memcache distributed lock implementation code

import java.util.Map;
import java.util.Properties;
import java.util.concurrent.atomic.AtomicInteger;

import javax.annotation.Resource;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.danga.MemCached.MemCachedClient;
import com.danga.MemCached.SockIOPool;

@Controller
public class MemController {
	
   private AtomicInteger ai=new AtomicInteger(0);
    static {  
        String[] serverlist = { "127.0.0.1:11211"};  
        
        SockIOPool pool = SockIOPool.getInstance();  
        pool.setServers(serverlist);  
        pool.initialize();  
 }  
    
	private static final Logger logger = LoggerFactory.getLogger(MemController.class);
	
	@RequestMapping(value = "/testMem", method = RequestMethod.GET)
	public void testMem(HttpServletRequest req,Model model) {
	    MemCachedClient mc = new MemCachedClient();  
	    String key="test";
	    boolean b = mc.add(key, "1", 60000);
	    Integer object =null;
	    if(b){
	         object = (Integer) mc.get("test_atomic");
	        if(object==null){
	            mc.set("test_atomic", 1);
	        }else{
	            object=object+1;
	            mc.set("test_atomic", object);
	        }
	        
	        mc.delete(key);
	    }else{
	        ai.getAndIncrement();
	    }
	    
	    
	    System.out.println("--------------object:"+object+",error:"+ai.get());
	    
	    
	    
	}
	
	

}

 I tested it with ab and found no problem