org.openmdx.base.collection.NullMaskingMap Maven / Gradle / Ivy
/*
* ====================================================================
* Project: openMDX, http://www.openmdx.org/
* Description: Null Masking Map
* Owner: OMEX AG, Switzerland, http://www.omex.ch
* ====================================================================
*
* This software is published under the BSD license as listed below.
*
* Copyright (c) 2008, OMEX AG, Switzerland
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of the openMDX team nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ------------------
*
* This product includes software developed by other organizations as
* listed in the NOTICE file.
*/
package org.openmdx.base.collection;
import java.util.AbstractCollection;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/**
* NullMaskingMap
*
*/
@SuppressWarnings("rawtypes")
class NullMaskingMap extends AbstractMapDecorator {
/**
* Constructor only used in deserialization, do not use otherwise.
*/
protected NullMaskingMap() {
super();
}
/**
* Constructor
*
* @param map
*/
protected NullMaskingMap(
Map delegate,
Object nullValue
) {
super(delegate);
this.nullValue = nullValue;
}
/**
* The null value object
*/
Object nullValue;
/**
* The values
*/
private transient Collection values;
/**
* The entry set
*/
private transient Set entries;
/**
* Decorate a given map
*
* @param delegate
* @param nullValue
*
* @return a newly created decorated map
*/
static Map decorate(
Map delegate,
Object nullValue
){
return new NullMaskingMap(delegate, nullValue);
}
@Override
public boolean containsValue(Object value) {
return super.containsValue(
mask(value)
);
}
@Override
public Set entrySet() {
if(this.entries == null) {
this.entries = new Entries(
super.entrySet()
);
}
return this.entries;
}
@Override
public Object get(Object key) {
return unmask(
super.get(key)
);
}
@Override
public Object put(Object key, Object value) {
return super.put(
key,
mask(value)
);
}
@SuppressWarnings("unchecked")
@Override
public void putAll(Map mapToCopy) {
for (Map.Entry e : (Set>) super.entrySet()) {
super.put(
e.getKey(),
mask(e.getValue())
);
}
}
@Override
public Collection values() {
if(this.values == null) {
this.values = new Values(super.values());
}
return this.values;
}
/**
* Replace null by nullValue
*
* @param value
*
* @return the masked value
*/
protected Object mask (
Object value
){
return value == null ? this.nullValue : value;
}
/**
* Replace null by null
*
* @param value
*
* @return the unmasked value
*/
protected Object unmask (
Object value
){
return value == this.nullValue ? null : value;
}
//------------------------------------------------------------------------
// Class MaskedValues
//------------------------------------------------------------------------
/**
* Masked Values
*/
class Values extends AbstractCollection {
/**
* Constructor
*
* @param delegate
* @param nullValue
*/
Values(
Collection delegate
){
this.delegate = delegate;
}
/**
* Non-masked values
*/
protected final Collection delegate;
/* (non-Javadoc)
* @see java.util.AbstractCollection#iterator()
*/
@Override
public Iterator iterator() {
return new Iterator() {
private final Iterator delegate = Values.this.delegate.iterator();
public boolean hasNext() {
return this.delegate.hasNext();
}
public Object next() {
return unmask(this.delegate.next());
}
public void remove() {
this.delegate.remove();
}
};
}
/* (non-Javadoc)
* @see java.util.AbstractCollection#size()
*/
@Override
public int size() {
return this.delegate.size();
}
/* (non-Javadoc)
* @see java.util.AbstractCollection#isEmpty()
*/
@Override
public boolean isEmpty() {
return this.delegate.isEmpty();
}
}
//------------------------------------------------------------------------
// Class MaskedEntries
//------------------------------------------------------------------------
/**
* Masked Entries
*/
class Entries extends AbstractSet {
/**
* Constructor
*
* @param delegate
*/
Entries(
Set delegate
){
this.delegate = delegate;
}
/**
*
*/
protected final Set delegate;
/* (non-Javadoc)
* @see java.util.AbstractCollection#iterator()
*/
@Override
public Iterator iterator() {
return new Iterator() {
protected final Iterator delegate = Entries.this.delegate.iterator();
public boolean hasNext() {
return this.delegate.hasNext();
}
public Object next() {
return new Map.Entry(){
private final Map.Entry entry = (Entry) delegate.next();
public Object getKey() {
return entry.getKey();
}
public Object getValue() {
return unmask(entry.getValue());
}
@SuppressWarnings("unchecked")
public Object setValue(Object value) {
return unmask(
entry.setValue(
mask(value)
)
);
}
};
}
public void remove() {
this.delegate.remove();
}
};
}
/* (non-Javadoc)
* @see java.util.AbstractCollection#size()
*/
@Override
public int size() {
return this.delegate.size();
}
/* (non-Javadoc)
* @see java.util.AbstractCollection#isEmpty()
*/
@Override
public boolean isEmpty() {
return this.delegate.isEmpty();
}
}
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