java.lang.Object
- org.eclipse.persistence.queries.QueryResultsCachePolicy

All Implemented Interfaces:

Serializable, Cloneable
```
public class QueryResultsCachePolicy
extends Object
implements Serializable, Cloneable
```
PUBLIC: A QueryResultsCache policy dictates how a query's results will be cached. It allows an invalidation policy and a maximum number of results to be set. Query results are cached based on the parameter values of a query, and the maximum number of results refers to the maximum number of parameter sets results will be cached for.\ By default query result caching is not used.

See Also:

ReadQuery.setQueryResultsCachePolicy(QueryResultsCachePolicy), Serialized Form

Field Summary

Fields
Modifier and Type	Field	Description
`protected Class`	`cacheType`	Allows the identity map class type to be set.
`protected boolean`	`invalidateOnChange`	Allows the query cache to be invalidated when any object of any of the query classes is modified.
`protected Set<Class>`	`invalidationClasses`	Stores the set of classes that should trigger the query cached results to be invalidated.
`protected CacheInvalidationPolicy`	`invalidationPolicy`	Allows invalidation to be specified.
`protected boolean`	`isNullIgnored`	Allows the caching of null to be configured.
`protected int`	`maximumResultSets`	Specifies the cache size.

Constructor Summary

Constructors
Constructor	Description
`QueryResultsCachePolicy()`	PUBLIC: Build a QueryResultsCachePolicy with the default settings By default there is no invalidation of query results and the maximum number of results sets is 100.
`QueryResultsCachePolicy(int maximumResultSets)`	PUBLIC: Build a QueryResultsCachePolicy and supply a maximum for the number of results sets.
`QueryResultsCachePolicy(CacheInvalidationPolicy policy)`	PUBLIC: Build a QueryResultsCachePolicy and supply a CacheInvalidationPolicy.
`QueryResultsCachePolicy(CacheInvalidationPolicy policy, int maximumResultSets)`	PUBLIC: Build a QueryResultsCachePolicy and supply a CacheInvalidationPolicy and a maximum number of results sets.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`QueryResultsCachePolicy`	`clone()`
`CacheInvalidationPolicy`	`getCacheInvalidationPolicy()`	PUBLIC: Return the query cache invalidation policy.
`Class`	`getCacheType()`	PUBLIC: Return the type of the cache used for the query results.
`boolean`	`getInvalidateOnChange()`	PUBLIC: Return if any change to any object of the query class should cause the query results to be invalidated.
`Set<Class>`	`getInvalidationClasses()`	ADVANCED: Return the set of classes that should trigger the query cached results to be invalidated.
`int`	`getMaximumCachedResults()`	PUBLIC: Return the maximum cached results.
`boolean`	`isNullIgnored()`	PUBLIC: Return if null results should be cached or ignored.
`void`	`setCacheInvalidationPolicy(CacheInvalidationPolicy invalidationPolicy)`	PUBLIC: Set the query cache invalidation policy.
`void`	`setCacheType(Class cacheType)`	PUBLIC: Set the type of the cache used for the query results.
`void`	`setInvalidateOnChange(boolean invalidateOnChange)`	PUBLIC: Configure if any change to any object of the query class should cause the query results to be invalidated.
`void`	`setInvalidationClasses(Set<Class> invalidationClasses)`	ADVANCED: Set the set of classes that should trigger the query cached results to be invalidated.
`void`	`setIsNullIgnored(boolean isNullIgnored)`	PUBLIC: Set if null results should be cached or ignored.
`void`	`setMaximumCachedResults(int maximumResultSets)`	PUBLIC: Set the maximum cached results.
`void`	`useFullCache()`	PUBLIC: Set the type of the cache used for the query results to a FullIdentityMap.
`void`	`useLRUCache()`	PUBLIC: Set the type of the cache used for the query results to a CacheIdentityMap.
`void`	`useSoftCache()`	PUBLIC: Set the type of the cache used for the query results to a SoftIdentityMap.
`void`	`useSoftLRUCache()`	PUBLIC: Set the type of the cache used for the query results to a SoftCacheWeakIdentityMap.

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - invalidationPolicy
```
protected CacheInvalidationPolicy invalidationPolicy
```
    Allows invalidation to be specified.
  - maximumResultSets
```
protected int maximumResultSets
```
    Specifies the cache size.
  - cacheType
```
protected Class cacheType
```
    Allows the identity map class type to be set.
  - isNullIgnored
```
protected boolean isNullIgnored
```
    Allows the caching of null to be configured.
  - invalidateOnChange
```
protected boolean invalidateOnChange
```
    Allows the query cache to be invalidated when any object of any of the query classes is modified.
  - invalidationClasses
```
protected Set<Class> invalidationClasses
```
    Stores the set of classes that should trigger the query cached results to be invalidated.
- Constructor Detail
  - QueryResultsCachePolicy
```
public QueryResultsCachePolicy()
```
    PUBLIC: Build a QueryResultsCachePolicy with the default settings By default there is no invalidation of query results and the maximum number of results sets is 100.
  - QueryResultsCachePolicy
```
public QueryResultsCachePolicy(CacheInvalidationPolicy policy,
                               int maximumResultSets)
```
    PUBLIC: Build a QueryResultsCachePolicy and supply a CacheInvalidationPolicy and a maximum number of results sets.
    
    See Also:
    
    CacheInvalidationPolicy
  - QueryResultsCachePolicy
```
public QueryResultsCachePolicy(CacheInvalidationPolicy policy)
```
    PUBLIC: Build a QueryResultsCachePolicy and supply a CacheInvalidationPolicy. The default value of 100 will be used for the maximum number of result sets
    
    See Also:
    
    CacheInvalidationPolicy
  - QueryResultsCachePolicy
```
public QueryResultsCachePolicy(int maximumResultSets)
```
    PUBLIC: Build a QueryResultsCachePolicy and supply a maximum for the number of results sets. Results will be set not to expire in the cache.
- Method Detail
  - clone
```
public QueryResultsCachePolicy clone()
```
    Overrides:
    
    clone in class Object
  - getInvalidationClasses
```
public Set<Class> getInvalidationClasses()
```
    ADVANCED: Return the set of classes that should trigger the query cached results to be invalidated.
  - setInvalidationClasses
```
public void setInvalidationClasses(Set<Class> invalidationClasses)
```
    ADVANCED: Set the set of classes that should trigger the query cached results to be invalidated. This is normally computed by the query, but can be set in the case of native queries.
  - isNullIgnored
```
public boolean isNullIgnored()
```
    PUBLIC: Return if null results should be cached or ignored. By default they are cached. They can be ignored to allow a query cache to be used as a secondary cache index, and allow new objects to be insert, and still found.
  - setIsNullIgnored
```
public void setIsNullIgnored(boolean isNullIgnored)
```
    PUBLIC: Set if null results should be cached or ignored. By default they are cached. They can be ignored to allow a query cache to be used as a secondary cache index, and allow new objects to be insert, and still found.
  - getInvalidateOnChange
```
public boolean getInvalidateOnChange()
```
    PUBLIC: Return if any change to any object of the query class should cause the query results to be invalidated.
  - setInvalidateOnChange
```
public void setInvalidateOnChange(boolean invalidateOnChange)
```
    PUBLIC: Configure if any change to any object of the query class should cause the query results to be invalidated.
  - getCacheType
```
public Class getCacheType()
```
    PUBLIC: Return the type of the cache used for the query results. This defaults to a LRU cache (CacheIdentityMap), but can be set to any IdentityMap class, such as Full or Soft.
  - setCacheType
```
public void setCacheType(Class cacheType)
```
    PUBLIC: Set the type of the cache used for the query results. This defaults to a LRU cache (CacheIdentityMap), but can be set to any IdentityMap class, such as Full or Soft.
  - useFullCache
```
public void useFullCache()
```
    PUBLIC: Set the type of the cache used for the query results to a FullIdentityMap. This will cache all query results, so caution should be used to avoid running out of memory.
  - useSoftCache
```
public void useSoftCache()
```
    PUBLIC: Set the type of the cache used for the query results to a SoftIdentityMap. This will cache all query results, unless the JVM believes memory is low.
  - useSoftLRUCache
```
public void useSoftLRUCache()
```
    PUBLIC: Set the type of the cache used for the query results to a SoftCacheWeakIdentityMap. This will uses a fixed size LRU cache using Soft references, so will allow garbage collection when memory is low.
  - useLRUCache
```
public void useLRUCache()
```
    PUBLIC: Set the type of the cache used for the query results to a CacheIdentityMap. This will uses a fixed size LRU cache. This is the default.
  - getCacheInvalidationPolicy
```
public CacheInvalidationPolicy getCacheInvalidationPolicy()
```
    PUBLIC: Return the query cache invalidation policy. The cache invalidation policy defines how the query results are invalidated.
  - setCacheInvalidationPolicy
```
public void setCacheInvalidationPolicy(CacheInvalidationPolicy invalidationPolicy)
```
    PUBLIC: Set the query cache invalidation policy. The cache invalidation policy defines how the query results are invalidated.
  - getMaximumCachedResults
```
public int getMaximumCachedResults()
```
    PUBLIC: Return the maximum cached results. This defines the number of query result sets that will be cached. The LRU query results will be discarded when the max size is reached.
  - setMaximumCachedResults
```
public void setMaximumCachedResults(int maximumResultSets)
```
    PUBLIC: Set the maximum cached results. This defines the number of query result sets that will be cached. The LRU query results will be discarded when the max size is reached.

Class QueryResultsCachePolicy

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

invalidationPolicy

maximumResultSets

cacheType

isNullIgnored

invalidateOnChange

invalidationClasses

Constructor Detail

QueryResultsCachePolicy

QueryResultsCachePolicy

QueryResultsCachePolicy

QueryResultsCachePolicy

Method Detail

clone

getInvalidationClasses

setInvalidationClasses

isNullIgnored

setIsNullIgnored

getInvalidateOnChange

setInvalidateOnChange

getCacheType

setCacheType

useFullCache

useSoftCache

useSoftLRUCache

useLRUCache

getCacheInvalidationPolicy

setCacheInvalidationPolicy

getMaximumCachedResults

setMaximumCachedResults