In contract-first approach Java classes are generated from xsd schema file. The file in this project is located in src/main/resources as countries.xsd
In order to generate java classes you need to run mvn clean compile.
The jaxb2-maven-plugin plugin will generate Java classes. If you use idea remember to mark
the generated source directory (target/generated-sources/jaxb)
Sample request files can be found in sample_requests directory. You should send post request
with the target url: http://localhost:8080/ws. Remember to set Content-Type header value
as text/xml.