BAEL-5936 - OffsetDateTime serialization with Jackson (#13680)

* BAEL-5936 - OffsetDateTime serialization with Jackson

* BAEL-5936 - Extracting methods and adding tests

* BAEL-5936 - Renaming test file

* BAEL-5936 - Changing test method names

* BAEL-5936 - removes implements serializable

jackson-modules/jackson-custom-conversions/src/main/java/com/baeldung/offsetdatetime/Main.java

@@ -0,0 +1,50 @@
+package com.baeldung.offsetdatetime;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+
+import java.time.OffsetDateTime;
+
+public class Main {
+    public static void main(String[] args) throws JsonProcessingException {
+        System.out.println(serializeUser());
+        System.out.println(customSerialize());
+        System.out.println(customDeserialize());
+    }
+
+    static String serializeUser() throws JsonProcessingException {
+        ObjectMapper objectMapper = new ObjectMapper();
+        objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+        objectMapper.registerModule(new JavaTimeModule());
+
+        User user = new User();
+        user.setCreatedAt(OffsetDateTime.parse("2021-09-30T15:30:00+01:00"));
+
+        return objectMapper.writeValueAsString(user);
+    }
+
+    static String customSerialize() throws JsonProcessingException {
+        ObjectMapper objectMapper = new ObjectMapper();
+
+        objectMapper.registerModule(new SimpleModule().addSerializer(OffsetDateTime.class, new OffsetDateTimeSerializer()));
+
+        User user = new User();
+        user.setCreatedAt(OffsetDateTime.parse("2021-09-30T15:30:00+01:00"));
+
+        return objectMapper.writeValueAsString(user);
+    }
+
+    static String customDeserialize() throws JsonProcessingException {
+        ObjectMapper objectMapper = new ObjectMapper();
+
+        objectMapper.registerModule(new SimpleModule().addDeserializer(OffsetDateTime.class, new OffsetDateTimeDeserializer()));
+
+        String jsonString = "{\"createdAt\":\"30-09-2021 15:30:00 +01:00\"}";
+        User returnedUser = objectMapper.readValue(jsonString, User.class);
+
+        return returnedUser.getCreatedAt().toString();
+    }
+}

jackson-modules/jackson-custom-conversions/src/main/java/com/baeldung/offsetdatetime/OffsetDateTimeDeserializer.java

@@ -0,0 +1,24 @@
+package com.baeldung.offsetdatetime;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+
+import java.io.IOException;
+import java.time.OffsetDateTime;
+import java.time.format.DateTimeFormatter;
+
+public class OffsetDateTimeDeserializer extends JsonDeserializer<OffsetDateTime> {
+    private static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter
+            .ofPattern("dd-MM-yyyy HH:mm:ss XXX");
+
+    @Override
+    public OffsetDateTime deserialize(JsonParser jsonParser, DeserializationContext deserializationContext)
+            throws IOException {
+        String dateAsString = jsonParser.getText();
+        if (dateAsString == null) {
+            throw new IOException("OffsetDateTime argument is null.");
+        }
+        return OffsetDateTime.parse(dateAsString, DATE_TIME_FORMATTER);
+    }
+}

jackson-modules/jackson-custom-conversions/src/main/java/com/baeldung/offsetdatetime/OffsetDateTimeSerializer.java

@@ -0,0 +1,23 @@
+package com.baeldung.offsetdatetime;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+
+import java.io.IOException;
+import java.time.OffsetDateTime;
+import java.time.format.DateTimeFormatter;
+
+public class OffsetDateTimeSerializer extends JsonSerializer<OffsetDateTime> {
+    private static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter
+            .ofPattern("dd-MM-yyyy HH:mm:ss XXX");
+
+    @Override
+    public void serialize(OffsetDateTime value, JsonGenerator jsonGenerator, SerializerProvider serializerProvider)
+            throws IOException {
+        if (value == null) {
+            throw new IOException("OffsetDateTime argument is null.");
+        }
+        jsonGenerator.writeString(DATE_TIME_FORMATTER.format(value));
+    }
+}

jackson-modules/jackson-custom-conversions/src/main/java/com/baeldung/offsetdatetime/User.java

@@ -0,0 +1,18 @@
+package com.baeldung.offsetdatetime;
+
+import java.time.OffsetDateTime;
+
+public class User {
+    private OffsetDateTime createdAt;
+
+    public User() {
+    }
+
+    public OffsetDateTime getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setCreatedAt(OffsetDateTime createdAt) {
+        this.createdAt = createdAt;
+    }
+}

jackson-modules/jackson-custom-conversions/src/test/java/com/baeldung/offsetdatetime/MainUnitTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.offsetdatetime;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+class MainUnitTest {
+
+    @Test
+    void givenUser_whenSerialized_thenCreatedDateIsSerialized() throws JsonProcessingException {
+        Assertions.assertEquals("{\"createdAt\":\"2021-09-30T15:30:00+01:00\"}", Main.serializeUser());
+    }
+
+    @Test
+    void givenUser_whenCustomSerialized_thenCreatedDateIsSerialized() throws JsonProcessingException {
+        Assertions.assertEquals("{\"createdAt\":\"30-09-2021 15:30:00 +01:00\"}", Main.customSerialize());
+    }
+
+    @Test
+    void givenUser_whenCustomDeserialized_thenCreatedDateIsDeserialized() throws JsonProcessingException {
+        Assertions.assertEquals("2021-09-30T15:30+01:00", Main.customDeserialize());
+    }
+}

jackson-modules/pom.xml

@@ -24,11 +24,6 @@
     </modules>
 
     <dependencies>
-        <dependency>
-            <groupId>com.fasterxml.jackson.core</groupId>
-            <artifactId>jackson-databind</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>
         <!--jackson for xml -->
         <dependency>
             <groupId>com.fasterxml.jackson.dataformat</groupId>