Hi,
Trying to use assisted inject and find it pretty neat, the minor
detail is that it does not quite work for me yet :-)
I have created a Map wrapper to ease switching of caches (typically to
something like Coherence) for my application. I want the Map to be
returned "in a Singleton scope, based on the value of the (assisted)
parameter". I am doing:
bind(CacheFactory.class).toProvider(
FactoryProvider.newFactory(CacheFactory.class,
NamedCacheLocal.class) );
And I have:
/**
* A factory for named caches, that later might hide its
implementation using a cluster wide storage.
*/
public interface CacheFactory {
//had to be named create to work with guice assisted inject, so
renamed from getNamedCache
public NamedCache create(String name);
}
public interface NamedCache<K,V> extends Map<K,V> {
public int getHitPercent();
public String getHitPercentString();
...
}
/**
* A named cache with a local map as implementation for storage.
*/
public class NamedCacheLocal<K,V> implements NamedCache<K,V> {
...
/**
* Constructs a NamedCacheLocal with its dependencies.
*/
@Inject
public NamedCacheLocal(@Assisted String cacheName) {
...
}
I have this (failing) unit test that checks that the same cache is
used for the same name:
System.out.println("doing put / get test");
NamedCache<String,String> namedCache =
namedCacheFactory.create("myCache");
namedCache.put("fisk","fesk");
for(int i=0;i<10; i++){
Object o = namedCache.get("non-hit");
namedCache.put("test"+i,"testval"+i);
}
Object hit = namedCache.get("fisk");
System.out.println("cache " + namedCache + " delivered value "
+ hit + " to a hit percent of " + namedCache.getHitPercentString());
assertTrue(namedCache.getHitPercent() > 8 &&
namedCache.getHitPercent() < 10);
NamedCache<String,String> namedCacheWithSameName =
namedCacheFactory.create("myCache");
for(int i=0;i<10; i++){
String val = namedCacheWithSameName.get("test"+i);
System.out.println("got val from cache: " + val);
}
//should have used the same reference, thus hit pct now higher
System.out.println("done with cache " +
namedCacheWithSameName);
assertTrue(namedCache.getHitPercent() > 10);
assertTrue(namedCache.equals(namedCacheWithSameName));
So is the thing I put in quotation marks in the intro ("in a Singleton
scope, based on the value of the (assisted) parameter") even possible
just by Guice config, or do I have to go two steps back and one
forward and just implement the CacheFactory myself with this logic?
The first thing I tried was
bind( CacheFactory.class ).
toProvider( FactoryProvider.newFactory(CacheFactory.class,
NamedCacheLocal.class) ) .
in ( Singleton.class );
But that (of course) just gives me a singleton CacheFactory, not the
NamedCacheLocal "singleton" based on the assisted factory parameter.
Cheers,
Sondre
--
You received this message because you are subscribed to the Google Groups
"google-guice" group.
To post to this group, send email to google-gu...@googlegroups.com.
To unsubscribe from this group, send email to
google-guice+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/google-guice?hl=en.
