Package net.targetr.wtm3.cache

Class ResourceCache

java.lang.Object

net.targetr.wtm3.cache.ResourceCache

Direct Known Subclasses:

ClassPathResourceCache, SpeedTestResourceCache, ZipFileResourceCache

public abstract class ResourceCache
extends Object

Caches resources on the classpath in memory.

Author:

Dr Michael Gardiner

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ResourceCache.CacheEntry	Represents a single entry in the resource cache.

Constructor Summary

Constructors

Constructor	Description
ResourceCache(int maxCacheEntries, long maxCacheSizeBytes)	Constructs a ResourceCache with specified maximum entries and size limits.

Method Summary

Modifier and Type	Method	Description
boolean	contains(String path)	Check if a resource is in the classpath.
ResourceCache.CacheEntry	get(String path)	Get a resource quickly by using cache if possible.
void	invalidate()	Invalidate the cache.
protected abstract InputStream	openInputStream(String path)	Opens an input stream to the resource.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ResourceCache

public ResourceCache(int maxCacheEntries,
 long maxCacheSizeBytes)

Constructs a ResourceCache with specified maximum entries and size limits.

Parameters:

maxCacheEntries - the maximum number of top-level entries allowed before eviction.

maxCacheSizeBytes - the maximum size in bytes of all entries combined before eviction.

Method Details

get

public ResourceCache.CacheEntry get(String path)
                             throws IOException

Get a resource quickly by using cache if possible.

Parameters:

path - the path to the resource in the class path.

Returns:

CacheEntry containing byte array of resource data.

Throws:

IOException - An exception occurred while reading the resource from class path.

openInputStream

protected abstract InputStream openInputStream(String path)
                                        throws IOException

Opens an input stream to the resource.

Parameters:

path - the path to the resource in the class path.

Returns:

an input stream to the resource, or null if not found.

Throws:

IOException - if an I/O error occurs.

contains

public boolean contains(String path)

Check if a resource is in the classpath.

Parameters:

path - the path to the resource in the class path.

Returns:

true if the resource is in the classpath, false otherwise.

invalidate

public void invalidate()

Invalidate the cache. All items in the cache will be removed.