Membase server to couchbase server migration : Java client

I was using aspymemcached client to connect to my membase server.
code look like :

public static MemcachedClient MemcachedClient(String bucketName){
    	URI server1 = new URI("http://192.168.100.111:8091/pools");
        URI server2 = new URI("http://127.0.0.1:8091/pools");
        ArrayList<URI> serverList = new ArrayList<URI>();
        serverList.add(server1);
        serverList.add(server2);
        return  new MemcachedClient(serverList, bucketName, "");
}

For putting object in cache :

public static void makeMembaseCacheEntry(final String key, final int expiryTime, final Object value, final String bucketName) {
	MemcachedClient client = getMembaseClient(bucketName);
	if (client != null) {
		client.set(key, expiryTime, value);       
}

For getting object from cache :

   public static Object getMembaseCacheEntry(String key) {
		Object value = null;
         try {
            MemcachedClient client = getMembaseClient(bucketName);
            if (client != null) {
                value = client.get(key);
            }
        } catch (Exception e) {
        }
		return value;
}

Now I planning to upgrade membase server to couchbase server, hence I have to use couchbase client java API (Ref : http://docs.couchbase.com/developer/java-2.1/java-intro.html).
In cousebase client all operation performed on JsonObject ref :

http://docs.couchbase.com/developer/java-2.0/documents-basics.html

So how can I migrate above two methods to couchbase client

There is a section in the old 3.x documentation on this, as the Java SDK 2.0 aligned to the 3.0 server release. Have a look at that.