CacheStatisticsMXBean (JSR107 API and SPI 0.7 API)

```
@MXBean
public interface CacheStatisticsMXBean
```
Cache statistics.
Statistics are accumulated from the time a cache is created. They can be reset to zero using clear().
There are no defined consistency semantics for statistics. Refer to the implementation for precise semantics.
Each cache's statistics object must be registered with an ObjectName that is unique and has the following type and attributes:
Type: javax.cache:type=CacheStatistics
Required Attributes:
- CacheManager the name of the CacheManager
- Cache the name of the Cache
Since:

1.0

Author:

Greg Luck

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`clear()` Clears the statistics counters to 0 for the associated Cache.
`float`	`getAverageGetTime()` The mean time to execute gets.
`float`	`getAveragePutTime()` The mean time to execute puts.
`float`	`getAverageRemoveTime()` The mean time to execute removes.
`long`	`getCacheEvictions()` The total number of evictions from the cache.
`long`	`getCacheGets()` The total number of requests to the cache.
`float`	`getCacheHitPercentage()` This is a measure of cache efficiency.
`long`	`getCacheHits()` The number of get requests that were satisfied by the cache.
`long`	`getCacheMisses()` A miss is a get request which is not satisfied.
`float`	`getCacheMissPercentage()` Returns the percentage of cache accesses that did not find a requested entry in the cache.
`long`	`getCachePuts()` The total number of puts to the cache.
`long`	`getCacheRemovals()` The total number of removals from the cache.
`Date`	`getStartAccumulationDate()` The date from which statistics have been accumulated.

- Method Detail
  - clear
```
void clear()
```
    Clears the statistics counters to 0 for the associated Cache.
  - getStartAccumulationDate
```
Date getStartAccumulationDate()
```
    The date from which statistics have been accumulated. Because statistics can be cleared, this is not necessarily since the cache was started.
    
    Returns:
    the date statistics started being accumulated
  - getCacheHits
```
long getCacheHits()
```
    The number of get requests that were satisfied by the cache.
    In a caches with multiple tiered storage, a hit may be implemented as a hit to the cache or to the first tier.
    
    Returns:
    the number of hits
  - getCacheHitPercentage
```
float getCacheHitPercentage()
```
    This is a measure of cache efficiency. It is calculated as getCacheHits() divided by getCacheGets() * 100.
    
    Returns:
    the percentage of successful hits, as a decimal e.g 75.
  - getCacheMisses
```
long getCacheMisses()
```
    A miss is a get request which is not satisfied.
    In a simple cache a miss occurs when the cache does not satisfy the request.
    In a caches with multiple tiered storage, a miss may be implemented as a miss to the cache or to the first tier.
    In a read-through cache a miss is an absence of the key in the cache which will trigger a call to a CacheLoader. So it is still a miss even though the cache will load and return the value.
    Refer to the implementation for precise semantics.
    
    Returns:
    the number of misses
  - getCacheMissPercentage
```
float getCacheMissPercentage()
```
    Returns the percentage of cache accesses that did not find a requested entry in the cache. This is calculated as getCacheMisses() divided by getCacheGets() * 100.
    
    Returns:
    the percentage of accesses that failed to find anything
  - getCacheGets
```
long getCacheGets()
```
    The total number of requests to the cache. This will be equal to the sum of the hits and misses.
    A "get" is an operation that returns the current or previous value. It does not include checking for the existence of a key.
    In a caches with multiple tiered storage, a gets may be implemented as a get to the cache or to the first tier.
    
    Returns:
    the number of gets
  - getCachePuts
```
long getCachePuts()
```
    The total number of puts to the cache.
    A put is counted even if it is immediately evicted. Replaces, where a put occurs which overrides an existing mapping is counted as a put.
    
    Returns:
    the number of hits
  - getCacheRemovals
```
long getCacheRemovals()
```
    The total number of removals from the cache. This does not include evictions, where the cache itself initiates the removal to make space.
    
    Returns:
    the number of hits
  - getCacheEvictions
```
long getCacheEvictions()
```
    The total number of evictions from the cache. An eviction is a removal initiated by the cache itself to free up space. An eviction is not treated as a removal and does not appear in the removal counts.
    
    Returns:
    the number of evictions from the cache
  - getAverageGetTime
```
float getAverageGetTime()
```
    The mean time to execute gets.
    In a read-through cache the time taken to load an entry on miss is not included in get time.
    
    Returns:
    the time in µs
  - getAveragePutTime
```
float getAveragePutTime()
```
    The mean time to execute puts.
    
    Returns:
    the time in µs
  - getAverageRemoveTime
```
float getAverageRemoveTime()
```
    The mean time to execute removes.
    
    Returns:
    the time in µs

Interface CacheStatisticsMXBean

Method Summary

Method Detail

clear

getStartAccumulationDate

getCacheHits

getCacheHitPercentage

getCacheMisses

getCacheMissPercentage

getCacheGets

getCachePuts

getCacheRemovals

getCacheEvictions

getAverageGetTime

getAveragePutTime

getAverageRemoveTime