In this tutorial, we will explore how to iterate over an Infinispan cache. We’ll cover the necessary steps to set up a cache manager, create a replicated synchronous cache, store data, and iterate over the cache entries.
Prerequisites
Before getting started, ensure that you have the following prerequisites:
- JDK (Java Development Kit) installed on your machine.
- Infinispan library added to your project dependencies.
Iterating over an Infinispan Replicated Cache
The following example shows how to add some random keys/values in a replicated cache and then Iterate over the Cache:
import org.infinispan.Cache;
import org.infinispan.commons.api.CacheContainerAdmin;
import org.infinispan.configuration.cache.CacheMode;
import org.infinispan.configuration.cache.Configuration;
import org.infinispan.configuration.cache.ConfigurationBuilder;
import org.infinispan.configuration.global.GlobalConfigurationBuilder;
import org.infinispan.context.Flag;
import org.infinispan.manager.DefaultCacheManager;
import java.util.UUID;
public class InfinispanReplicated {
public static void main(String[] args) throws Exception {
GlobalConfigurationBuilder global = GlobalConfigurationBuilder.defaultClusteredBuilder();
DefaultCacheManager cacheManager = new DefaultCacheManager(global.build());
// Create a replicated synchronous configuration
ConfigurationBuilder builder = new ConfigurationBuilder();
builder.clustering().cacheMode(CacheMode.REPL_SYNC);
Configuration cacheConfig = builder.build();
// Create a cache
Cache<String, String> cache = cacheManager.administration()
.withFlags(CacheContainerAdmin.AdminFlag.VOLATILE)
.getOrCreateCache("cache", cacheConfig);
// Store the current node address in some random keys
for(int i=0; i < 10; i++) {
cache.put(UUID.randomUUID().toString(), cacheManager.getNodeAddress());
}
// Display the current cache contents for the whole cluster
cache.entrySet().forEach(entry -> System.out.printf("%s = %s\n", entry.getKey(), entry.getValue()));
// Display the current cache contents for this node
cache.getAdvancedCache().withFlags(Flag.SKIP_REMOTE_LOOKUP)
.entrySet().forEach(entry -> System.out.printf("%s = %s\n", entry.getKey(), entry.getValue()));
// Stop the cache manager and release all resources
cacheManager.stop();
}
}
As you can see, we are doing two types of iterations:
- An iteration over the whole cluster with a plain cache.entrySet().forEach Loop
- An iteration over the Local Infinispan Node with a cache.getAdvancedCache().withFlags(Flag.SKIP_REMOTE_LOOKUP) .entrySet().forEach
Iterating over a Distributed Cache
The iteration over a Distributed Cache is slightly different from the Replicated one:
public class InfinispanDistributed {
public static void main(String[] args) throws Exception {
// Setup up a clustered cache manager
GlobalConfigurationBuilder global = GlobalConfigurationBuilder.defaultClusteredBuilder();
// Initialize the cache manager
DefaultCacheManager cacheManager = new DefaultCacheManager(global.build());
//Create cache configuration
ConfigurationBuilder builder = new ConfigurationBuilder();
builder.clustering().cacheMode(CacheMode.DIST_SYNC);
// Obtain a cache
Cache<String, String> cache = cacheManager.administration().withFlags(CacheContainerAdmin.AdminFlag.VOLATILE)
.getOrCreateCache("cache", builder.build());
// Store the current node address in some random keys
for (int i = 0; i < 10; i++) {
cache.put(UUID.randomUUID().toString(), cacheManager.getNodeAddress());
}
// Display the current cache contents for the whole cluster
cache.entrySet().forEach(entry -> System.out.printf("%s = %s\n", entry.getKey(), entry.getValue()));
// Display the current cache contents for this node
// Note: By default numOwners=2, so in a cluster with 2 nodes, each node owns all the keys:
// some of the keys as "primary owner" and some keys as "backup owner"
cache.getAdvancedCache().withFlags(Flag.CACHE_MODE_LOCAL).entrySet()
.forEach(entry -> System.out.printf("%s = %s\n", entry.getKey(), entry.getValue()));
// Stop the cache manager and release all resources
cacheManager.stop();
}
}
As you can see, looping over the whole cluster is identical with the replicated example. On the other hand, you can iterate over the Local Node Cache with cache.getAdvancedCache().withFlags(Flag.CACHE_MODE_LOCAL).entrySet() .forEach
Conclusion
In this tutorial, we covered how to iterate over a replicated Infinispan cache. We learned how to set up a cache manager, create a replicated synchronous cache, store.
Source code:
