rs.mail.templates.cache.Cache Maven / Gradle / Ivy
package rs.mail.templates.cache;
import java.util.Collection;
import java.util.Set;
/**
* A simple definition of a cache.
* @author ralph
*
*/
public interface Cache {
/**
* Returns the number of key-value mappings in this map. If the
* map contains more than {@code Integer.MAX_VALUE} elements, returns
* {@code Integer.MAX_VALUE}.
*
* @return the number of key-value mappings in this map
*/
int size();
/**
* Returns {@code true} if this map contains no key-value mappings.
*
* @return {@code true} if this map contains no key-value mappings
*/
boolean isEmpty();
/**
* Returns {@code true} if this map contains a mapping for the specified
* key. More formally, returns {@code true} if and only if
* this map contains a mapping for a key {@code k} such that
* {@code (key==null ? k==null : key.equals(k))}. (There can be
* at most one such mapping.)
*
* @param key key whose presence in this map is to be tested
* @return {@code true} if this map contains a mapping for the specified
* key
* @throws ClassCastException if the key is of an inappropriate type for
* this map (optional)
* @throws NullPointerException if the specified key is null and this map
* does not permit null keys (optional)
*/
boolean containsKey(K key);
/**
* Returns {@code true} if this map maps one or more keys to the
* specified value. More formally, returns {@code true} if and only if
* this map contains at least one mapping to a value {@code v} such that
* {@code (value==null ? v==null : value.equals(v))}. This operation
* will probably require time linear in the map size for most
* implementations of the {@code Map} interface.
*
* @param value value whose presence in this map is to be tested
* @return {@code true} if this map maps one or more keys to the
* specified value
* @throws ClassCastException if the value is of an inappropriate type for
* this map (optional)
* @throws NullPointerException if the specified value is null and this
* map does not permit null values (optional)
*/
boolean containsValue(V value);
/**
* Returns the value to which the specified key is mapped,
* or {@code null} if this map contains no mapping for the key.
*
* More formally, if this map contains a mapping from a key
* {@code k} to a value {@code v} such that {@code (key==null ? k==null :
* key.equals(k))}, then this method returns {@code v}; otherwise
* it returns {@code null}. (There can be at most one such mapping.)
*
*
If this map permits null values, then a return value of
* {@code null} does not necessarily indicate that the map
* contains no mapping for the key; it's also possible that the map
* explicitly maps the key to {@code null}. The {@link #containsKey
* containsKey} operation may be used to distinguish these two cases.
*
* @param key the key whose associated value is to be returned
* @return the value to which the specified key is mapped, or
* {@code null} if this map contains no mapping for the key
* @throws ClassCastException if the key is of an inappropriate type for
* this map (optional)
* @throws NullPointerException if the specified key is null and this map
* does not permit null keys (optional)
*/
V get(K key);
// Modification Operations
/**
* Associates the specified value with the specified key in this map
* (optional operation). If the map previously contained a mapping for
* the key, the old value is replaced by the specified value. (A map
* {@code m} is said to contain a mapping for a key {@code k} if and only
* if {@link #containsKey(Object) m.containsKey(k)} would return
* {@code true}.)
*
* @param key key with which the specified value is to be associated
* @param value value to be associated with the specified key
* @return the previous value associated with {@code key}, or
* {@code null} if there was no mapping for {@code key}.
* (A {@code null} return can also indicate that the map
* previously associated {@code null} with {@code key},
* if the implementation supports {@code null} values.)
* @throws UnsupportedOperationException if the {@code put} operation
* is not supported by this map
* @throws ClassCastException if the class of the specified key or value
* prevents it from being stored in this map
* @throws NullPointerException if the specified key or value is null
* and this map does not permit null keys or values
* @throws IllegalArgumentException if some property of the specified key
* or value prevents it from being stored in this map
*/
V put(K key, V value);
/**
* Removes the mapping for a key from this map if it is present
* (optional operation). More formally, if this map contains a mapping
* from key {@code k} to value {@code v} such that
* (key==null ? k==null : key.equals(k)), that mapping
* is removed. (The map can contain at most one such mapping.)
*
*
Returns the value to which this map previously associated the key,
* or {@code null} if the map contained no mapping for the key.
*
*
If this map permits null values, then a return value of
* {@code null} does not necessarily indicate that the map
* contained no mapping for the key; it's also possible that the map
* explicitly mapped the key to {@code null}.
*
*
The map will not contain a mapping for the specified key once the
* call returns.
*
* @param key key whose mapping is to be removed from the map
* @return the previous value associated with {@code key}, or
* {@code null} if there was no mapping for {@code key}.
* @throws UnsupportedOperationException if the {@code remove} operation
* is not supported by this map
* @throws ClassCastException if the key is of an inappropriate type for
* this map (optional)
* @throws NullPointerException if the specified key is null and this
* map does not permit null keys (optional)
*/
V remove(K key);
/**
* Removes all of the mappings from this map (optional operation).
* The map will be empty after this call returns.
*
* @throws UnsupportedOperationException if the {@code clear} operation
* is not supported by this map
*/
void clear();
/**
* Returns a {@link Set} view of the keys contained in this map.
* The set is backed by the map, so changes to the map are
* reflected in the set, and vice-versa. If the map is modified
* while an iteration over the set is in progress (except through
* the iterator's own {@code remove} operation), the results of
* the iteration are undefined. The set supports element removal,
* which removes the corresponding mapping from the map, via the
* {@code Iterator.remove}, {@code Set.remove},
* {@code removeAll}, {@code retainAll}, and {@code clear}
* operations. It does not support the {@code add} or {@code addAll}
* operations.
*
* @return a set view of the keys contained in this map
*/
Set keySet();
/**
* Returns a {@link Collection} view of the values contained in this map.
* The collection is backed by the map, so changes to the map are
* reflected in the collection, and vice-versa. If the map is
* modified while an iteration over the collection is in progress
* (except through the iterator's own {@code remove} operation),
* the results of the iteration are undefined. The collection
* supports element removal, which removes the corresponding
* mapping from the map, via the {@code Iterator.remove},
* {@code Collection.remove}, {@code removeAll},
* {@code retainAll} and {@code clear} operations. It does not
* support the {@code add} or {@code addAll} operations.
*
* @return a collection view of the values contained in this map
*/
Collection values();
}