"How to learn Webservices - SOAP and REST?"

You can start with some basic example of REST API development using Jersey.

Sample tutorial :

Jersey hello world example

Read more example and information on below official website :

Jersey

You can also use other REST framework for development as well depending upon you need.

For SOAP API development you can use apache axis library, however now a days REST API are predominantly used across industry.

Thanks,

Bala