/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2007-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*/
package org.geotools.metadata;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import org.geotools.util.Utilities;
/**
* A view of a metadata object as a map. Keys are property names and values
* are the value returned by the {@code getFoo()} method using reflection.
*
* @since 2.4
* @source $URL$
* @version $Id$
* @author Martin Desruisseaux (Geomatys)
*
* @see MetadataStandard#asMap
*/
final class PropertyMap extends AbstractMap<String,Object> {
/**
* The metadata object to wrap.
*/
private final Object metadata;
/**
* The accessor to use for the metadata.
*/
private final PropertyAccessor accessor;
/**
* A view of the mappings contained in this map.
*/
private final Set<Map.Entry<String,Object>> entrySet;
/**
* Creates a property map for the specified metadata and accessor.
*/
public PropertyMap(final Object metadata, final PropertyAccessor accessor) {
this.metadata = metadata;
this.accessor = accessor;
entrySet = new Entries();
}
/**
* Returns {@code true} if this map contains no key-value mappings.
*/
@Override
public boolean isEmpty() {
return entrySet().isEmpty();
}
/**
* Returns {@code true} if this map contains a mapping for the specified key.
*/
@Override
public boolean containsKey(final Object key) {
return get(key) != null;
}
/**
* Returns the value to which the specified key is mapped, or {@code null}
* if this map contains no mapping for the key.
*/
@Override
public Object get(final Object key) {
if (key instanceof String) {
final Object value = accessor.get(accessor.indexOf((String) key), metadata);
if (!PropertyAccessor.isEmpty(value)) {
return value;
}
}
return null;
}
/**
* Associates the specified value with the specified key in this map.
*
* @throws IllegalArgumentException if the specified property can't be set.
* @throws ClassCastException if the given value is not of the expected type.
*/
@Override
public Object put(final String key, final Object value)
throws IllegalArgumentException, ClassCastException
{
return accessor.set(accessor.requiredIndexOf(key), metadata, value);
}
/**
* Removes the mapping for a key from this map if it is present.
*/
@Override
public Object remove(final Object key) {
if (key instanceof String) {
return put((String) key, null);
} else {
return null;
}
}
/**
* Returns a view of the mappings contained in this map.
*/
@Override
public Set<Map.Entry<String,Object>> entrySet() {
return entrySet;
}
/**
* A map entry for a given property.
*
* @author Martin Desruisseaux
*/
private final class Property implements Map.Entry<String,Object> {
/**
* The property index.
*/
final int index;
/**
* Creates an entry for the given property.
*/
Property(final int index) {
this.index = index;
}
/**
* Creates an entry for the given property.
*/
Property(final String property) {
index = accessor.indexOf(property);
}
/**
* Returns the key corresponding to this entry.
*/
public String getKey() {
return accessor.name(index);
}
/**
* Returns the value corresponding to this entry.
*/
public Object getValue() {
final Object value = accessor.get(index, metadata);
return PropertyAccessor.isEmpty(value) ? null : value;
}
/**
* Replaces the value corresponding to this entry with the specified value.
*
* @throws ClassCastException if the given value is not of the expected type.
*/
public Object setValue(Object value) throws ClassCastException {
return accessor.set(index, metadata, value);
}
/**
* Compares the specified entry with this one for equality.
*/
public boolean equals(final Map.Entry<?,?> entry) {
return Utilities.equals(getKey(), entry.getKey()) &&
Utilities.equals(getValue(), entry.getValue());
}
/**
* Compares the specified object with this entry for equality.
* Criterions are specified by the {@link Map.Entry} contract.
*/
@Override
public boolean equals(final Object object) {
return (object instanceof Map.Entry) && equals((Map.Entry) object);
}
/**
* Returns the hash code value for this map entry. The
* formula is specified by the {@link Map.Entry} contract.
*/
@Override
public int hashCode() {
Object x = getKey();
int code = (x != null) ? x.hashCode() : 0;
x = getValue();
if (x != null) {
code ^= x.hashCode();
}
return code;
}
}
/**
* The iterator over the {@link Property} elements contained in a {@link Entries} set.
*
* @author Martin Desruisseaux
*/
private final class Iter implements Iterator<Map.Entry<String,Object>> {
/**
* The current and the next property, or {@code null} if the iteration is over.
*/
private Property current, next;
/**
* Creates en iterator.
*/
Iter() {
move(0);
}
/**
* Move {@link #next} to the first property with a valid value,
* starting at the specified index.
*/
private void move(int index) {
final int count = accessor.count();
while (index < count) {
if (!PropertyAccessor.isEmpty(accessor.get(index, metadata))) {
next = new Property(index);
return;
}
index++;
}
next = null;
}
/**
* Returns {@code true} if the iteration has more elements.
*/
public boolean hasNext() {
return next != null;
}
/**
* Returns the next element in the iteration.
*/
public Map.Entry<String,Object> next() {
if (next != null) {
current = next;
move(next.index + 1);
return current;
} else {
throw new NoSuchElementException();
}
}
/**
* Removes from the underlying collection the last element returned by the iterator.
*/
public void remove() {
if (current != null) {
current.setValue(null);
current = null;
} else {
throw new IllegalStateException();
}
}
}
/**
* View of the mapping contained in the map.
*
* @author Martin Desruisseaux
*/
private final class Entries extends AbstractSet<Map.Entry<String,Object>> {
/**
* Creates an entry set.
*/
Entries() {
}
/**
* Returns an iterator over the elements contained in this collection.
*/
@Override
public Iterator<Map.Entry<String,Object>> iterator() {
return new Iter();
}
/**
* Returns the number of elements in this collection.
*/
public int size() {
return accessor.count(metadata, Integer.MAX_VALUE);
}
/**
* Returns true if this collection contains no elements.
*/
@Override
public boolean isEmpty() {
return accessor.count(metadata, 1) == 0;
}
/**
* Returns {@code true} if this collection contains the specified element.
*/
@Override
public boolean contains(final Object object) {
if (object instanceof Map.Entry) {
final Map.Entry entry = (Map.Entry) object;
final Object key = entry.getKey();
if (key instanceof String) {
return new Property((String) key).equals(entry);
}
}
return false;
}
}
}