Add Adapter Sample

jsonb/src/main/java/com/baeldung/adapter/PersonAdapter.java

@@ -0,0 +1,26 @@
+package com.baeldung.adapter;
+
+import javax.json.Json;
+import javax.json.JsonObject;
+import javax.json.bind.adapter.JsonbAdapter;
+
+import com.baeldung.jsonb.Person;
+
+public class PersonAdapter implements JsonbAdapter<Person, JsonObject> {
+
+    @Override
+    public JsonObject adaptToJson(Person p) throws Exception {
+        return Json.createObjectBuilder()
+            .add("id", p.getId())
+            .add("name", p.getName())
+            .build();
+    }
+
+    @Override
+    public Person adaptFromJson(JsonObject adapted) throws Exception {
+        Person person = new Person();
+        person.setId(adapted.getInt("id"));
+        person.setName(adapted.getString("name"));
+        return person;
+    }
+}

jsonb/src/main/java/com/baeldung/jsonb/Person.java

@@ -22,10 +22,10 @@ public class Person {
     private BigDecimal salary;
 
     public Person() {
+        this(0, "", "", 0, LocalDate.now(), new BigDecimal(0));
     }
 
     public Person(int id, String name, String email, int age, LocalDate registeredDate, BigDecimal salary) {
-        super();
         this.id = id;
         this.name = name;
         this.email = email;

jsonb/src/test/java/com/baeldung/jsonb/JsonbTest.java

@@ -17,6 +17,8 @@ import javax.json.bind.config.PropertyOrderStrategy;
 import org.apache.commons.collections4.ListUtils;
 import org.junit.Test;
 
+import com.baeldung.adapter.PersonAdapter;
+
 public class JsonbTest {
 
     @Test
@@ -155,4 +157,32 @@ public class JsonbTest {
             .equals(person));
     }
 
+    @Test
+    public void givenPersonObject_whenSerializeWithAdapter_thenGetPersonJson() {
+        JsonbConfig config = new JsonbConfig().withAdapters(new PersonAdapter());
+        Jsonb jsonb = JsonbBuilder.create(config);
+        Person person = new Person(1, "Jhon", "jhon@test.com", 0, LocalDate.of(2019, 9, 7), BigDecimal.valueOf(1000.0));// new Person(1, "Jhon");
+        String jsonPerson = jsonb.toJson(person);
+        // @formatter:off
+        String jsonExpected = 
+            "{\"id\":1," +
+             "\"name\":\"Jhon\"}";
+        // @formatter:on
+        assertTrue(jsonExpected.equals(jsonPerson));
+    }
+
+    @Test
+    public void givenPersonJson_whenDeserializeWithAdapter_thenGetPersonObject() {
+        JsonbConfig config = new JsonbConfig().withAdapters(new PersonAdapter());
+        Jsonb jsonb = JsonbBuilder.create(config);
+        Person person = new Person(1, "Jhon", "jhon@test.com", 0, LocalDate.of(2019, 9, 7), BigDecimal.valueOf(1000.0));// new Person(1, "Jhon");
+        // @formatter:off
+        String jsonPerson = 
+            "{\"id\":1," + 
+             "\"name\":\"Jhon\"}";
+        // @formatter:on
+        assertTrue(jsonb.fromJson(jsonPerson, Person.class)
+            .equals(person));
+    }
+
 }