org.springframework.cache.support

Class NoOpCache

  • java.lang.Object
    • org.springframework.cache.support.NoOpCache
  • All Implemented Interfaces:
    Cache


    public class NoOpCache
    extends java.lang.Object
    implements Cache
    A no operation Cache implementation suitable for disabling caching.

    Will simply accept any items into the cache not actually storing them.

    Since:
    4.3.4
    Author:
    Costin Leau, Stephane Nicoll
    • Constructor Summary

      Constructors 
      Constructor and Description
      NoOpCache(java.lang.String name)
      Create a NoOpCache instance with the specified name.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method and Description
      void clear()
      Remove all mappings from the cache.
      void evict(java.lang.Object key)
      Evict the mapping for this key from this cache if it is present.
      Cache.ValueWrapper get(java.lang.Object key)
      Return the value to which this cache maps the specified key.
      <T> T get(java.lang.Object key, java.util.concurrent.Callable<T> valueLoader)
      Return the value to which this cache maps the specified key, obtaining that value from valueLoader if necessary.
      <T> T get(java.lang.Object key, java.lang.Class<T> type)
      Return the value to which this cache maps the specified key, generically specifying a type that return value will be cast to.
      java.lang.String getName()
      Return the cache name.
      java.lang.Object getNativeCache()
      Return the underlying native cache provider.
      void put(java.lang.Object key, java.lang.Object value)
      Associate the specified value with the specified key in this cache.
      Cache.ValueWrapper putIfAbsent(java.lang.Object key, java.lang.Object value)
      Atomically associate the specified value with the specified key in this cache if it is not set already.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • NoOpCache

        public NoOpCache(java.lang.String name)
        Create a NoOpCache instance with the specified name.
        Parameters:
        name - the name of the cache
    • Method Detail

      • getName

        public java.lang.String getName()
        Description copied from interface: Cache
        Return the cache name.
        Specified by:
        getName in interface Cache
      • getNativeCache

        public java.lang.Object getNativeCache()
        Description copied from interface: Cache
        Return the underlying native cache provider.
        Specified by:
        getNativeCache in interface Cache
      • get

        @Nullable
        public Cache.ValueWrapper get(java.lang.Object key)
        Description copied from interface: Cache
        Return the value to which this cache maps the specified key.

        Returns null if the cache contains no mapping for this key; otherwise, the cached value (which may be null itself) will be returned in a Cache.ValueWrapper.

        Specified by:
        get in interface Cache
        Parameters:
        key - the key whose associated value is to be returned
        Returns:
        the value to which this cache maps the specified key, contained within a Cache.ValueWrapper which may also hold a cached null value. A straight null being returned means that the cache contains no mapping for this key.
        See Also:
        Cache.get(Object, Class)
      • get

        @Nullable
        public <T> T get(java.lang.Object key,
                                   @Nullable
                                   java.lang.Class<T> type)
        Description copied from interface: Cache
        Return the value to which this cache maps the specified key, generically specifying a type that return value will be cast to.

        Note: This variant of get does not allow for differentiating between a cached null value and no cache entry found at all. Use the standard Cache.get(Object) variant for that purpose instead.

        Specified by:
        get in interface Cache
        Parameters:
        key - the key whose associated value is to be returned
        type - the required type of the returned value (may be null to bypass a type check; in case of a null value found in the cache, the specified type is irrelevant)
        Returns:
        the value to which this cache maps the specified key (which may be null itself), or also null if the cache contains no mapping for this key
        See Also:
        Cache.get(Object)
      • get

        @Nullable
        public <T> T get(java.lang.Object key,
                                   java.util.concurrent.Callable<T> valueLoader)
        Description copied from interface: Cache
        Return the value to which this cache maps the specified key, obtaining that value from valueLoader if necessary. This method provides a simple substitute for the conventional "if cached, return; otherwise create, cache and return" pattern.

        If possible, implementations should ensure that the loading operation is synchronized so that the specified valueLoader is only called once in case of concurrent access on the same key.

        If the valueLoader throws an exception, it is wrapped in a Cache.ValueRetrievalException

        Specified by:
        get in interface Cache
        Parameters:
        key - the key whose associated value is to be returned
        Returns:
        the value to which this cache maps the specified key
      • put

        public void put(java.lang.Object key,
                        @Nullable
                        java.lang.Object value)
        Description copied from interface: Cache
        Associate the specified value with the specified key in this cache.

        If the cache previously contained a mapping for this key, the old value is replaced by the specified value.

        Specified by:
        put in interface Cache
        Parameters:
        key - the key with which the specified value is to be associated
        value - the value to be associated with the specified key
      • putIfAbsent

        @Nullable
        public Cache.ValueWrapper putIfAbsent(java.lang.Object key,
                                                        @Nullable
                                                        java.lang.Object value)
        Description copied from interface: Cache
        Atomically associate the specified value with the specified key in this cache if it is not set already.

        This is equivalent to:

        
         Object existingValue = cache.get(key);
         if (existingValue == null) {
             cache.put(key, value);
             return null;
         } else {
             return existingValue;
         }
         
        except that the action is performed atomically. While all out-of-the-box CacheManager implementations are able to perform the put atomically, the operation may also be implemented in two steps, e.g. with a check for presence and a subsequent put, in a non-atomic way. Check the documentation of the native cache implementation that you are using for more details.
        Specified by:
        putIfAbsent in interface Cache
        Parameters:
        key - the key with which the specified value is to be associated
        value - the value to be associated with the specified key
        Returns:
        the value to which this cache maps the specified key (which may be null itself), or also null if the cache did not contain any mapping for that key prior to this call. Returning null is therefore an indicator that the given value has been associated with the key.
      • evict

        public void evict(java.lang.Object key)
        Description copied from interface: Cache
        Evict the mapping for this key from this cache if it is present.
        Specified by:
        evict in interface Cache
        Parameters:
        key - the key whose mapping is to be removed from the cache
      • clear

        public void clear()
        Description copied from interface: Cache
        Remove all mappings from the cache.
        Specified by:
        clear in interface Cache