[BAEL-9596] What's New in Jackson 3

jackson-modules/jackson-core-3/pom.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>jackson-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>jackson-core-3</artifactId>
+
+    <properties>
+        <jackson3.version>3.2.1</jackson3.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>tools.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson3.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>tools.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-xml</artifactId>
+            <version>${jackson3.version}</version>
+        </dependency>
+    </dependencies>
+
+</project>

jackson-modules/jackson-core-3/src/main/java/com/baeldung/jackson/whatsnew/MapperFactory.java

@@ -0,0 +1,24 @@
+package com.baeldung.jackson.whatsnew;
+
+import tools.jackson.core.json.JsonWriteFeature;
+import tools.jackson.databind.SerializationFeature;
+import tools.jackson.databind.cfg.DateTimeFeature;
+import tools.jackson.databind.json.JsonMapper;
+
+public class MapperFactory {
+
+    public static JsonMapper getMapper() {
+        return JsonMapper.builder()
+            .enable(SerializationFeature.INDENT_OUTPUT)
+            .disable(JsonWriteFeature.ESCAPE_NON_ASCII)
+            .configure(DateTimeFeature.WRITE_DATES_AS_TIMESTAMPS, false)
+            .build();
+    }
+
+    public static JsonMapper rebuildPretty(JsonMapper jsonMapper) {
+        return jsonMapper.rebuild()
+            .enable(SerializationFeature.INDENT_OUTPUT)
+            .build();
+    }
+
+}

jackson-modules/jackson-core-3/src/test/java/com/baeldung/jackson/whatsnew/DefaultBehaviorTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.jackson.whatsnew;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.LocalDateTime;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class DefaultBehaviorTest {
+
+    @Test
+    void givenJsonWithAdditionalField_whenReadValue_thenSuccessWithoutUnknownField() {
+        var json = "{\"name\":\"Alice\", \"unknownField\":\"ignored_value\"}";
+        var mapper = MapperFactory.getMapper();
+
+        var user = mapper.readValue(json, User.class);
+
+        assertThat(user)
+            .returns("Alice", User::name);
+    }
+
+    private record User(String name) {}
+}

jackson-modules/jackson-core-3/src/test/java/com/baeldung/jackson/whatsnew/Java8FeaturesTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.jackson.whatsnew;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.LocalDateTime;
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class Java8FeaturesTest {
+
+    @Test
+    void givenJava8TypesAndNoConfiguration_whenWriteValueAsString_thenSuccess() {
+        var now = LocalDateTime.now();
+        var event = new Event("Tech Talk", Optional.of("Jackson 3 overview"), now);
+        var mapper = MapperFactory.getMapper();
+
+        var json = mapper.writeValueAsString(event);
+        assertThat(json)
+            .isEqualTo("""
+                {
+                  "title" : "Tech Talk",
+                  "description" : "Jackson 3 overview",
+                  "eventDate" : "<now>"
+                }""".replace("<now>", now.toString()));
+        var deserialized = mapper.readValue(json, Event.class);
+        assertThat(deserialized)
+            .isEqualTo(event);
+    }
+
+    private record Event(String title, Optional<String> description, LocalDateTime eventDate) {}
+}

jackson-modules/jackson-core-3/src/test/java/com/baeldung/jackson/whatsnew/JsonNodeTest.java

@@ -0,0 +1,24 @@
+package com.baeldung.jackson.whatsnew;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.OptionalInt;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class JsonNodeTest {
+
+    @Test
+    void givenJson_whenReadTree_thenValueAccessorEnhanced() {
+        var json = "{\"product\":\"Laptop\",\"price\":1200}";
+        var root = MapperFactory.getMapper().readTree(json);
+
+        var product = root.get("product").asString();
+        var price = root.get("price").intValueOpt();
+
+        assertThat(product)
+            .isEqualTo("Laptop");
+        assertThat(price)
+            .isEqualTo(OptionalInt.of(1200));
+    }
+}

jackson-modules/jackson-core-3/src/test/java/com/baeldung/jackson/whatsnew/MapperFactoryTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.jackson.whatsnew;
+
+import org.junit.jupiter.api.Test;
+import tools.jackson.databind.SerializationFeature;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatNoException;
+
+class MapperFactoryTest {
+
+    @Test
+    void whenGetMapper_thenSuccess() {
+        assertThatNoException().isThrownBy(MapperFactory::getMapper);
+    }
+
+    @Test
+    void givenMapper_whenRebuildPretty_thenSuccess() {
+        var mapper = MapperFactory.getMapper();
+
+        var prettyMapper = MapperFactory.rebuildPretty(mapper);
+
+        assertThat(prettyMapper)
+            .isNotNull()
+            .isNotSameAs(mapper)
+            .returns(true, m -> m.isEnabled(SerializationFeature.INDENT_OUTPUT));
+    }
+}

jackson-modules/jackson-core-3/src/test/java/com/baeldung/jackson/whatsnew/UncheckedExceptionTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.jackson.whatsnew;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class UncheckedExceptionTest {
+
+    @Test
+    void givenMapperAndUserRecord_whenReadValue_thenSuccessNoTryCatchNeeded() {
+        var jsonPayloads = List.of("{\"name\":\"Matt\"}", "{\"name\":\"Jack\"}");
+        var mapper = MapperFactory.getMapper();
+
+        var users = jsonPayloads.stream()
+            .map(json -> mapper.readValue(json, User.class))
+            .toList();
+
+        assertThat(users)
+            .hasSize(2)
+            .containsExactlyInAnyOrder(new User("Matt"), new User("Jack"));
+    }
+
+    private record User(String name) {}
+}

jackson-modules/pom.xml

@@ -26,6 +26,7 @@
         <module>jackson-exceptions</module>
         <module>jackson-jr</module>
         <module>jackson-polymorphic-deserialization</module>
+        <module>jackson-core-3</module>
     </modules>
 
     <dependencies>