ContextCache (Spring Framework 5.3.7 API)

All Known Implementing Classes:

DefaultContextCache
```
public interface ContextCache
```
ContextCache defines the SPI for caching Spring ApplicationContexts within the Spring TestContext Framework.
A ContextCache maintains a cache of ApplicationContexts keyed by MergedContextConfiguration instances, potentially configured with a maximum size and a custom eviction policy.
Rationale

Context caching can have significant performance benefits if context initialization is complex. Although the initialization of a Spring context itself is typically very quick, some beans in a context — for example, an embedded database or a LocalContainerEntityManagerFactoryBean for working with JPA — may take several seconds to initialize. Hence it often makes sense to perform that initialization only once per test suite or JVM process.

Since:

4.2

Author:

Sam Brannen, Juergen Hoeller

See Also:

ContextCacheUtils.retrieveMaxCacheSize()

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`CONTEXT_CACHE_LOGGING_CATEGORY` The name of the logging category used for reporting `ContextCache` statistics.
`static int`	`DEFAULT_MAX_CONTEXT_CACHE_SIZE` The default maximum size of the context cache: 32.
`static String`	`MAX_CONTEXT_CACHE_SIZE_PROPERTY_NAME` System property used to configure the maximum size of the `ContextCache` as a positive integer.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`clear()` Clear all contexts from the cache, clearing context hierarchy information as well.
`void`	`clearStatistics()` Clear hit and miss count statistics for the cache (i.e., reset counters to zero).
`boolean`	`contains(MergedContextConfiguration key)` Determine whether there is a cached context for the given key.
`ApplicationContext`	`get(MergedContextConfiguration key)` Obtain a cached `ApplicationContext` for the given key.
`int`	`getHitCount()` Get the overall hit count for this cache.
`int`	`getMissCount()` Get the overall miss count for this cache.
`int`	`getParentContextCount()` Determine the number of parent contexts currently tracked within the cache.
`void`	`logStatistics()` Log the statistics for this `ContextCache` at `DEBUG` level using the "org.springframework.test.context.cache" logging category.
`void`	`put(MergedContextConfiguration key, ApplicationContext context)` Explicitly add an `ApplicationContext` instance to the cache under the given key, potentially honoring a custom eviction policy.
`void`	`remove(MergedContextConfiguration key, DirtiesContext.HierarchyMode hierarchyMode)` Remove the context with the given key from the cache and explicitly close it if it is an instance of `ConfigurableApplicationContext`.
`void`	`reset()` Reset all state maintained by this cache including statistics.
`int`	`size()` Determine the number of contexts currently stored in the cache.

- Field Detail
  - CONTEXT_CACHE_LOGGING_CATEGORY
```
static final String CONTEXT_CACHE_LOGGING_CATEGORY
```
    The name of the logging category used for reporting ContextCache statistics.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_MAX_CONTEXT_CACHE_SIZE
```
static final int DEFAULT_MAX_CONTEXT_CACHE_SIZE
```
    The default maximum size of the context cache: 32.
    
    Since:
    
    4.3
    
    See Also:
    
    MAX_CONTEXT_CACHE_SIZE_PROPERTY_NAME, Constant Field Values
  - MAX_CONTEXT_CACHE_SIZE_PROPERTY_NAME
```
static final String MAX_CONTEXT_CACHE_SIZE_PROPERTY_NAME
```
    System property used to configure the maximum size of the ContextCache as a positive integer. May alternatively be configured via the SpringProperties mechanism.
    Note that implementations of ContextCache are not required to actually support a maximum cache size. Consult the documentation of the corresponding implementation for details.
    
    Since:
    
    4.3
    
    See Also:
    
    DEFAULT_MAX_CONTEXT_CACHE_SIZE, Constant Field Values
- Method Detail
  - contains
```
boolean contains(MergedContextConfiguration key)
```
    Determine whether there is a cached context for the given key.
    
    Parameters:
    
    key - the context key (never null)
    
    Returns:
    
    true if the cache contains a context with the given key
  - get
```
@Nullable
ApplicationContext get(MergedContextConfiguration key)
```
    Obtain a cached ApplicationContext for the given key.
    The hit and miss counts must be updated accordingly.
    
    Parameters:
    
    key - the context key (never null)
    
    Returns:
    
    the corresponding ApplicationContext instance, or null if not found in the cache
    
    See Also:
    
    remove(org.springframework.test.context.MergedContextConfiguration, org.springframework.test.annotation.DirtiesContext.HierarchyMode)
  - put
```
void put(MergedContextConfiguration key,
         ApplicationContext context)
```
    Explicitly add an ApplicationContext instance to the cache under the given key, potentially honoring a custom eviction policy.
    
    Parameters:
    
    key - the context key (never null)
    
    context - the ApplicationContext instance (never null)
  - remove
```
void remove(MergedContextConfiguration key,
            @Nullable
            DirtiesContext.HierarchyMode hierarchyMode)
```
    Remove the context with the given key from the cache and explicitly close it if it is an instance of ConfigurableApplicationContext.
    Generally speaking, this method should be called to properly evict a context from the cache (e.g., due to a custom eviction policy) or if the state of a singleton bean has been modified, potentially affecting future interaction with the context.
    In addition, the semantics of the supplied HierarchyMode must be honored. See the Javadoc for DirtiesContext.HierarchyMode for details.
    
    Parameters:
    
    key - the context key; never null
    
    hierarchyMode - the hierarchy mode; may be null if the context is not part of a hierarchy
  - size
```
int size()
```
    Determine the number of contexts currently stored in the cache.
    If the cache contains more than Integer.MAX_VALUE elements, this method must return Integer.MAX_VALUE.
  - getParentContextCount
```
int getParentContextCount()
```
    Determine the number of parent contexts currently tracked within the cache.
  - getHitCount
```
int getHitCount()
```
    Get the overall hit count for this cache.
    A hit is any access to the cache that returns a non-null context for the queried key.
  - getMissCount
```
int getMissCount()
```
    Get the overall miss count for this cache.
    A miss is any access to the cache that returns a null context for the queried key.
  - reset
```
void reset()
```
    Reset all state maintained by this cache including statistics.
    
    See Also:
    
    clear(), clearStatistics()
  - clear
```
void clear()
```
    Clear all contexts from the cache, clearing context hierarchy information as well.
  - clearStatistics
```
void clearStatistics()
```
    Clear hit and miss count statistics for the cache (i.e., reset counters to zero).
  - logStatistics
```
void logStatistics()
```
    Log the statistics for this ContextCache at DEBUG level using the "org.springframework.test.context.cache" logging category.
    The following information should be logged.
    - name of the concrete ContextCache implementation
    - size()
    - parent context count
    - hit count
    - miss count
    - any other information useful for monitoring the state of this cache

Interface ContextCache

Rationale

Field Summary

Method Summary

Field Detail

CONTEXT_CACHE_LOGGING_CATEGORY

DEFAULT_MAX_CONTEXT_CACHE_SIZE

MAX_CONTEXT_CACHE_SIZE_PROPERTY_NAME

Method Detail

contains

get

put

remove

size

getParentContextCount

getHitCount

getMissCount

reset

clear

clearStatistics

logStatistics