MetadataCache

```
public interface MetadataCache
```
Represents a client cache of the immutable metadata (class descriptions and their associated property descriptions) for all metadata objects accessed during the life of a given server connection. Using a local metadata cache decreases the time needed to access an object's immutable metadata, therefore improving the performance of client applications. Note that any independent objects that are referenced by a class description, such as choice lists, are not cached.
Only a single, default metadata cache is available for a given server connection, which you can access by calling getDefaultInstance() on the Factory.MetadataCache class. This cache is also used internally. Metadata caching is enabled by default; to disable it, set the ConfigurationParameter.CLIENT_METADATA_CACHE instance to Boolean.FALSE.

See Also:

ConfigurationParameter

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`clear()` Removes all entries currently resident in the metadata cache.
`void`	`clear(Connection conn)` Removes all entries currently resident in the metadata cache.
`boolean`	`describedIsOfClass(ClassDescription cd, java.lang.String classIdent)` Returns whether a class description describes the class or subclass identified by a given class name or GUID string (`true`) or not (`false`).
`ClassDescription`	`getClassDescription(EngineObject eo)` Returns the class description for a given object.
`ClassDescription`	`getClassDescription(InstantiatingScope scope, java.lang.String classIdent)` Returns the class description for a given class and scope.
`ClassDescription[]`	`getClassDescriptions(InstantiatingScope scope, java.lang.String[] classIdents)` Returns zero or more class descriptions for a given scope and the classes specified by a class identities array, which can contain both class names and GUID strings.
`boolean`	`isEnabled()` Indicates whether the `MetadataCache` is enabled at any point in time.
`boolean`	`objectIsOfClass(EngineObject eo, java.lang.String classIdent)` Returns whether an object is instantiated from a class or subclass identified by a given class name or GUID string (`true`) or not (`false`).

- Method Detail
  - getClassDescription
```
ClassDescription getClassDescription(InstantiatingScope scope,
                                     java.lang.String classIdent)
```
    Returns the class description for a given class and scope. If the class description is not already resident, this method fetches it from the server and adds it to the metadata cache.
    
    Parameters:
    
    scope - An InstantiatingScope object specifying the scope of the class description.
    
    classIdent - A String specifying the name or GUID string of the class.
    
    Returns:
    
    A ClassDescription object.
  - getClassDescriptions
```
ClassDescription[] getClassDescriptions(InstantiatingScope scope,
                                        java.lang.String[] classIdents)
```
    Returns zero or more class descriptions for a given scope and the classes specified by a class identities array, which can contain both class names and GUID strings. Class descriptions not already resident are fetched from the server and added to the metadata cache. If a failure occurs while fetching a class description, the entire operation will fail. The returned array is the same size and in the same order as the class identities array; it is never null and its members are always valid class descriptions. Potentially, this operation is much more efficient than retrieving individual class descriptions because any non-resident class descriptions are fetched from the server in a single batch operation.
    
    Parameters:
    
    scope - An InstantiatingScope object specifying the scope of the class descriptions.
    
    classIdents - A String array specifying the class names or GUID strings of the class descriptions.
    
    Returns:
    
    An array of ClassDescription objects.
  - getClassDescription
```
ClassDescription getClassDescription(EngineObject eo)
```
    Returns the class description for a given object. If the class description is not already resident, this method fetches it from the server and adds it to the metadata cache.
    
    Parameters:
    
    eo - An EngineObject object.
    
    Returns:
    
    A ClassDescription object.
  - objectIsOfClass
```
boolean objectIsOfClass(EngineObject eo,
                        java.lang.String classIdent)
```
    Returns whether an object is instantiated from a class or subclass identified by a given class name or GUID string (true) or not (false). Class descriptions are fetched from the server and added to the metadata cache as needed.
    
    Parameters:
    
    eo - An EngineObject object.
    
    classIdent - A String specifying the name or GUID string of the class.
    
    Returns:
    
    true if the object specified by eo is instantiated from the class specified by classIdent; otherwise, returns false.
  - describedIsOfClass
```
boolean describedIsOfClass(ClassDescription cd,
                           java.lang.String classIdent)
```
    Returns whether a class description describes the class or subclass identified by a given class name or GUID string (true) or not (false). Class descriptions are fetched from the server and added to the metadata cache as needed.
    
    Parameters:
    
    cd - A ClassDescription object.
    
    classIdent - A String specifying the name or GUID string of the class.
    
    Returns:
    
    true if the class description specified by cd describes the class or subclass identified by classIdent; otherwise, returns false.
  - clear
```
void clear()
```
    Removes all entries currently resident in the metadata cache.
  - clear
```
void clear(Connection conn)
```
    Removes all entries currently resident in the metadata cache. If you are using the API cross-release classloading feature, your should use this signature.
    
    Parameters:
    
    conn - A Connection object.
  - isEnabled
```
boolean isEnabled()
```
    Indicates whether the MetadataCache is enabled at any point in time. The MetadataCache is enabled by default for Content Engine clients and disabled by default for the Content Engine server.
    
    Returns:
    
    true if the MetadataCache is enabled; otherwise, returns false.

getClassDescription

getClassDescriptions

getClassDescription

objectIsOfClass

describedIsOfClass

clear

clear

isEnabled