weiss.util
Interface Map<KeyType,ValueType>

All Superinterfaces:
java.io.Serializable
All Known Implementing Classes:
HashMap, TreeMap

public interface Map<KeyType,ValueType>
extends java.io.Serializable

Map interface. A map stores key/value pairs. In our implementations, duplicate keys are not allowed.


Nested Class Summary
static interface Map.Entry<KeyType,ValueType>
          The interface used to access the key/value pairs in a map.
 
Method Summary
 void clear()
          Removes all key value pairs from the map.
 boolean containsKey(KeyType key)
          Tests if this map contains a given key.
 Set<Map.Entry<KeyType,ValueType>> entrySet()
          Return a set of Map.Entry objects corresponding to the key/value pairs in the map.
 ValueType get(KeyType key)
          Returns the value in the map associated with the key.
 boolean isEmpty()
          Tests if this map is empty.
 Set<KeyType> keySet()
          Returns the keys in the map.
 ValueType put(KeyType key, ValueType value)
          Adds the key value pair to the map, overriding the original value if the key was already present.
 ValueType remove(KeyType key)
          Remove the key and its value from the map.
 int size()
          Returns the number of keys in this map.
 Collection<ValueType> values()
          Returns the values in the map.
 

Method Detail

size

int size()
Returns the number of keys in this map.

Returns:
the number of keys in this collection.

isEmpty

boolean isEmpty()
Tests if this map is empty.

Returns:
true if the size of this map is zero.

containsKey

boolean containsKey(KeyType key)
Tests if this map contains a given key.

Parameters:
key - the key to search for.
Returns:
true if the map contains the key.

get

ValueType get(KeyType key)
Returns the value in the map associated with the key.

Parameters:
key - the key to search for.
Returns:
the value that matches the key or null if the key is not found. Since null values are allowed, checking if the return value is null may not be a safe way to ascertain if the key is present in the map.

put

ValueType put(KeyType key,
              ValueType value)
Adds the key value pair to the map, overriding the original value if the key was already present.

Parameters:
key - the key to insert.
value - the value to insert.
Returns:
the old value associated with the key, or null if the key was not present prior to this call.

remove

ValueType remove(KeyType key)
Remove the key and its value from the map.

Parameters:
key - the key to remove.
Returns:
the previous value associated with the key, or null if the key was not present prior to this call.

clear

void clear()
Removes all key value pairs from the map.


keySet

Set<KeyType> keySet()
Returns the keys in the map.

Returns:
the keys in the map.

values

Collection<ValueType> values()
Returns the values in the map. There may be duplicates.

Returns:
the values in the map.

entrySet

Set<Map.Entry<KeyType,ValueType>> entrySet()
Return a set of Map.Entry objects corresponding to the key/value pairs in the map.

Returns:
the key/value pairs in the map.