Added a jackson example

Author: botenbreuk

src/main/java/nl/rdb/java_examples/entities/PersonJackson.java

@@ -0,0 +1,6 @@
+package nl.rdb.java_examples.entities;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+
+@JsonInclude(JsonInclude.Include.ALWAYS)
+public class PersonJackson extends Person {}

src/main/java/nl/rdb/java_examples/jackson/JacksonExample.java

@@ -9,6 +9,7 @@
 import lombok.extern.slf4j.Slf4j;
 import nl.rdb.java_examples.entities.Address;
 import nl.rdb.java_examples.entities.Person;
+import nl.rdb.java_examples.entities.PersonJackson;
 import nl.rdb.java_examples.jackson.deserializers.LocalDateTimeDeserializer;
 import nl.rdb.java_examples.scanner.Example;
 
@@ -46,6 +47,15 @@ void largeObjectToJsonSting() throws Exception {
         log.info("Length {}", test.getBytes(UTF_8).length);
     }
 
+    @Example
+    void emptyObjectToJson() throws Exception {
+        String personJson = objectMapper.writeValueAsString(new Person());
+        log.info("JSON: {}", personJson);
+
+        String personJsonJackson = objectMapper.writeValueAsString(new PersonJackson());
+        log.info("JSON: {}", personJsonJackson);
+    }
+
     @Example
     void dateTimeModule() throws Exception {
         record Test(LocalDateTime date) {}