public V put ( K key , V value ) { if ( key == null ) { throw new NullPointerException ( "null keys not allowed" ) ; } if ( value == null ) { throw new NullPointerException ( "null values not allowed" ) ; } purgeBeforeWrite ( ) ; return super . put ( key , value ) ; }
Puts a key - value mapping into this map . Neither the key nor the value may be null .