5

I use Java 10 with latest Spring spring-boot-starter-parent 2.1.0.RELEASE

POM configuration:

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.0.RELEASE</version>
    </parent>

    <dependencies>          
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-xml</artifactId>
            <version>2.9.7</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.7</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.module</groupId>
            <artifactId>jackson-module-jaxb-annotations</artifactId>
            <version>2.9.7</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.jaxrs</groupId>
            <artifactId>jackson-jaxrs-json-provider</artifactId>
            <version>2.9.7</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.6</version>
        </dependency>
        <dependency>
            <groupId>org.codehaus.woodstox</groupId>
            <artifactId>woodstox-core-asl</artifactId>
            <version>4.4.1</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.1</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-core</artifactId>
            <version>2.3.0.1</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-impl</artifactId>
            <version>2.3.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mapstruct</groupId>
            <artifactId>mapstruct-jdk8</artifactId>
            <version>1.2.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.jxls</groupId>
            <artifactId>jxls-poi</artifactId>
            <version>1.0.15</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>8.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security.oauth</groupId>
            <artifactId>spring-security-oauth2</artifactId>
            <version>2.3.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.security.oauth.boot</groupId>
            <artifactId>spring-security-oauth2-autoconfigure</artifactId>
            <version>2.1.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.session</groupId>
            <artifactId>spring-session-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-mail</artifactId>
        </dependency>
    </dependencies>

Rest Endpoint:

    @GetMapping("{id}")
    public ResponseEntity<?> get(@PathVariable String id) {
        return transactionRepository
                .findById(Integer.parseInt(id))
                .map(mapper::toDTO)
                .map(ResponseEntity::ok)
                .orElseGet(() -> notFound().build());
    }

DTO:

public class PaymentTransactionsDTO {

    private Integer id;

    private String status;

    private LocalDateTime created_at;

    private String merchant;
    .... getters and setters
}

But when I try to return JSON data for LocalDateTime created_at I get empty result. I suppose that LocalDateTime is not properly converted into JSON value.

Can you advice how I can fix this issue?

user1285928
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  • 29
  • 98
  • 147

5 Answers5

9

JSON serialization is driven by Jackson's ObjectMapper, which I recommend configuring explicitely. For proper serialization of the Java 8 date and time objects, make sure to

  • register the JavaTimeModule
  • disable writing dates as timestamps
  • setting the date format (use StdDateFormat)

Description of StdDateFormat:

Default DateFormat implementation used by standard Date serializers and deserializers. For serialization defaults to using an ISO-8601 compliant format (format String "yyyy-MM-dd'T'HH:mm:ss.SSSZ") and for deserialization, both ISO-8601 and RFC-1123.

Recommended configuration:

@Configuration
public class JacksonConfig {

    @Bean
    public ObjectMapper objectMapper() {
        return new ObjectMapper()
            .setAnnotationIntrospector(new JacksonAnnotationIntrospector())
            .registerModule(new JavaTimeModule())
            .setDateFormat(new StdDateFormat())
            .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    }

} }

Examples of serialized date and time objects:

  • LocalDate: 2018-11-21
  • LocalTime: 11:13:13.274
  • LocalDateTime: 2018-11-21T11:13:13.274
  • ZonedDateTime: 2018-11-21T11:13:13.274+01:00

Edit: standalone dependencies (already included transitively in spring-boot-starter-web):

  • com.fasterxml.jackson.core:jackson-annotations
  • com.fasterxml.jackson.core:jackson-databind
  • com.fasterxml.jackson.datatype:jackson-datatype-jsr310
Peter Walser
  • 15,208
  • 4
  • 51
  • 78
5

Try using @JsonFormat on your created_at field.

@JsonFormat(pattern="yyyy-MM-dd")
@DateTimeFormat(iso = DateTimeFormat.ISO.TIME)
private LocalDateTime created_at;
Pooja Aggarwal
  • 1,163
  • 6
  • 14
1

You need to add converter and register in spring eg. baeldung.com/spring-mvc-custom-data-binder

Vipul Pandey
  • 1,507
  • 11
  • 20
1

You can type your PaymentTransactionsDTO "created_at" attribute as a String and use a converter to convert the String to LocalDate (type of the attribute created_at of your entity "PaymentTransactions")

@Component
public class PaymentTransactionsConverter implements Converter<PaymentTransactionsDTO, PaymentTransactions> {

    @Override
    public PaymentTransactions convert(PaymentTransactionsDTO paymentTransactionsDTO) {

        PaymentTransactions paymentTransactions = new PaymentTransactions();
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");

        ...

        paymentTransactions.setCreated_at(LocalDate.parse(paymentTransactionsDTO.getCreated_at(), formatter));

        return paymentTransactions;
    }
}
veben
  • 19,637
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0

My dates defined as LocalDateTime were been serializaded as an array like this:

"timestamp": [
    2023,
    2,
    15,
    10,
    30,
    45,
    732425200
],

So following the Peter Walser answer and using some code of that topic, here is what I did in my WebConfig.java:

@Configuration
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {

  // other configs

  @Override
  public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
    WebMvcConfigurer.super.extendMessageConverters(converters);
    converters.add(new MappingJackson2HttpMessageConverter(
        new Jackson2ObjectMapperBuilder()
            .dateFormat(new StdDateFormat())
            .featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
            .build()));
  }

}

Now everything is good again:

"timestamp": "2023-02-15T10:32:06.5170689",

Try play around with some Jackson builder properties, hope it's been helpful.