java.lang.IllegalArgumentException: No converter found for return value of type
Solution 1:
The problem was that one of the nested objects in Foo didn't have any getter/setter
Solution 2:
Add the below dependency to your pom.xml:
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.10.0.pr3</version>
</dependency>