How to extend functionality of expiry in ehCache 3.0

Question

I am using EhCache core 3.0. It internally uses BaseExpiry and Eh107Expiry class to check whether cache is expired or not. These classes implement Expiry interface. My query is, can we extend methods which are used to check whether cache is expired or not. I don't want to expire contents of the cache even if time is elapsed if my method is using some data from that cache.

Answer 1

Have a look at the dedicated section on Expiry in the documentation. It will help you understand what you can do and how to do it.

If that does not help you, please expand your question as suggested in comments.

Answer 2

If you add time-to-idle in xml or override getExpiryForAccess from Expiry interface,then your entries will not delete when you are accessing them.Below is the code to build Eh cache with custom Expire.This blog will help you for other properties with explanation.

        CacheConfigurationBuilder<Integer,String> cacheConfigurationBuilder = CacheConfigurationBuilder.newCacheConfigurationBuilder();
        cacheConfigurationBuilder.withExpiry(new Expiry() {
            @Override
            public Duration getExpiryForCreation(Object key, Object value) {
                return new Duration(120, TimeUnit.SECONDS);
            }

            @Override
            public Duration getExpiryForAccess(Object key, Object value) {
                return new Duration(120, TimeUnit.SECONDS);
            }

            @Override
            public Duration getExpiryForUpdate(Object key, Object oldValue, Object newValue) {
                return null;
            }
        })
                .usingEvictionPrioritizer(Eviction.Prioritizer.LFU)
                .withResourcePools(ResourcePoolsBuilder.newResourcePoolsBuilder().heap(200, EntryUnit.ENTRIES))
                        // adding defaultSerializer config service to configuration
                .add(new DefaultSerializerConfiguration(CompactJavaSerializer.class, SerializerConfiguration.Type.KEY))
                .buildConfig(Integer.class, String.class);

Answer 3

I guess you can use an ehcache decorator and reimplement isExpiry to add your own conditions. Please refer to https://www.ehcache.org/documentation/2.8/apis/cache-decorators.html.