How to run simple bitcoin program?

Question

I've simply downloaded an API .jar file of a Coinbase. I've created a project dynamic web project. I added that API successfully into a reference library.

Here is my simple program:

import com.coinbase.api.Coinbase;
import com.coinbase.api.CoinbaseBuilder;

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

        try {

            Coinbase cb=new CoinbaseBuilder()
            .withApiKey(System.getenv("My API KEY"), System.getenv("MY API SECRET"))
            .build();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

When I run this program, it says:

Exception in thread "main" java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/type/TypeReference
    at com.coinbase.api.CoinbaseBuilder.build(CoinbaseBuilder.java:16)
    at Main.main(Main.java:11)
Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.core.type.TypeReference
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 2 more

Do I need to put something here? I have checked thrice: my API key is correct.