BAEL-2475: Add sample code and tests

jackson/src/main/java/com/baeldung/jackson/deserialization/immutable/MaritalAwarePerson.java

@@ -0,0 +1,58 @@
+package com.baeldung.jackson.deserialization.immutable;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonPOJOBuilder;
+
+@JsonDeserialize(builder = MaritalAwarePerson.Builder.class)
+public class MaritalAwarePerson {
+
+    private final String name;
+    private final int age;
+    private final Boolean married;
+
+    private MaritalAwarePerson(String name, int age, Boolean married) {
+        this.name = name;
+        this.age = age;
+        this.married = married;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public Boolean getMarried() {
+        return married;
+    }
+
+    @JsonPOJOBuilder
+    static class Builder {
+        String name;
+        int age;
+        Boolean married;
+
+        Builder withName(String name) {
+            this.name = name;
+            return this;
+        }
+
+        Builder withAge(int age) {
+            this.age = age;
+            return this;
+        }
+
+        Builder withMarried(boolean married) {
+            this.married = married;
+            return this;
+        }
+
+        public MaritalAwarePerson build() {
+            return new MaritalAwarePerson(name, age, married);
+        }
+
+
+    }
+}

jackson/src/main/java/com/baeldung/jackson/deserialization/immutable/Person.java

@@ -0,0 +1,24 @@
+package com.baeldung.jackson.deserialization.immutable;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class Person {
+
+    private final String name;
+    private final int age;
+
+    @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
+    public Person(@JsonProperty("name") String name, @JsonProperty("age") int age) {
+        this.name = name;
+        this.age = age;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getAge() {
+        return age;
+    }
+}

jackson/src/test/java/com/baeldung/jackson/deserialization/immutable/ImmutableObjectDeserializationUnitTest.java

@@ -0,0 +1,40 @@
+package com.baeldung.jackson.deserialization.immutable;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.junit.Assert.*;
+
+public class ImmutableObjectDeserializationUnitTest {
+
+    @Test
+    public void testPublicConstructor() throws IOException {
+        final String json = "{\"name\":\"Frank\",\"age\":50}";
+        Person person = new ObjectMapper().readValue(json, Person.class);
+
+        assertEquals("Frank", person.getName());
+        assertEquals(50, person.getAge());
+    }
+
+    @Test
+    public void testBuilderNullField() throws IOException {
+        final String json = "{\"name\":\"Frank\",\"age\":50}";
+        MaritalAwarePerson person = new ObjectMapper().readValue(json, MaritalAwarePerson.class);
+
+        assertEquals("Frank", person.getName());
+        assertEquals(50, person.getAge());
+        assertNull(person.getMarried());
+    }
+
+    @Test
+    public void testBuilderAllFields() throws IOException {
+        final String json = "{\"name\":\"Frank\",\"age\":50,\"married\":true}";
+        MaritalAwarePerson person = new ObjectMapper().readValue(json, MaritalAwarePerson.class);
+
+        assertEquals("Frank", person.getName());
+        assertEquals(50, person.getAge());
+        assertTrue(person.getMarried());
+    }
+}