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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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
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 * accompanied this code).
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package javax.naming.directory;

import java.util.Hashtable;
import java.util.Enumeration;
import java.util.Locale;

import javax.naming.NamingException;
import javax.naming.NamingEnumeration;


This class provides a basic implementation
of the Attributes interface.


BasicAttributes is either case-sensitive or case-insensitive (case-ignore).
This property is determined at the time the BasicAttributes constructor
is called.
In a case-insensitive BasicAttributes, the case of its attribute identifiers
is ignored when searching for an attribute, or adding attributes.
In a case-sensitive BasicAttributes, the case is significant.


When the BasicAttributes class needs to create an Attribute, it
uses BasicAttribute. There is no other dependency on BasicAttribute.


Note that updates to BasicAttributes (such as adding or removing an attribute)
does not affect the corresponding representation in the directory.
Updates to the directory can only be effected
using operations in the DirContext interface.


A BasicAttributes instance is not synchronized against concurrent
multithreaded access. Multiple threads trying to access and modify
a single BasicAttributes instance should lock the object.

Author:Rosanna Lee, Scott Seligman
See Also:
Since:1.3
/**
  * This class provides a basic implementation
  * of the Attributes interface.
  *<p>
  * BasicAttributes is either case-sensitive or case-insensitive (case-ignore).
  * This property is determined at the time the BasicAttributes constructor
  * is called.
  * In a case-insensitive BasicAttributes, the case of its attribute identifiers
  * is ignored when searching for an attribute, or adding attributes.
  * In a case-sensitive BasicAttributes, the case is significant.
  *<p>
  * When the BasicAttributes class needs to create an Attribute, it
  * uses BasicAttribute. There is no other dependency on BasicAttribute.
  *<p>
  * Note that updates to BasicAttributes (such as adding or removing an attribute)
  * does not affect the corresponding representation in the directory.
  * Updates to the directory can only be effected
  * using operations in the DirContext interface.
  *<p>
  * A BasicAttributes instance is not synchronized against concurrent
  * multithreaded access. Multiple threads trying to access and modify
  * a single BasicAttributes instance should lock the object.
  *
  * @author Rosanna Lee
  * @author Scott Seligman
  *
  * @see DirContext#getAttributes
  * @see DirContext#modifyAttributes
  * @see DirContext#bind
  * @see DirContext#rebind
  * @see DirContext#createSubcontext
  * @see DirContext#search
  * @since 1.3
  */

public class BasicAttributes implements Attributes {
    
Indicates whether case of attribute ids is ignored.

@serial
/**
     * Indicates whether case of attribute ids is ignored.
     * @serial
     */
    private boolean ignoreCase = false;

    // The 'key' in attrs is stored in the 'right case'.
    // If ignoreCase is true, key is aways lowercase.
    // If ignoreCase is false, key is stored as supplied by put().
    // %%% Not declared "private" due to bug 4064984.
    transient Hashtable<String,Attribute> attrs = new Hashtable<>(11);

    
Constructs a new instance of Attributes.
The character case of attribute identifiers
is significant when subsequently retrieving or adding attributes.

/**
      * Constructs a new instance of Attributes.
      * The character case of attribute identifiers
      * is significant when subsequently retrieving or adding attributes.
      */
    public BasicAttributes() {
    }

    
Constructs a new instance of Attributes.
If ignoreCase is true, the character case of attribute
identifiers is ignored; otherwise the case is significant.

Params:
  • ignoreCase – true means this attribute set will ignore
                  the case of its attribute identifiers
                  when retrieving or adding attributes;
                  false means case is respected.
/**
      * Constructs a new instance of Attributes.
      * If <code>ignoreCase</code> is true, the character case of attribute
      * identifiers is ignored; otherwise the case is significant.
      * @param ignoreCase true means this attribute set will ignore
      *                   the case of its attribute identifiers
      *                   when retrieving or adding attributes;
      *                   false means case is respected.
      */
    public BasicAttributes(boolean ignoreCase) {
        this.ignoreCase = ignoreCase;
    }

    
Constructs a new instance of Attributes with one attribute.
The attribute specified by attrID and val are added to the newly
created attribute.
The character case of attribute identifiers
is significant when subsequently retrieving or adding attributes.

Params:
  • attrID –   non-null The id of the attribute to add.
  • val – The value of the attribute to add. If null, a null
       value is added to the attribute.
/**
      * Constructs a new instance of Attributes with one attribute.
      * The attribute specified by attrID and val are added to the newly
      * created attribute.
      * The character case of attribute identifiers
      * is significant when subsequently retrieving or adding attributes.
      * @param attrID   non-null The id of the attribute to add.
      * @param val The value of the attribute to add. If null, a null
      *        value is added to the attribute.
      */
    public BasicAttributes(String attrID, Object val) {
        this();
        this.put(new BasicAttribute(attrID, val));
    }

    
Constructs a new instance of Attributes with one attribute.
The attribute specified by attrID and val are added to the newly
created attribute.
If ignoreCase is true, the character case of attribute
identifiers is ignored; otherwise the case is significant.

Params:
  • attrID –   non-null The id of the attribute to add.
          If this attribute set ignores the character
          case of its attribute ids, the case of attrID
          is ignored.
  • val – The value of the attribute to add. If null, a null
       value is added to the attribute.
  • ignoreCase – true means this attribute set will ignore
                  the case of its attribute identifiers
                  when retrieving or adding attributes;
                  false means case is respected.
/**
      * Constructs a new instance of Attributes with one attribute.
      * The attribute specified by attrID and val are added to the newly
      * created attribute.
      * If <code>ignoreCase</code> is true, the character case of attribute
      * identifiers is ignored; otherwise the case is significant.
      * @param attrID   non-null The id of the attribute to add.
      *           If this attribute set ignores the character
      *           case of its attribute ids, the case of attrID
      *           is ignored.
      * @param val The value of the attribute to add. If null, a null
      *        value is added to the attribute.
      * @param ignoreCase true means this attribute set will ignore
      *                   the case of its attribute identifiers
      *                   when retrieving or adding attributes;
      *                   false means case is respected.
      */
    public BasicAttributes(String attrID, Object val, boolean ignoreCase) {
        this(ignoreCase);
        this.put(new BasicAttribute(attrID, val));
    }

    @SuppressWarnings("unchecked")
    public Object clone() {
        BasicAttributes attrset;
        try {
            attrset = (BasicAttributes)super.clone();
        } catch (CloneNotSupportedException e) {
            attrset = new BasicAttributes(ignoreCase);
        }
        attrset.attrs = (Hashtable<String,Attribute>)attrs.clone();
        return attrset;
    }

    public boolean isCaseIgnored() {
        return ignoreCase;
    }

    public int size() {
        return attrs.size();
    }

    public Attribute get(String attrID) {
        Attribute attr = attrs.get(
                ignoreCase ? attrID.toLowerCase(Locale.ENGLISH) : attrID);
        return (attr);
    }

    public NamingEnumeration<Attribute> getAll() {
        return new AttrEnumImpl();
    }

    public NamingEnumeration<String> getIDs() {
        return new IDEnumImpl();
    }

    public Attribute put(String attrID, Object val) {
        return this.put(new BasicAttribute(attrID, val));
    }

    public Attribute put(Attribute attr) {
        String id = attr.getID();
        if (ignoreCase) {
            id = id.toLowerCase(Locale.ENGLISH);
        }
        return attrs.put(id, attr);
    }

    public Attribute remove(String attrID) {
        String id = (ignoreCase ? attrID.toLowerCase(Locale.ENGLISH) : attrID);
        return attrs.remove(id);
    }

    
Generates the string representation of this attribute set.
The string consists of each attribute identifier and the contents
of each attribute. The contents of this string is useful
for debugging and is not meant to be interpreted programmatically.

Returns:A non-null string listing the contents of this attribute set.
/**
     * Generates the string representation of this attribute set.
     * The string consists of each attribute identifier and the contents
     * of each attribute. The contents of this string is useful
     * for debugging and is not meant to be interpreted programmatically.
     *
     * @return A non-null string listing the contents of this attribute set.
     */
    public String toString() {
        if (attrs.size() == 0) {
            return("No attributes");
        } else {
            return attrs.toString();
        }
    }

    
Determines whether this BasicAttributes is equal to another Attributes Two Attributes are equal if they are both instances of Attributes, treat the case of attribute IDs the same way, and contain the same attributes. Each Attribute in this BasicAttributes is checked for equality using Object.equals(), which may have be overridden by implementations of Attribute). If a subclass overrides equals(), it should override hashCode() as well so that two Attributes instances that are equal have the same hash code. 
Params:
  • obj – the possibly null object to compare against.
See Also:
Returns:true If obj is equal to this BasicAttributes.
/**
     * Determines whether this {@code BasicAttributes} is equal to another
     * {@code Attributes}
     * Two {@code Attributes} are equal if they are both instances of
     * {@code Attributes},
     * treat the case of attribute IDs the same way, and contain the
     * same attributes. Each {@code Attribute} in this {@code BasicAttributes}
     * is checked for equality using {@code Object.equals()}, which may have
     * be overridden by implementations of {@code Attribute}).
     * If a subclass overrides {@code equals()},
     * it should override {@code hashCode()}
     * as well so that two {@code Attributes} instances that are equal
     * have the same hash code.
     * @param obj the possibly null object to compare against.
     *
     * @return true If obj is equal to this BasicAttributes.
     * @see #hashCode
     */
    public boolean equals(Object obj) {
        if ((obj != null) && (obj instanceof Attributes)) {
            Attributes target = (Attributes)obj;

            // Check case first
            if (ignoreCase != target.isCaseIgnored()) {
                return false;
            }

            if (size() == target.size()) {
                Attribute their, mine;
                try {
                    NamingEnumeration<?> theirs = target.getAll();
                    while (theirs.hasMore()) {
                        their = (Attribute)theirs.next();
                        mine = get(their.getID());
                        if (!their.equals(mine)) {
                            return false;
                        }
                    }
                } catch (NamingException e) {
                    return false;
                }
                return true;
            }
        }
        return false;
    }

    
Calculates the hash code of this BasicAttributes.

 The hash code is computed by adding the hash code of the attributes of this object. If this BasicAttributes ignores case of its attribute IDs, one is added to the hash code. If a subclass overrides hashCode(), it should override equals() as well so that two Attributes instances that are equal have the same hash code. 
See Also:
Returns:an int representing the hash code of this BasicAttributes instance.
/**
     * Calculates the hash code of this BasicAttributes.
     *<p>
     * The hash code is computed by adding the hash code of
     * the attributes of this object. If this BasicAttributes
     * ignores case of its attribute IDs, one is added to the hash code.
     * If a subclass overrides {@code hashCode()},
     * it should override {@code equals()}
     * as well so that two {@code Attributes} instances that are equal
     * have the same hash code.
     *
     * @return an int representing the hash code of this BasicAttributes instance.
     * @see #equals
     */
    public int hashCode() {
        int hash = (ignoreCase ? 1 : 0);
        try {
            NamingEnumeration<?> all = getAll();
            while (all.hasMore()) {
                hash += all.next().hashCode();
            }
        } catch (NamingException e) {}
        return hash;
    }

    
Overridden to avoid exposing implementation details.

@serialDataDefault field (ignoreCase flag -- a boolean), followed by
the number of attributes in the set
(an int), and then the individual Attribute objects.
/**
     * Overridden to avoid exposing implementation details.
     * @serialData Default field (ignoreCase flag -- a boolean), followed by
     * the number of attributes in the set
     * (an int), and then the individual Attribute objects.
     */
    private void writeObject(java.io.ObjectOutputStream s)
            throws java.io.IOException {
        s.defaultWriteObject(); // write out the ignoreCase flag
        s.writeInt(attrs.size());
        Enumeration<Attribute> attrEnum = attrs.elements();
        while (attrEnum.hasMoreElements()) {
            s.writeObject(attrEnum.nextElement());
        }
    }

    
Overridden to avoid exposing implementation details.

/**
     * Overridden to avoid exposing implementation details.
     */
    private void readObject(java.io.ObjectInputStream s)
            throws java.io.IOException, ClassNotFoundException {
        s.defaultReadObject();  // read in the ignoreCase flag
        int n = s.readInt();    // number of attributes
        attrs = (n >= 1)
                ? new Hashtable<>(1 + (int) (Math.min(768, n) / .75f))
                : new Hashtable<>(2); // can't have initial size of 0 (grrr...)
        while (--n >= 0) {
            put((Attribute)s.readObject());
        }
    }


class AttrEnumImpl implements NamingEnumeration<Attribute> {

    Enumeration<Attribute> elements;

    public AttrEnumImpl() {
        this.elements = attrs.elements();
    }

    public boolean hasMoreElements() {
        return elements.hasMoreElements();
    }

    public Attribute nextElement() {
        return elements.nextElement();
    }

    public boolean hasMore() throws NamingException {
        return hasMoreElements();
    }

    public Attribute next() throws NamingException {
        return nextElement();
    }

    public void close() throws NamingException {
        elements = null;
    }
}

class IDEnumImpl implements NamingEnumeration<String> {

    Enumeration<Attribute> elements;

    public IDEnumImpl() {
        // Walking through the elements, rather than the keys, gives
        // us attribute IDs that have not been converted to lowercase.
        this.elements = attrs.elements();
    }

    public boolean hasMoreElements() {
        return elements.hasMoreElements();
    }

    public String nextElement() {
        Attribute attr = elements.nextElement();
        return attr.getID();
    }

    public boolean hasMore() throws NamingException {
        return hasMoreElements();
    }

    public String next() throws NamingException {
        return nextElement();
    }

    public void close() throws NamingException {
        elements = null;
    }
}

    
Use serialVersionUID from JNDI 1.1.1 for interoperability.

/**
     * Use serialVersionUID from JNDI 1.1.1 for interoperability.
     */
    private static final long serialVersionUID = 4980164073184639448L;
}