This is continued tutorial on Memcached which is distributed memory object caching server. Here are previous two tutorials before you go over this one.
- How to Install and Configure Memcached
- Memcached Java Client Tutorial using net.spy.spymemcached Library
In this tutorial we will go over Memcached Java Client using below two approaches:
com.whalin.Memcached-Java-Client Library
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<dependency> <groupId>com.whalin</groupId> <artifactId>Memcached-Java-Client</artifactId> <version>3.0.2</version> </dependency> |
com.googlecode.xmemcached Library
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<dependency> <groupId>com.googlecode.xmemcached</groupId> <artifactId>xmemcached</artifactId> <version>2.4.5</version> </dependency> |
Just add these two maven dependencies to your project’s pom.xml file to get library in your Eclipse workspace.
Here is a complete CrunchifyComWhalinXMemcachedClient.java program with all details.
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package crunchify.java.tutorials; import java.io.IOException; import java.util.concurrent.TimeoutException; import com.whalin.MemCached.MemCachedClient; import com.whalin.MemCached.SockIOPool; import net.rubyeye.xmemcached.XMemcachedClient; import net.rubyeye.xmemcached.exception.MemcachedException; /** * @author Crunchify.com * Version: 1.2.4 * Details: Use dependency com.whalin.Memcached-Java-Client and com.googlecode.xmemcached to retrieve, store Key Value pair * from MemCached Server */ public class CrunchifyComWhalinXMemcachedClient { public static void main(String[] args) { log("===================================== Approach-1: Using SpyMemcahed: https://crunchify.com/memcached-java-client-net-spy-spymemcached/ ===================================== \n"); log("===================================== Approach-2: Using com.whalin.Memcached-Java-Client =====================================\n"); implementWhalinMemcachedJavaClient(); log("===================================== Approach-3: Using com.googlecode.xmemcached Method =====================================\n"); implementXMemCachedClient(); log("===================================== Program Completed ===================================== \n"); } // Approach-1: Using SpyMemcahed: https://crunchify.com/memcached-java-client-net-spy-spymemcached/ // Approach-2: Using com.whalin.Memcached-Java-Client private static void implementWhalinMemcachedJavaClient() { String[] servers = { "localhost:11211" }; // This class is a connection pool for maintaning a pool of persistent connections to memcached servers. // The pool must be initialized prior to use. This should typically be early on in the lifecycle of the JVM instance. SockIOPool crunchfiyPool = SockIOPool.getInstance("Crunchify"); // Sets the minimum number of spare connections to maintain in our available pool. crunchfiyPool.setMinConn(2); // Sets the maximum number of spare connections allowed in our available pool. crunchfiyPool.setMaxConn(20); // Sets the list of all cache servers. crunchfiyPool.setServers(servers); // Sets the failover flag for the pool. If this flag is set to true, and a socket fails to connect, the pool will attempt to return a socket from // another server if one exists. // If set to false, then getting a socket will return null if it fails to connect to the requested server. crunchfiyPool.setFailover(true); // Sets the initial number of connections per server in the available pool. crunchfiyPool.setInitConn(30); // Set the sleep time between runs of the pool maintenance thread. If set to 0, then the maint thread will not be started. crunchfiyPool.setMaintSleep(90); // Sets the socket timeout for reads. crunchfiyPool.setSocketTO(2000); // Sets the aliveCheck flag for the pool. When true, this will attempt to talk to the server on every connection checkout to make sure the connection is // still valid. crunchfiyPool.setAliveCheck(true); crunchfiyPool.initialize(); // Creates a new instance of MemCachedClient accepting a passed in pool name. MemCachedClient crunchifyWhalinClient = new MemCachedClient("Crunchify"); // Adds data to the server; only the key and the value are specified. crunchifyWhalinClient.add("Java", "Crunchify.com"); crunchifyWhalinClient.add("WordPress", "WordPress.com"); crunchifyWhalinClient.add("Social", "Facebook.com"); log("==> Total 3 Records added to MemCached using com.whalin.Memcached-Java-Client Method\n"); // Retrieve a key from the server, using a specific hash. // If the data was compressed or serialized when compressed, it will automatically be decompressed or serialized, as appropriate.. log("Key: Java, Value: " + crunchifyWhalinClient.get("Java")); log("Key: WordPress, Value: " + crunchifyWhalinClient.get("WordPress")); log("Key: Social, Value: " + crunchifyWhalinClient.get("Social")); log("==> Total 3 Records Retrieved from MemCached using com.whalin.Memcached-Java-Client Method\n"); // Deletes an object from cache given cache key. crunchifyWhalinClient.delete("Social"); log("==> Record deleted using com.whalin.Memcached-Java-Client Method\n"); log("Key: Social, Value: " + crunchifyWhalinClient.get("Social")); log("==> Failure to get record Social as we deleted that before\n"); } // Approach-3: Using com.googlecode.xmemcached private static void implementXMemCachedClient() { String city = "New York"; String city2 = "San Francisco"; try { // XMemcached constructor,default weight is 1 XMemcachedClient xMemCachedclient = new XMemcachedClient("localhost", 11211); // Set a value xMemCachedclient.set("Crunchify", 3600, city); xMemCachedclient.set("Twitter", 3600, city2); // Get a value for specify key Object myCity = xMemCachedclient.get("Twitter"); log("=====> Key: Twitter, Value: " + xMemCachedclient.get("Twitter") + "\n"); // Get a value for specify key (set timeout of three seconds) myCity = xMemCachedclient.get("Crunchify", 3000); log("=====> Key: Crunchify, Value: " + xMemCachedclient.get("Crunchify", 3000) + "\n"); // Set a new expiration time for an existing item,using default opTimeout second. xMemCachedclient.touch("key", 30); xMemCachedclient.delete("Crunchify"); log("=====> Key: Crunchify, Value: " + xMemCachedclient.get("Crunchify") + "\n"); // delete value xMemCachedclient.delete("key"); // let's catch all exceptions } catch (IOException e) { e.printStackTrace(); } catch (MemcachedException e) { e.printStackTrace(); } catch (TimeoutException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); } } // Simple log utility private static void log(Object object) { System.out.println(object); } } |
Make sure you have Memcached server up and running.
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bash-3.2$ memcached -d -p 11211 |
Just run above command in Eclipse to see below result.
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===================================== Approach-1: Using SpyMemcahed: https://crunchify.com/memcached-java-client-net-spy-spymemcached/ ===================================== ===================================== Approach-2: Using com.whalin.Memcached-Java-Client ===================================== SLF4J: The requested version 1.7.16 by your slf4j binding is not compatible with [1.6] SLF4J: See http://www.slf4j.org/codes.html#version_mismatch for further details. ==> Total 3 Records added to MemCached using com.whalin.Memcached-Java-Client Method Key: Java, Value: Crunchify.com Key: WordPress, Value: WordPress.com Key: Social, Value: Facebook.com ==> Total 3 Records Retrieved from MemCached using com.whalin.Memcached-Java-Client Method 18:27:35.433 [main] DEBUG com.whalin.MemCached.MemCachedClient - ++++ deletion of key: Social from cache was a success ==> Record deleted using com.whalin.Memcached-Java-Client Method Key: Social, Value: null ==> Failure to get record Social as we deleted that before ===================================== Approach-3: Using com.googlecode.xmemcached Method ===================================== 18:27:35.456 [main] INFO net.rubyeye.xmemcached.XMemcachedClient - XMemcachedClient is using Text protocol 18:27:35.491 [main] INFO com.google.code.yanf4j.nio.impl.SelectorManager - Creating 8 reactors... 18:27:35.496 [main] INFO com.google.code.yanf4j.core.impl.AbstractController - The Controller started at localhost/127.0.0.1:0 ... 18:27:35.509 [Xmemcached-Reactor-0] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - session started 18:27:35.510 [Xmemcached-Reactor-0] INFO com.google.code.yanf4j.core.impl.AbstractController - Add a session: 127.0.0.1:11211 18:27:35.513 [main] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - After encodingset Crunchify 0 3600 8 New York 18:27:35.514 [Xmemcached-Reactor-2] DEBUG net.rubyeye.xmemcached.impl.Optimizer - Optimieze merge buffer:set Crunchify 0 3600 8 New York 18:27:35.514 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - send buffers: [ buffer:position=0,limit=34,capacity=34 ] 18:27:35.515 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - read 8 bytes from channel 18:27:35.515 [main] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - After encodingset Twitter 0 3600 13 San Francisco 18:27:35.515 [Xmemcached-Reactor-2] DEBUG net.rubyeye.xmemcached.impl.Optimizer - Optimieze merge buffer:set Twitter 0 3600 13 San Francisco 18:27:35.515 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - send buffers: [ buffer:position=0,limit=38,capacity=38 ] 18:27:35.515 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - read 8 bytes from channel 18:27:35.516 [main] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - After encodingget Twitter 18:27:35.517 [Xmemcached-Reactor-2] DEBUG net.rubyeye.xmemcached.impl.Optimizer - Optimieze merge buffer:get Twitter 18:27:35.517 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - send buffers: [ buffer:position=0,limit=13,capacity=13 ] 18:27:35.518 [main] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - After encodingget Twitter 18:27:35.518 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - read 40 bytes from channel 18:27:35.518 [Xmemcached-Reactor-2] DEBUG net.rubyeye.xmemcached.impl.Optimizer - Optimieze merge buffer:get Twitter 18:27:35.518 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - send buffers: [ buffer:position=0,limit=13,capacity=13 ] =====> Key: Twitter, Value: San Francisco 18:27:35.518 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - read 40 bytes from channel 18:27:35.519 [main] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - After encodingget Crunchify 18:27:35.519 [Xmemcached-Reactor-2] DEBUG net.rubyeye.xmemcached.impl.Optimizer - Optimieze merge buffer:get Crunchify 18:27:35.519 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - send buffers: [ buffer:position=0,limit=15,capacity=15 ] 18:27:35.519 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - read 36 bytes from channel 18:27:35.519 [main] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - After encodingget Crunchify 18:27:35.519 [Xmemcached-Reactor-2] DEBUG net.rubyeye.xmemcached.impl.Optimizer - Optimieze merge buffer:get Crunchify 18:27:35.519 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - send buffers: [ buffer:position=0,limit=15,capacity=15 ] =====> Key: Crunchify, Value: New York 18:27:35.520 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - read 36 bytes from channel 18:27:35.520 [main] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - After encodingtouch key 30 18:27:35.520 [Xmemcached-Reactor-2] DEBUG net.rubyeye.xmemcached.impl.Optimizer - Optimieze merge buffer:touch key 30 18:27:35.520 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - send buffers: [ buffer:position=0,limit=14,capacity=14 ] 18:27:35.520 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - read 11 bytes from channel 18:27:35.520 [main] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - After encodingdelete Crunchify 18:27:35.520 [Xmemcached-Reactor-2] DEBUG net.rubyeye.xmemcached.impl.Optimizer - Optimieze merge buffer:delete Crunchify 18:27:35.521 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - send buffers: [ buffer:position=0,limit=18,capacity=18 ] 18:27:35.521 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - read 9 bytes from channel 18:27:35.521 [main] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - After encodingget Crunchify 18:27:35.521 [Xmemcached-Reactor-2] DEBUG net.rubyeye.xmemcached.impl.Optimizer - Optimieze merge buffer:get Crunchify 18:27:35.521 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - send buffers: [ buffer:position=0,limit=15,capacity=15 ] =====> Key: Crunchify, Value: null 18:27:35.521 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - read 5 bytes from channel 18:27:35.521 [main] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - After encodingdelete key 18:27:35.521 [Xmemcached-Reactor-2] DEBUG net.rubyeye.xmemcached.impl.Optimizer - Optimieze merge buffer:delete key 18:27:35.521 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - send buffers: [ buffer:position=0,limit=12,capacity=12 ] ===================================== Program Completed ===================================== 18:27:35.522 [Xmemcached-Reactor-2] DEBUG com.google.code.yanf4j.core.impl.AbstractSession - read 11 bytes from channel |
As you see in above result, it’s easy to retrieve and save value and it’s a fastest way to have central caching solution for your production Java application.