A generic bag of properties used to store properties that apply to a specific target.
/*
* XAdES4j - A Java library for generation and verification of XAdES signatures.
* Copyright (C) 2010 Luis Goncalves.
*
* XAdES4j 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; either version 3 of the License, or any later version.
*
* XAdES4j 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.
*
* You should have received a copy of the GNU Lesser General Public License along
* with XAdES4j. If not, see <http://www.gnu.org/licenses/>.
*/
//package xades4j.utils;
//import xades4j.properties.PropertyTargetException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* A generic bag of properties used to store properties that apply to a specific
* target (data object descriptions, signature properties collector, signed data
* objects). The properties are organized by type (class).
*
* @author Lus
*/
public class PropertiesSet<T>
{
private final Map<Class, Set<T>> properties;
/**
* Initializes the property bag with the given initial diferent property types.
* @param initialNPropTypes the initial number of different property types.
*/
public PropertiesSet(int initialNPropTypes)
{
this.properties = new HashMap<Class, Set<T>>(initialNPropTypes);
}
/**
* Puts a property in the bag. The put operation doesn't allow repeated
* property types. If a property of this type was previously added an exception
* is thrown.
*
* @param prop the property
*
* @throws NullPointerException if {@code prop} is {@code null}
* @throws PropertyTargetException if a property of this type was previously
* added
*/
public void put(T prop)
{
if (null == prop)
throw new NullPointerException("Property cannot be null");
// If an entry for the property's type is already present it means that a
// property of this type was previously added. Adding another property of
// this type is not allowed.
if (properties.containsKey(prop.getClass()))
throw new Exception(String.format("A property of type %s was already added", prop.getClass().getSimpleName()));
add(prop);
}
/**
* Adds a property to the bag. The add operation allows multiple properties
* of the same type but not repeated instances.
* @param prop the property
*
* @throws NullPointerException if {@code prop} is {@code null}
* @throws PropertyTargetException if the given property (instance)
* is already present in the bag
*/
public void add(T prop)
{
if (null == prop)
throw new NullPointerException("Property cannot be null");
Set<T> propsOfCurrType = properties.get(prop.getClass());
if (null == propsOfCurrType)
{
// No properties of this type have been added.
propsOfCurrType = new HashSet<T>(1);
properties.put(prop.getClass(), propsOfCurrType);
}
// Repeated instances are not allowed.
if (!propsOfCurrType.add(prop))
throw new Exception("Property instance already present");
}
/**
* Removes a property from the bag.
*
* @param prop the property to be removed
*
* @throws NullPointerException if the property is {@code null}
* @throws IllegalStateException if the property is not present
*/
public void remove(T prop)
{
if (null == prop)
throw new NullPointerException("Property cannot be null");
Set<T> propsOfCurrType = properties.get(prop.getClass());
if (null == propsOfCurrType || !propsOfCurrType.remove(prop))
throw new IllegalStateException("Property not present");
if (propsOfCurrType.isEmpty())
properties.remove(prop.getClass());
}
/**
* Indicates whether the bag has any properties.
* @return {@code true} if the bag has no properties
*/
public boolean isEmpty()
{
// If any entry for any property type is present, then at least one
// property was specified.
return properties.isEmpty();
}
/**
* Gets the properties in the bag.
* @return un unmodifiable collection of properties
*/
public Collection<T> getProperties()
{
if (properties.isEmpty())
return Collections.emptyList();
Collection<T> props = new ArrayList<T>(properties.size() + 3);
for (Set<T> propsOfType : properties.values())
{
props.addAll(propsOfType);
}
return props;
}
}
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