org.jdom2.AttributeList Maven / Gradle / Ivy
/*--
Copyright (C) 2000-2012 Jason Hunter & Brett McLaughlin.
All rights reserved.
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modification, are permitted provided that the following conditions
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4. Products derived from this software may not be called "JDOM", nor
may "JDOM" appear in their name, without prior written permission
from the JDOM Project Management .
In addition, we request (but do not require) that you include in the
end-user documentation provided with the redistribution and/or in the
software itself an acknowledgement equivalent to the following:
"This product includes software developed by the
JDOM Project (http://www.jdom.org/)."
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SUCH DAMAGE.
This software consists of voluntary contributions made by many
individuals on behalf of the JDOM Project and was originally
created by Jason Hunter and
Brett McLaughlin . For more information
on the JDOM Project, please see AttributeList represents legal JDOM
* {@link Attribute} content.
*
* This class is NOT PUBLIC; users should see it as a simple List
* implementation, although it behaves something like a Set because you cannot
* add duplicate Attributes. An attribute is considered duplicate if it has the
* same Namespace URI and Attribute name as another existing Attribute.
*
* @author Alex Rosen
* @author Philippe Riand
* @author Bradley S. Huffman
* @author Rolf Lear
*/
final class AttributeList extends AbstractList
implements RandomAccess {
/** The initial size to start the backing array. */
private static final int INITIAL_ARRAY_SIZE = 4;
/** The backing array */
private Attribute attributeData[];
/** The current size */
private int size;
/** The parent Element */
private final Element parent;
private static final Comparator ATTRIBUTE_NATURAL = new Comparator() {
@Override
public int compare(Attribute a1, Attribute a2) {
int pcomp = a1.getNamespacePrefix().compareTo(a2.getNamespacePrefix());
if (pcomp != 0) {
return pcomp;
}
return a1.getName().compareTo(a2.getName());
}
};
/**
* Create a new instance of the AttributeList representing parent
* Element's Attributes
*
* @param parent
* Element whose Attributes are to be held
*/
AttributeList(final Element parent) {
this.parent = parent;
}
/**
* Package internal method to support building from sources that are 100%
* trusted.
*
* @param a
* an Attribute to add without any checks
*/
final void uncheckedAddAttribute(final Attribute a) {
a.parent = parent;
ensureCapacity(size + 1);
attributeData[size++] = a;
modCount++;
}
/**
* Check and add attribute to the end of the list or replace an
* existing Attribute with the same name and
* Namespace.
*
* @param attribute
* The Attribute to insert into the list.
* @return true as specified by Collection.add().
* @throws IllegalAddException
* if validation rules prevent the add
*/
@Override
public boolean add(final Attribute attribute) {
if (attribute.getParent() != null) {
throw new IllegalAddException(
"The attribute already has an existing parent \""
+ attribute.getParent().getQualifiedName() + "\"");
}
if (Verifier.checkNamespaceCollision(attribute, parent) != null) {
throw new IllegalAddException(parent, attribute,
Verifier.checkNamespaceCollision(attribute, parent));
}
// returns -1 if not exist
final int duplicate = indexOfDuplicate(attribute);
if (duplicate < 0) {
attribute.setParent(parent);
ensureCapacity(size + 1);
attributeData[size++] = attribute;
modCount++;
} else {
final Attribute old = attributeData[duplicate];
old.setParent(null);
attributeData[duplicate] = attribute;
attribute.setParent(parent);
}
return true;
}
/**
* Check and add attribute to this list at index.
*
* @param index
* where to add/insert the Attribute
* @param attribute
* Attribute to add
* @throws IllegalAddException
* if validation rules prevent the add
*/
@Override
public void add(final int index, final Attribute attribute) {
if (index < 0 || index > size) {
throw new IndexOutOfBoundsException("Index: " + index +
" Size: " + size());
}
if (attribute.getParent() != null) {
throw new IllegalAddException(
"The attribute already has an existing parent \"" +
attribute.getParent().getQualifiedName() + "\"");
}
final int duplicate = indexOfDuplicate(attribute);
if (duplicate >= 0) {
throw new IllegalAddException("Cannot add duplicate attribute");
}
final String reason = Verifier.checkNamespaceCollision(attribute, parent);
if (reason != null) {
throw new IllegalAddException(parent, attribute, reason);
}
attribute.setParent(parent);
ensureCapacity(size + 1);
if (index == size) {
attributeData[size++] = attribute;
} else {
System.arraycopy(attributeData, index, attributeData, index + 1,
size - index);
attributeData[index] = attribute;
size++;
}
modCount++;
}
/**
* Add all the Attributes in collection.
*
* @param collection
* The Collection of Attributes to add.
* @return true if the list was modified as a result of the
* add.
* @throws IllegalAddException
* if validation rules prevent the addAll
*/
@Override
public boolean addAll(final Collection collection) {
return addAll(size(), collection);
}
/**
* Inserts the Attributes in collection at the specified
* index in this list.
*
* @param index
* The offset at which to start adding the Attributes
* @param collection
* The Collection containing the Attributes
* to add.
* @return true if the list was modified as a result of the
* add.
* @throws IllegalAddException
* if validation rules prevent the addAll
*/
@Override
public boolean addAll(final int index,
final Collection collection) {
if (index < 0 || index > size) {
throw new IndexOutOfBoundsException("Index: " + index +
" Size: " + size());
}
if (collection == null) {
throw new NullPointerException(
"Can not add a null Collection to AttributeList");
}
final int addcnt = collection.size();
if (addcnt == 0) {
return false;
}
if (addcnt == 1) {
// quick check for single-add.
add(index, collection.iterator().next());
return true;
}
ensureCapacity(size() + addcnt);
final int tmpmodcount = modCount;
boolean ok = false;
int count = 0;
try {
for (Attribute att : collection) {
add(index + count, att);
count++;
}
ok = true;
} finally {
if (!ok) {
while (--count >= 0) {
remove(index + count);
}
modCount = tmpmodcount;
}
}
return true;
}
/**
* Clear the current list.
*/
@Override
public void clear() {
if (attributeData != null) {
while (size > 0) {
size--;
attributeData[size].setParent(null);
attributeData[size] = null;
}
}
modCount++;
}
/**
* Clear the current list and set it to the contents of collection.
*
* @param collection
* The Collection to use.
* @throws IllegalAddException
* if validation rules prevent the addAll
*/
void clearAndSet(final Collection collection) {
if (collection == null || collection.isEmpty()) {
clear();
return;
}
// keep a backup in case we need to roll-back...
final Attribute[] old = attributeData;
final int oldSize = size;
final int oldModCount = modCount;
// clear the current system
// we need to detatch before we add so that we don't run in to a problem
// where an attribute in the to-add list is one that we are 'clearing'
// first.
while (size > 0) {
old[--size].setParent(null);
}
size = 0;
attributeData = null;
boolean ok = false;
try {
addAll(0, collection);
ok = true;
} finally {
if (!ok) {
// we have an exception pending....
// restore the old system.
// re-attach the old stuff
attributeData = old;
while (size < oldSize) {
attributeData[size++].setParent(parent);
}
modCount = oldModCount;
}
}
}
/**
* Increases the capacity of this AttributeList instance, if
* necessary, to ensure that it can hold at least the number of items
* specified by the minimum capacity argument.
*
* @param minCapacity
* the desired minimum capacity.
*/
private void ensureCapacity(final int minCapacity) {
if (attributeData == null) {
attributeData =
new Attribute[Math.max(minCapacity, INITIAL_ARRAY_SIZE)];
return;
} else if (minCapacity < attributeData.length) {
return;
}
// most JVM's allocate memory in multiples of 'double-words', on
// 64-bit it's 16-bytes, on 32-bit it's 8 bytes which all means it makes
// sense to increment the capacity in even values.
attributeData = ArrayCopy.copyOf(attributeData,
((minCapacity + INITIAL_ARRAY_SIZE) >>> 1) << 1);
}
/**
* Retrieve the Attribute at offset.
*
* @param index
* The position of the Attribute to retrieve.
* @return The Attribute at position index.
*/
@Override
public Attribute get(final int index) {
if (index < 0 || index >= size) {
throw new IndexOutOfBoundsException("Index: " + index +
" Size: " + size());
}
return attributeData[index];
}
/**
* Retrieve the Attribute with the given name and the same
* Namespace URI as namespace.
*
* @param name
* name of attribute to return
* @param namespace
* indicate what Namespace URI to consider
* @return the Attribute, or null if one doesn't exist.
*/
Attribute get(final String name, final Namespace namespace) {
final int index = indexOf(name, namespace);
if (index < 0) {
return null;
}
return attributeData[index];
}
/**
* Return index of the Attribute with the given name and
* the same Namespace URI as namespace.
*
* @param name
* name of Attribute to retrieve
* @param namespace
* indicate what Namespace URI to consider
* @return the index of the attribute that matches the conditions, or
* -1 if there is none.
*/
int indexOf(final String name, final Namespace namespace) {
if (attributeData != null) {
if (namespace == null) {
return indexOf(name, Namespace.NO_NAMESPACE);
}
final String uri = namespace.getURI();
for (int i = 0; i < size; i++) {
final Attribute att = attributeData[i];
if (uri.equals(att.getNamespaceURI()) &&
name.equals(att.getName())) {
return i;
}
}
}
return -1;
}
/**
* Remove the Attribute at index.
*
* @param index
* The offset of the Attribute to remove.
* @return The removed Attribute.
*/
@Override
public Attribute remove(final int index) {
if (index < 0 || index >= size)
throw new IndexOutOfBoundsException("Index: " + index +
" Size: " + size());
final Attribute old = attributeData[index];
old.setParent(null);
System.arraycopy(attributeData, index + 1, attributeData, index,
size - index - 1);
attributeData[--size] = null; // Let gc do its work
modCount++;
return old;
}
/**
* Remove the Attribute with the specified name and the same
* URI as namespace.
*
* @param name
* name of Attribute to remove
* @param namespace
* indicate what Namespace URI to consider
* @return the true if attribute was removed,
* false otherwise
*/
boolean remove(final String name, final Namespace namespace) {
final int index = indexOf(name, namespace);
if (index < 0) {
return false;
}
remove(index);
return true;
}
/**
* Set the Attribute at index to be attribute.
*
* @param index
* The location to set the value to.
* @param attribute
* The Attribute to set.
* @return The replaced Attribute.
* @throws IllegalAddException
* if validation rules prevent the set
*/
@Override
public Attribute set(final int index, final Attribute attribute) {
if (index < 0 || index >= size)
throw new IndexOutOfBoundsException("Index: " + index +
" Size: " + size());
if (attribute.getParent() != null) {
throw new IllegalAddException(
"The attribute already has an existing parent \"" +
attribute.getParent().getQualifiedName() + "\"");
}
final int duplicate = indexOfDuplicate(attribute);
if ((duplicate >= 0) && (duplicate != index)) {
throw new IllegalAddException("Cannot set duplicate attribute");
}
final String reason = Verifier.checkNamespaceCollision(attribute, parent, index);
if (reason != null) {
throw new IllegalAddException(parent, attribute, reason);
}
final Attribute old = attributeData[index];
old.setParent(null);
attributeData[index] = attribute;
attribute.setParent(parent);
return old;
}
/**
* Return index of attribute with same name and Namespace, or -1 if one
* doesn't exist
*/
private int indexOfDuplicate(final Attribute attribute) {
return indexOf(attribute.getName(), attribute.getNamespace());
}
/**
* Returns an Iterator over the Attributes in this
* list in the proper sequence.
*
* @return an iterator.
*/
@Override
public Iterator iterator() {
return new ALIterator();
}
/**
* Return the number of Attributes in this list
*
* @return The number of Attributes in this list.
*/
@Override
public int size() {
return size;
}
@Override
public boolean isEmpty() {
return size == 0;
}
/**
* Return this list as a String
*/
@Override
public String toString() {
return super.toString();
}
/**
* Unlike the Arrays.binarySearch, this method never expects an
* "already exists" condition, we only ever add, thus there will never
* be a negative insertion-point.
* @param indexes The pointers to search within
* @param len The number of pointers to search within
* @param val The pointer we are checking for.
* @param comp The Comparator to compare with
* @return the insertion point.
*/
private final int binarySearch(final int[] indexes, final int len,
final int val, final Comparator comp) {
int left = 0, mid = 0, right = len - 1, cmp = 0;
final Attribute base = attributeData[val];
while (left <= right) {
mid = (left + right) >>> 1;
cmp = comp.compare(base, attributeData[indexes[mid]]);
if (cmp == 0) {
while (cmp == 0 && mid < right && comp.compare(
base, attributeData[indexes[mid + 1]]) == 0) {
mid++;
}
return mid + 1;
} else if (cmp < 0) {
right = mid - 1;
} else {
left = mid + 1;
}
}
return left;
}
private void sortInPlace(final int[] indexes) {
// the indexes are a discrete set of values that have no duplicates,
// and describe the relative order of each of them.
// as a result, we can do some tricks....
final int[] unsorted = ArrayCopy.copyOf(indexes, indexes.length);
Arrays.sort(unsorted);
final Attribute[] usc = new Attribute[unsorted.length];
for (int i = 0; i < usc.length; i++) {
usc[i] = attributeData[indexes[i]];
}
// usc contains the content in their pre-sorted order....
for (int i = 0; i < indexes.length; i ++) {
attributeData[unsorted[i]] = usc[i];
}
}
/**
* Sort the attributes using the supplied comparator. The attributes are
* never added using regular mechanisms, so there are never problems with
* detached or already-attached Attributes. The sort happens 'in place'.
*
* If the comparator identifies two (or more) Attributes to be equal, then
* the relative order of those attributes will not be changed.
*
* @param comp The Comparator to use for sorting.
*/
public void sort(Comparator comp) {
if (comp == null) {
comp = ATTRIBUTE_NATURAL;
}
final int sz = size;
int[] indexes = new int[sz];
for (int i = 0 ; i < sz; i++) {
final int ip = binarySearch(indexes, i, i, comp);
if (ip < i) {
System.arraycopy(indexes, ip, indexes, ip+1, i - ip);
}
indexes[ip] = i;
}
sortInPlace(indexes);
}
/* * * * * * * * * * * * * ContentListIterator * * * * * * * * * * * * * */
/* * * * * * * * * * * * * ContentListIterator * * * * * * * * * * * * * */
/**
* A fast iterator that can beat AbstractList because we can access the data
* directly. This is important because so much code now uses the for-each
* type loop for (Attribute a : element.getAttributes()) {...},
* and that uses iterator().
*
* @author Rolf Lear
*/
private final class ALIterator implements Iterator {
// The modCount to expect (or throw ConcurrentModeEx)
private int expect = -1;
// the index of the next Attribute to return.
private int cursor = 0;
// whether it is legal to call remove()
private boolean canremove = false;
private ALIterator() {
expect = modCount;
}
@Override
public boolean hasNext() {
return cursor < size;
}
@Override
public Attribute next() {
if (modCount != expect) {
throw new ConcurrentModificationException("ContentList was " +
"modified outside of this Iterator");
}
if (cursor >= size) {
throw new NoSuchElementException("Iterated beyond the end of " +
"the ContentList.");
}
canremove = true;
return attributeData[cursor++];
}
@Override
public void remove() {
if (modCount != expect) {
throw new ConcurrentModificationException("ContentList was " +
"modified outside of this Iterator");
}
if (!canremove) {
throw new IllegalStateException("Can only remove() content " +
"after a call to next()");
}
AttributeList.this.remove(--cursor);
expect = modCount;
canremove = false;
}
}
}