Showing the basics of CAS

App.java

package com.couchbase.sample.showingcas;

import com.couchbase.client.CouchbaseClient;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.List;
import net.spy.memcached.CASResponse;
import net.spy.memcached.CASValue;
import net.spy.memcached.ops.OperationQueueFactory;


public class App 
{
    public static void main( String[] args ) throws URISyntaxException, IOException
    {

        List<URI> baselist = new ArrayList<URI>();

        baselist.add(new URI("http://127.0.0.1:8091/pools"));

        OperationQueueFactory afactory;

        CouchbaseClient cb = new CouchbaseClient(baselist, "default", "");
        cb.set("hello", 0, "world");
        System.err.println(cb.get("hello"));
        cb.get("hello");

        CASValue<Object> s = cb.gets("hello");
        // my programming logic would then see if I want to modify the object
        // by doing something with s.getValue().  deciding I do...
        System.err.println("***> Show updating a document with cas");
        CASResponse rv = cb.cas("hello", s.getCas(), "{\"hi\":\"there\"}");
        if (rv != CASResponse.OK) {
            // it can either be EXISTS or NOT_FOUND.  Do something logical.
            System.err.println("Failed document update owing to " + rv);
        } else {
            System.err.println("Updated document successfully.");
        }

        System.err.println("***> Show a fake failure, with a bad CAS");
        CASResponse frv = cb.cas("hello", 888, "{\"hi\":\"there\"}");
        if (frv != CASResponse.OK) {
            System.err.println("Failed document update owing to " + frv);
        } else {
            System.err.println("Updated document successfully.");
        }


        cb.shutdown();
        
    }
}