The issue I see here is that the yum repository for EC2 Amazon Linux AMI instance does not include any graphical binaries. These binaries include gtk and swt with gtk. You can either compile all dependencies or use another image. Since you are a newbie, I suggest you switch to an ubuntu image.
On an ubuntu image, you should be able to run apt-get to install missing dependencies:
For Java:
- sudo add-apt-repository ppa:webupd8team/java for oracle java
- sudo apt-get update
- sudo apt-get install oracle-java8-installer
For libswt:
- sudo apt-get install libswt-gtk-3-jni libswt-gtk-3-java
Another issue I can think of is that you are likely trying to run a graphical application. If that is the case, you will have to run it with a window manager like Xvnc or Xvfb.