from a stream that is, deserialize it).
     */
    private void readObject(ObjectInputStream s)
        throws ClassNotFoundException, IOException {

        s.defaultReadObject();
        attrMap = new HashMap<>();
        int count = s.readInt();
        Attribute attr;
        for (int i = 0; i < count; i++) {
            attr = (Attribute)s.readObject();
            add(attr);
        }
    }

    
Construct a new, empty attribute set.

/**
     * Construct a new, empty attribute set.
     */
    public HashAttributeSet() {
        this(Attribute.class);
    }

    
Construct a new attribute set,
initially populated with the given attribute.

Params:
  • attribute –  Attribute value to add to the set.
Throws:
/**
     * Construct a new attribute set,
     * initially populated with the given attribute.
     *
     * @param  attribute  Attribute value to add to the set.
     *
     * @exception  NullPointerException
     *     (unchecked exception) Thrown if {@code attribute} is null.
     */
    public HashAttributeSet(Attribute attribute) {
        this (attribute, Attribute.class);
    }

    
Construct a new attribute set, initially populated with the values from the given array. The new attribute set is populated by adding the elements of attributes array to the set in sequence, starting at index 0. Thus, later array elements may replace earlier array elements if the array contains duplicate attribute values or attribute categories. 
Params:
  • attributes –  Array of attribute values to add to the set.
                   If null, an empty attribute set is constructed.
Throws:
/**
     * Construct a new attribute set,
     * initially populated with the values from the
     * given array. The new attribute set is populated by
     * adding the elements of {@code attributes} array to the set in
     * sequence, starting at index 0. Thus, later array elements may replace
     * earlier array elements if the array contains duplicate attribute
     * values or attribute categories.
     *
     * @param  attributes  Array of attribute values to add to the set.
     *                    If null, an empty attribute set is constructed.
     *
     * @exception  NullPointerException
     *     (unchecked exception) Thrown if any element of
     *     {@code attributes} is null.
     */
    public HashAttributeSet(Attribute[] attributes) {
        this (attributes, Attribute.class);
    }

    
Construct a new attribute set,
initially populated with the values from the  given set.

Params:
  • attributes – Set of attributes from which to initialise this set.
                If null, an empty attribute set is constructed.
/**
     * Construct a new attribute set,
     * initially populated with the values from the  given set.
     *
     * @param  attributes Set of attributes from which to initialise this set.
     *                 If null, an empty attribute set is constructed.
     *
     */
    public HashAttributeSet(AttributeSet attributes) {
        this (attributes, Attribute.class);
    }

    
Construct a new, empty attribute set, where the members of
the attribute set are restricted to the given interface.

Params:
  • interfaceName –  The interface of which all members of this attribute set must be an instance. It is assumed to be interface Attribute or a subinterface thereof.
Throws:
/**
     * Construct a new, empty attribute set, where the members of
     * the attribute set are restricted to the given interface.
     *
     * @param  interfaceName  The interface of which all members of this
     *                     attribute set must be an instance. It is assumed to
     *                     be interface {@link Attribute Attribute} or a
     *                     subinterface thereof.
     * @exception NullPointerException if interfaceName is null.
     */
    protected HashAttributeSet(Class<?> interfaceName) {
        if (interfaceName == null) {
            throw new NullPointerException("null interface");
        }
        myInterface = interfaceName;
    }

    
Construct a new attribute set, initially populated with the given
attribute, where the members of the attribute set are restricted to the
given interface.

Params:
  • attribute –      Attribute value to add to the set.
  • interfaceName –  The interface of which all members of this attribute set must be an instance. It is assumed to be interface Attribute or a subinterface thereof.
Throws:
/**
     * Construct a new attribute set, initially populated with the given
     * attribute, where the members of the attribute set are restricted to the
     * given interface.
     *
     * @param  attribute      Attribute value to add to the set.
     * @param  interfaceName  The interface of which all members of this
     *                    attribute set must be an instance. It is assumed to
     *                    be interface {@link Attribute Attribute} or a
     *                    subinterface thereof.
     *
     * @exception  NullPointerException
     *     (unchecked exception) Thrown if {@code attribute} is null.
     * @exception NullPointerException if interfaceName is null.
     * @exception  ClassCastException
     *     (unchecked exception) Thrown if {@code attribute} is not an
     *     instance of {@code interfaceName}.
     */
    protected HashAttributeSet(Attribute attribute, Class<?> interfaceName) {
        if (interfaceName == null) {
            throw new NullPointerException("null interface");
        }
        myInterface = interfaceName;
        add (attribute);
    }

    
Construct a new attribute set, where the members of the attribute set are restricted to the given interface. The new attribute set is populated by adding the elements of attributes array to the set in sequence, starting at index 0. Thus, later array elements may replace earlier array elements if the array contains duplicate attribute values or attribute categories. 
Params:
  • attributes – Array of attribute values to add to the set. If
                   null, an empty attribute set is constructed.
  • interfaceName –  The interface of which all members of this attribute set must be an instance. It is assumed to be interface Attribute or a subinterface thereof.
Throws:
/**
     * Construct a new attribute set, where the members of the attribute
     * set are restricted to the given interface.
     * The new attribute set is populated
     * by adding the elements of {@code attributes} array to the set in
     * sequence, starting at index 0. Thus, later array elements may replace
     * earlier array elements if the array contains duplicate attribute
     * values or attribute categories.
     *
     * @param  attributes Array of attribute values to add to the set. If
     *                    null, an empty attribute set is constructed.
     * @param  interfaceName  The interface of which all members of this
     *                    attribute set must be an instance. It is assumed to
     *                    be interface {@link Attribute Attribute} or a
     *                    subinterface thereof.
     *
     * @exception  NullPointerException
     *     (unchecked exception) Thrown if any element of
     * {@code attributes} is null.
     * @exception NullPointerException if interfaceName is null.
     * @exception  ClassCastException
     *     (unchecked exception) Thrown if any element of
     * {@code attributes} is not an instance of
     * {@code interfaceName}.
     */
    protected HashAttributeSet(Attribute[] attributes, Class<?> interfaceName) {
        if (interfaceName == null) {
            throw new NullPointerException("null interface");
        }
        myInterface = interfaceName;
        int n = attributes == null ? 0 : attributes.length;
        for (int i = 0; i < n; ++ i) {
            add (attributes[i]);
        }
    }

    
Construct a new attribute set, initially populated with the
values from the  given set where the members of the attribute
set are restricted to the given interface.

Params:
  • attributes – set of attribute values to initialise the set. If
                   null, an empty attribute set is constructed.
  • interfaceName –  The interface of which all members of this attribute set must be an instance. It is assumed to be interface Attribute or a subinterface thereof.
Throws:
  • ClassCastException –  (unchecked exception) Thrown if any element of attributes is not an instance of interfaceName.
/**
     * Construct a new attribute set, initially populated with the
     * values from the  given set where the members of the attribute
     * set are restricted to the given interface.
     *
     * @param  attributes set of attribute values to initialise the set. If
     *                    null, an empty attribute set is constructed.
     * @param  interfaceName  The interface of which all members of this
     *                    attribute set must be an instance. It is assumed to
     *                    be interface {@link Attribute Attribute} or a
     *                    subinterface thereof.
     *
     * @exception  ClassCastException
     *     (unchecked exception) Thrown if any element of
     * {@code attributes} is not an instance of
     * {@code interfaceName}.
     */
    protected HashAttributeSet(AttributeSet attributes, Class<?> interfaceName) {
      myInterface = interfaceName;
      if (attributes != null) {
        Attribute[] attribArray = attributes.toArray();
        int n = attribArray == null ? 0 : attribArray.length;
        for (int i = 0; i < n; ++ i) {
          add (attribArray[i]);
        }
      }
    }

    
Returns the attribute value which this attribute set contains in the given attribute category. Returns null if this attribute set does not contain any attribute value in the given attribute category. 
Params:
  • category –  Attribute category whose associated attribute value is to be returned. It must be a Class that implements interface 
                  Attribute.
Throws:
Returns: The attribute value in the given attribute category contained in this attribute set, or null if this attribute set does not contain any attribute value in the given attribute category.
/**
     * Returns the attribute value which this attribute set contains in the
     * given attribute category. Returns {@code null} if this attribute set
     * does not contain any attribute value in the given attribute category.
     *
     * @param  category  Attribute category whose associated attribute value
     *                   is to be returned. It must be a
     *                   {@link java.lang.Class Class}
     *                   that implements interface {@link Attribute
     *                   Attribute}.
     *
     * @return  The attribute value in the given attribute category contained
     *          in this attribute set, or {@code null} if this attribute set
     *          does not contain any attribute value in the given attribute
     *          category.
     *
     * @throws  NullPointerException
     *     (unchecked exception) Thrown if the {@code category} is null.
     * @throws  ClassCastException
     *     (unchecked exception) Thrown if the {@code category} is not a
     *     {@link java.lang.Class Class} that implements interface {@link
     *     Attribute Attribute}.
     */
    public Attribute get(Class<?> category) {
        return attrMap.get(AttributeSetUtilities.
                           verifyAttributeCategory(category,
                                                   Attribute.class));
    }

    
Adds the specified attribute to this attribute set if it is not
already present, first removing any existing in the same
attribute category as the specified attribute value.

Params:
  • attribute –  Attribute value to be added to this attribute set.
Throws:
Returns: true if this attribute set changed as a result of the call, i.e., the given attribute value was not already a member of this attribute set.
/**
     * Adds the specified attribute to this attribute set if it is not
     * already present, first removing any existing in the same
     * attribute category as the specified attribute value.
     *
     * @param  attribute  Attribute value to be added to this attribute set.
     *
     * @return  {@code true} if this attribute set changed as a result of the
     *          call, i.e., the given attribute value was not already a
     *          member of this attribute set.
     *
     * @throws  NullPointerException
     *    (unchecked exception) Thrown if the {@code attribute} is null.
     * @throws  UnmodifiableSetException
     *    (unchecked exception) Thrown if this attribute set does not support
     *     the {@code add()} operation.
     */
    public boolean add(Attribute attribute) {
        Object oldAttribute =
            attrMap.put(attribute.getCategory(),
                        AttributeSetUtilities.
                        verifyAttributeValue(attribute, myInterface));
        return (!attribute.equals(oldAttribute));
    }

    
Removes any attribute for this category from this attribute set if present. If category is null, then remove() does nothing and returns false. 
Params:
  • category – Attribute category to be removed from this
                 attribute set.
Throws:
  • UnmodifiableSetException –  (unchecked exception) Thrown if this attribute set does not support the remove() operation.
Returns: true if this attribute set changed as a result of the call, i.e., the given attribute category had been a member of this attribute set.
/**
     * Removes any attribute for this category from this attribute set if
     * present. If {@code category} is null, then
     * {@code remove()} does nothing and returns {@code false}.
     *
     * @param  category Attribute category to be removed from this
     *                  attribute set.
     *
     * @return  {@code true} if this attribute set changed as a result of the
     *         call, i.e., the given attribute category had been a member of
     *         this attribute set.
     *
     * @throws  UnmodifiableSetException
     *     (unchecked exception) Thrown if this attribute set does not
     *     support the {@code remove()} operation.
     */
    public boolean remove(Class<?> category) {
        return
            category != null &&
            AttributeSetUtilities.
            verifyAttributeCategory(category, Attribute.class) != null &&
            attrMap.remove(category) != null;
    }

    
Removes the specified attribute from this attribute set if present. If attribute is null, then remove() does nothing and returns false. 
Params:
  • attribute – Attribute value to be removed from this attribute set.
Throws:
  • UnmodifiableSetException –  (unchecked exception) Thrown if this attribute set does not support the remove() operation.
Returns: true if this attribute set changed as a result of the call, i.e., the given attribute value had been a member of this attribute set.
/**
     * Removes the specified attribute from this attribute set if
     * present. If {@code attribute} is null, then
     * {@code remove()} does nothing and returns {@code false}.
     *
     * @param attribute Attribute value to be removed from this attribute set.
     *
     * @return  {@code true} if this attribute set changed as a result of the
     *         call, i.e., the given attribute value had been a member of
     *         this attribute set.
     *
     * @throws  UnmodifiableSetException
     *     (unchecked exception) Thrown if this attribute set does not
     *     support the {@code remove()} operation.
     */
    public boolean remove(Attribute attribute) {
        return
            attribute != null &&
            attrMap.remove(attribute.getCategory()) != null;
    }

    
Returns true if this attribute set contains an attribute for the specified category. 
Params:
  • category – whose presence in this attribute set is
           to be tested.
Returns: true if this attribute set contains an attribute value for the specified category.
/**
     * Returns {@code true} if this attribute set contains an
     * attribute for the specified category.
     *
     * @param  category whose presence in this attribute set is
     *            to be tested.
     *
     * @return  {@code true} if this attribute set contains an attribute
     *         value for the specified category.
     */
    public boolean containsKey(Class<?> category) {
        return
            category != null &&
            AttributeSetUtilities.
            verifyAttributeCategory(category, Attribute.class) != null &&
            attrMap.get(category) != null;
    }

    
Returns true if this attribute set contains the given attribute. 
Params:
  • attribute –  value whose presence in this attribute set is
           to be tested.
Returns: true if this attribute set contains the given attribute value.
/**
     * Returns {@code true} if this attribute set contains the given
     * attribute.
     *
     * @param  attribute  value whose presence in this attribute set is
     *            to be tested.
     *
     * @return  {@code true} if this attribute set contains the given
     *      attribute    value.
     */
    public boolean containsValue(Attribute attribute) {
        return
           attribute != null &&
           attribute instanceof Attribute &&
           attribute.equals(attrMap.get(attribute.getCategory()));
    }

    
Adds all of the elements in the specified set to this attribute. The outcome is the same as if the add(Attribute) operation had been applied to this attribute set successively with each element from the specified set. The behavior of the addAll(AttributeSet) operation is unspecified if the specified set is modified while the operation is in progress. 
 If the addAll(AttributeSet) operation throws an exception, the effect on this attribute set's state is implementation dependent; elements from the specified set before the point of the exception may or may not have been added to this attribute set. 
Params:
  • attributes –  whose elements are to be added to this attribute
           set.
Throws:
  • UnmodifiableSetException –  (Unchecked exception) Thrown if this attribute set does not support the addAll(AttributeSet) method.
  • NullPointerException – 
    (Unchecked exception) Thrown if some element in the specified
    set is null, or the set is null.
See Also:
Returns: true if this attribute set changed as a result of the call.
/**
     * Adds all of the elements in the specified set to this attribute.
     * The outcome is the same as if the
     * {@link #add(Attribute) add(Attribute)}
     * operation had been applied to this attribute set successively with
     * each element from the specified set.
     * The behavior of the {@code addAll(AttributeSet)}
     * operation is unspecified if the specified set is modified while
     * the operation is in progress.
     * <P>
     * If the {@code addAll(AttributeSet)} operation throws an exception,
     * the effect on this attribute set's state is implementation dependent;
     * elements from the specified set before the point of the exception may
     * or may not have been added to this attribute set.
     *
     * @param  attributes  whose elements are to be added to this attribute
     *            set.
     *
     * @return  {@code true} if this attribute set changed as a result of the
     *          call.
     *
     * @throws  UnmodifiableSetException
     *    (Unchecked exception) Thrown if this attribute set does not
     *     support the {@code addAll(AttributeSet)} method.
     * @throws  NullPointerException
     *     (Unchecked exception) Thrown if some element in the specified
     *     set is null, or the set is null.
     *
     * @see #add(Attribute)
     */
    public boolean addAll(AttributeSet attributes) {

        Attribute []attrs = attributes.toArray();
        boolean result = false;
        for (int i=0; i<attrs.length; i++) {
            Attribute newValue =
                AttributeSetUtilities.verifyAttributeValue(attrs[i],
                                                           myInterface);
            Object oldValue = attrMap.put(newValue.getCategory(), newValue);
            result = (! newValue.equals(oldValue)) || result;
        }
        return result;
    }

    
Returns the number of attributes in this attribute set. If this attribute set contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE. 
Returns: The number of attributes in this attribute set.
/**
     * Returns the number of attributes in this attribute set. If this
     * attribute set contains more than {@code Integer.MAX_VALUE} elements,
     * returns  {@code Integer.MAX_VALUE}.
     *
     * @return  The number of attributes in this attribute set.
     */
    public int size() {
        return attrMap.size();
    }

    
Returns:the Attributes contained in this set as an array, zero length
if the AttributeSet is empty.
/**
     *
     * @return the Attributes contained in this set as an array, zero length
     * if the AttributeSet is empty.
     */
    public Attribute[] toArray() {
        Attribute []attrs = new Attribute[size()];
        attrMap.values().toArray(attrs);
        return attrs;
    }


    
Removes all attributes from this attribute set.

Throws:
  • UnmodifiableSetException –  (unchecked exception) Thrown if this attribute set does not support the clear() operation.
/**
     * Removes all attributes from this attribute set.
     *
     * @throws  UnmodifiableSetException
     *   (unchecked exception) Thrown if this attribute set does not support
     *     the {@code clear()} operation.
     */
    public void clear() {
        attrMap.clear();
    }

   
Returns true if this attribute set contains no attributes.

Returns:true if this attribute set contains no attributes.
/**
     * Returns true if this attribute set contains no attributes.
     *
     * @return true if this attribute set contains no attributes.
     */
    public boolean isEmpty() {
        return attrMap.isEmpty();
    }

    
Compares the specified object with this attribute set for equality. Returns true if the given object is also an attribute set and the two attribute sets contain the same attribute category-attribute value mappings. This ensures that the equals() method works properly across different implementations of the AttributeSet interface. 
Params:
  • object – to be compared for equality with this attribute set.
Returns: true if the specified object is equal to this attribute set.
/**
     * Compares the specified object with this attribute set for equality.
     * Returns {@code true} if the given object is also an attribute set and
     * the two attribute sets contain the same attribute category-attribute
     * value mappings. This ensures that the
     * {@code equals()} method works properly across different
     * implementations of the AttributeSet interface.
     *
     * @param  object to be compared for equality with this attribute set.
     *
     * @return  {@code true} if the specified object is equal to this
     *       attribute   set.
     */

    public boolean equals(Object object) {
        if (object == null || !(object instanceof AttributeSet)) {
            return false;
        }

        AttributeSet aset = (AttributeSet)object;
        if (aset.size() != size()) {
            return false;
        }

        Attribute[] attrs = toArray();
        for (int i=0;i<attrs.length; i++) {
            if (!aset.containsValue(attrs[i])) {
                return false;
            }
        }
        return true;
    }

    
Returns the hash code value for this attribute set. The hash code of an attribute set is defined to be the sum of the hash codes of each entry in the AttributeSet. This ensures that t1.equals(t2) implies that t1.hashCode()==t2.hashCode() for any two attribute sets t1 and t2, as required by the general contract of Object.hashCode(). 
Returns: The hash code value for this attribute set.
/**
     * Returns the hash code value for this attribute set.
     * The hash code of an attribute set is defined to be the sum
     * of the hash codes of each entry in the AttributeSet.
     * This ensures that {@code t1.equals(t2)} implies that
     * {@code t1.hashCode()==t2.hashCode()} for any two attribute sets
     * {@code t1} and {@code t2}, as required by the general contract of
     * {@link java.lang.Object#hashCode() Object.hashCode()}.
     *
     * @return  The hash code value for this attribute set.
     */
    public int hashCode() {
        int hcode = 0;
        Attribute[] attrs = toArray();
        for (int i=0;i<attrs.length; i++) {
            hcode += attrs[i].hashCode();
        }
        return hcode;
    }

}