added jackson annotations for interfaces on spring generator

Author: HugoMario

src/main/resources/handlebars/JavaSpring/interface.mustache

@@ -1,6 +1,21 @@
+{{#jackson}}
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+{{/jackson}}
 /**
 * {{#description}}{{.}}{{/description}}{{^description}}{{classname}}{{/description}}
 */
+{{#jackson}}
+@JsonTypeInfo(
+  use = JsonTypeInfo.Id.NAME,
+  include = JsonTypeInfo.As.PROPERTY,
+  property = "type")
+@JsonSubTypes({
+  {{#subTypes}}
+  @JsonSubTypes.Type(value = {{classname}}.class, name = "{{classname}}"){{^@last}},{{/@last}}
+  {{/subTypes}}
+})
+{{/jackson}}
 public interface {{{classname}}} {
 
 }