BAEL-4687: added spring boot jackson configuration example

spring-boot-modules/pom.xml

@@ -68,6 +68,7 @@
         <module>spring-boot-vue</module>
         <module>spring-boot-xml</module>
         <module>spring-boot-actuator</module>
+        <module>spring-boot-jackson</module>
     </modules>
 
 

spring-boot-modules/spring-boot-jackson/pom.xml

@@ -0,0 +1,21 @@
+<?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">
+    <parent>
+        <artifactId>parent-boot-2</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-boot-2</relativePath>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>spring-boot-jackson</artifactId>
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+    </dependencies>
+
+</project>

spring-boot-modules/spring-boot-jackson/src/main/java/com/baeldung/boot/jackson/Application.java

@@ -0,0 +1,12 @@
+package com.baeldung.boot.jackson;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+}

spring-boot-modules/spring-boot-jackson/src/main/java/com/baeldung/boot/jackson/config/CoffeeConfiguration.java

@@ -0,0 +1,43 @@
+package com.baeldung.boot.jackson.config;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
+import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
+import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
+
+import java.time.format.DateTimeFormatter;
+
+@Configuration
+public class CoffeeConfiguration {
+    public static final String dateTimeFormat = "dd-MM-yyyy HH:mm";
+    private LocalDateTimeSerializer localDateTimeSerializer = new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(dateTimeFormat));
+
+    @Bean
+    public Jackson2ObjectMapperBuilderCustomizer jsonCustomizer() {
+        return builder -> builder.serializationInclusion(JsonInclude.Include.NON_NULL)
+                .serializers(localDateTimeSerializer);
+    }
+
+    @Bean
+    @Primary
+    public ObjectMapper objectMapper() {
+        JavaTimeModule module = new JavaTimeModule();
+        module.addSerializer(localDateTimeSerializer);
+        return new ObjectMapper()
+                .setSerializationInclusion(JsonInclude.Include.NON_NULL)
+                .registerModule(module);
+    }
+
+    @Bean
+    @Primary
+    public Jackson2ObjectMapperBuilder jackson2ObjectMapperBuilder() {
+        return new Jackson2ObjectMapperBuilder()
+                .serializers(localDateTimeSerializer)
+                .serializationInclusion(JsonInclude.Include.NON_NULL);
+    }
+}

spring-boot-modules/spring-boot-jackson/src/main/java/com/baeldung/boot/jackson/controller/CoffeeController.java

@@ -0,0 +1,25 @@
+package com.baeldung.boot.jackson.controller;
+
+import com.baeldung.boot.jackson.model.Coffee;
+import com.baeldung.boot.jackson.model.CoffeeResponse;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.time.LocalDateTime;
+
+@RestController
+public class CoffeeController {
+
+    @GetMapping("/coffee")
+    public CoffeeResponse<Coffee> createCoffee(@RequestParam(required = false) String brand,
+                                               @RequestParam(required = false) String name) {
+        Coffee coffee = new Coffee()
+                .setBrand(brand)
+                .setName(name);
+
+        return new CoffeeResponse<Coffee>()
+                .setDate(LocalDateTime.now())
+                .setBody(coffee);
+    }
+}

spring-boot-modules/spring-boot-jackson/src/main/java/com/baeldung/boot/jackson/model/Coffee.java

@@ -0,0 +1,26 @@
+package com.baeldung.boot.jackson.model;
+
+public class Coffee {
+
+    private String name;
+
+    private String brand;
+
+    public String getName() {
+        return name;
+    }
+
+    public Coffee setName(String name) {
+        this.name = name;
+        return this;
+    }
+
+    public String getBrand() {
+        return brand;
+    }
+
+    public Coffee setBrand(String brand) {
+        this.brand = brand;
+        return this;
+    }
+}

spring-boot-modules/spring-boot-jackson/src/main/java/com/baeldung/boot/jackson/model/CoffeeResponse.java

@@ -0,0 +1,28 @@
+package com.baeldung.boot.jackson.model;
+
+import java.time.LocalDateTime;
+
+public class CoffeeResponse<T> {
+
+    private LocalDateTime date;
+
+    private T body;
+
+    public LocalDateTime getDate() {
+        return date;
+    }
+
+    public CoffeeResponse<T> setDate(LocalDateTime date) {
+        this.date = date;
+        return this;
+    }
+
+    public T getBody() {
+        return body;
+    }
+
+    public CoffeeResponse<T> setBody(T body) {
+        this.body = body;
+        return this;
+    }
+}

spring-boot-modules/spring-boot-jackson/src/main/resources/application.properties

@@ -0,0 +1,3 @@
+spring.jackson.default-property-inclusion=non_null
+spring.jackson.serialization.write-dates-as-timestamps=false
+spring.jackson.date-format=dd-MM-yyyy HH:mm

spring-boot-modules/spring-boot-jackson/src/test/java/com/baeldung/boot/jackson/CoffeeIntegrationTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.boot.jackson;
+
+import com.baeldung.boot.jackson.config.CoffeeConfiguration;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@SpringBootTest(classes = Application.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+public class CoffeeIntegrationTest {
+
+    @Autowired
+    TestRestTemplate restTemplate;
+
+    @Test
+    public void whenQueryCoffeeWithoutParam_thenNullIsNotInserted() {
+        String formattedDate = DateTimeFormatter.ofPattern(CoffeeConfiguration.dateTimeFormat)
+                .format(LocalDateTime.now());
+        String brand = "Lavazza";
+
+        String url = "/coffee?brand=" + brand;
+        String response = restTemplate.getForObject(url, String.class);
+
+        assertThat(response).isEqualTo(
+                "{\"date\":\"" + formattedDate + "\",\"body\":{\"brand\":\"" + brand + "\"}}");
+    }
+}