Connecting to Memcached Service with Java

To connect to Memcached using a Java program, you need to add the Memcached JAR file to your classpath.

Download link for the JAR file from this site: spymemcached-2.10.3.jar.

Download link for the JAR file from Google Code: spymemcached-2.10.3.jar (requires a VPN).

The following program assumes that the Memcached service is hosted on 127.0.0.1 with port 11211.

Connection Example

Connecting to Memcached with Java

MemcachedJava.java File:

import net.spy.memcached.MemcachedClient;
import java.net.*;

public class MemcachedJava {
   public static void main(String[] args) {
      try {
         // Connect to Memcached service locally
         MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
         System.out.println("Connection to server successful.");

         // Close the connection
         mcc.shutdown();

      } catch (Exception ex) {
         System.out.println(ex.getMessage());
      }
   }
}

In this program, we use InetSocketAddress to connect to the Memcached service at IP 127.0.0.1 and port 11211.

Running the above code will output the following if the connection is successful:

Connection to server successful.

Set Operation Example

The following uses java.util.concurrent.Future to store data.

MemcachedJava.java File:

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
   public static void main(String[] args) {

      try {
         // Connect to the local Memcached service
         MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
         System.out.println("Connection to server successful.");

         // Store data
         Future fo = mcc.set("tutorialpro", 900, "Free Education");

         // Check storage status
         System.out.println("set status:" + fo.get());

         // Output the value
         System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

         // Close the connection
         mcc.shutdown();

      } catch (Exception ex) {
         System.out.println(ex.getMessage());
      }
   }
}

Running the program will output:

Connection to server successful.
set status:true
tutorialpro value in cache - Free Education

Add Operation Example

MemcachedJava.java File:

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
   public static void main(String[] args) {

      try {

         // Connect to the local Memcached service
         MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
         System.out.println("Connection to server successful.");

         // Add data
         Future fo = mcc.set("tutorialpro", 900, "Free Education");

         // Print status
         System.out.println("set status:" + fo.get());

         // Output
         System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

         // Add
         fo = mcc.add("tutorialpro", 900, "memcached");

         // Print status
         System.out.println("add status:" + fo.get());

         // Add new key
         fo = mcc.add("tutorialpro", 900, "All Free Compilers");

         // Print status
         System.out.println("add status:" + fo.get());

         // Output
         System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

         // Close the connection
         mcc.shutdown();

      } catch (Exception ex) {
         System.out.println(ex.getMessage());
      }
   }
}

Replace Operation Example

MemcachedJava.java File:

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
   public static void main(String[] args) {

      try {
         // Connect to the local Memcached service
         MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
         System.out.println("Connection to server successful.");

         // Add the first key-value pair
         Future fo = mcc.set("tutorialpro", 900, "Free Education");

         // Output the status after adding
         System.out.println("add status:" + fo.get());

         // Get the value corresponding to the key
         System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

         // Add a new key
         fo = mcc.replace("tutorialpro", 900, "Largest Tutorials' Library");

         // Output the status after setting
         System.out.println("replace status:" + fo.get());

         // Get the value corresponding to the key
         System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

         // Close the connection
         mcc.shutdown();

      } catch (Exception ex) {
         System.out.println(ex.getMessage());
      }
   }
}

Append Operation Example

MemcachedJava.java File:

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
   public static void main(String[] args) {

      try {

         // Connect to the local Memcached service
         MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
         System.out.println("Connection to server successful.");

         // Add data
         Future fo = mcc.set("tutorialpro", 900, "Free Education");

         // Output the status after setting
         System.out.println("set status:" + fo.get());

         // Get the value corresponding to the key

System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

// Perform data append operation on an existing key
fo = mcc.append("tutorialpro", 900, " for All");

// Output the status after the set method execution
System.out.println("append status:" + fo.get());

// Retrieve the value corresponding to the key
System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

// Close the connection
mcc.shutdown();

} catch(Exception ex) {
System.out.println(ex.getMessage());
}
}
}

Prepend Operation Example

MemcachedJava.java File:

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
public static void main(String[] args) {

try{

// Connect to the local Memcached service
MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
System.out.println("Connection to server successful.");

// Add data
Future fo = mcc.set("tutorialpro", 900, "Education for All");

// Output the status after the set method execution
System.out.println("set status:" + fo.get());

// Retrieve the value corresponding to the key
System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

// Perform data prepend operation on an existing key
fo = mcc.prepend("tutorialpro", 900, "Free ");

// Output the status after the set method execution
System.out.println("prepend status:" + fo.get());

// Retrieve the value corresponding to the key
System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

// Close the connection
mcc.shutdown();

} catch(Exception ex) {
System.out.println(ex.getMessage());
}
}
}

CAS Operation Example

MemcachedJava.java File:

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.CASValue;
import net.spy.memcached.CASResponse;
import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
public static void main(String[] args) {

try{

// Connect to the local Memcached service
MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
System.out.println("Connection to server successful.");

// Add data
Future fo = mcc.set("tutorialpro", 900, "Free Education");

// Output the status after the set method execution
System.out.println("set status:" + fo.get());

// Retrieve the value using the get method
System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

// Obtain the CAS token using the gets method
CASValue casValue = mcc.gets("tutorialpro");

// Output the CAS token value
System.out.println("CAS token - " + casValue);

// Attempt to update data using the cas method
CASResponse casresp = mcc.cas("tutorialpro", casValue.getCas(), 900, "Largest Tutorials-Library");

// Output the CAS response information
System.out.println("CAS Response - " + casresp);

// Output the value
System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

// Close the connection
mcc.shutdown();

} catch(Exception ex) {
System.out.println(ex.getMessage());
}
}
}

Get Operation Example

MemcachedJava.java File:

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
public static void main(String[] args) {

try{

// Connect to the local Memcached service
MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
System.out.println("Connection to server successful.");

// Add data
Future fo = mcc.set("tutorialpro", 900, "Free Education");

// Output the status after the set method execution
System.out.println("set status:" + fo.get());

// Retrieve the value using the get method
System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

// Close the connection
mcc.shutdown();

} catch(Exception ex) {
System.out.println(ex.getMessage());
}
}
}

Gets Operation Example, CAS

MemcachedJava.java File:

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.CASValue;
import net.spy.memcached.CASResponse;
import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
public static void main(String[] args) {

try{

// Connect to the local Memcached service
MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
System.out.println("Connection to server successful.");

// Add data
Future fo = mcc.set("tutorialpro", 900, "Free Education");

// Output the status after the set method execution
System.out.println("set status:" + fo.get());

// Retrieve the value from the cache for the key tutorialpro
System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

// Obtain the CAS token using the gets method
CASValue casValue = mcc.gets("tutorialpro");

// Output the CAS token value
System.out.println("CAS value in cache - " + casValue);

// Close the connection
mcc.shutdown();

} catch(Exception ex) {
System.out.println(ex.getMessage());
}
}
}

System.out.println(ex.getMessage());
      }
   }
}

Delete Operation Example

MemcachedJava.java File:

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
   public static void main(String[] args) {

      try{

         // Connect to the local Memcached service
         MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
         System.out.println("Connection to server successful.");

         // Add data
         Future fo = mcc.set("tutorialpro", 900, "World's largest online tutorials library");

         // Print the status after executing the set method
         System.out.println("set status:" + fo.get());

         // Retrieve the value corresponding to the key
         System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

         // Perform data deletion operation on an existing key
        fo = mcc.delete("tutorialpro");

         // Print the status after executing the delete method
         System.out.println("delete status:" + fo.get());

         // Retrieve the value corresponding to the key
         System.out.println("tutorialpro value in cache - " + mcc.get("tutorialpro"));

         // Close the connection
         mcc.shutdown();

      }catch(Exception ex) {
         System.out.println(ex.getMessage());
      }
   }
}

Incr/Decr Operation Example

MemcachedJava.java File:

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
   public static void main(String[] args) {

      try{

         // Connect to the local Memcached service
         MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
         System.out.println("Connection to server successful.");

         // Add numeric value
         Future fo = mcc.set("number", 900, "1000");

         // Print the status after executing the set method
         System.out.println("set status:" + fo.get());

         // Retrieve the value corresponding to the key
         System.out.println("value in cache - " + mcc.get("number"));

         // Increment and print
         System.out.println("value in cache after increment - " + mcc.incr("number", 111));

         // Decrement and print
         System.out.println("value in cache after decrement - " + mcc.decr("number", 112));

         // Close the connection
         mcc.shutdown();

      }catch(Exception ex) {
         System.out.println(ex.getMessage());
      }
   }
}