Fix Jackson cannot construct instance of Java.time.LocalDate

Question

I am trying to read a csv file using Jackson csv Mapper and map the entries to a Pojo which has a LocalDate field. While trying to parse the file I am getting the following error

Cannot construct instance of java.time.LocalDate (no Creators, like default construct, exist): no String-argument constructor/factory method to deserialize from String value ('2019-12-01')\n at [Source: (com.fasterxml.jackson.dataformat.csv.impl.UTF8Reader)

I have tried the methods given in other answers but still getting the same results, Only Annotation which works is

@JsonDeserialize(using = LocalDateDeserializer.class)

I have tried to create a bean of Object Mapper and register its module in App Configuration file I created but still no Effect. Kindly someone help me

Pojo

@Data
class TestImport{

@JsonProperty("start_date")
LocalDate startDate;
}

Object Mapper Configuration:

 @Bean
    @Primary
    public ObjectMapper objectMapper(){
        ObjectMapper objectMapper=new ObjectMapper();
        objectMapper.registerModule(new JavaTimeModule());
        return objectMapper;
    }

File Reading Code:

public  <T> List<T> read(Class<T> Entity, MultipartFile file) throws Exception{
            InputStream inputStream = new BufferedInputStream(file.getInputStream());
            CsvSchema schema = csvMapper.schemaFor(Entity).withHeader().withColumnReordering(true);
            ObjectReader reader = csvMapper.readerFor(Entity).with(schema);
            List<T> result= reader.<T>readValues(inputStream).readAll();
            inputStream.close();
            return result;
    }

Pom.xml

 <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <dependencies>
        <dependency>
            <groupId>com.fasterxml.jackson.module</groupId>
            <artifactId>jackson-module-parameter-names</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.datatype</groupId>
            <artifactId>jackson-datatype-jdk8</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.datatype</groupId>
            <artifactId>jackson-datatype-jsr310</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-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-csv</artifactId>
            <version>2.10.1</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/io.github.millij/poi-object-mapper -->
        <dependency>
            <groupId>io.github.millij</groupId>
            <artifactId>poi-object-mapper</artifactId>
            <version>1.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>

        </dependency>
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>2.8.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.2</version>
        </dependency>
    </dependencies>

Can you read it as string and convert it from calendar or date to local date? — manuel, Jan 02 '20 at 11:13
How do you read this `CSV` file? For `CSV` you need to use [CsvMapper](https://github.com/FasterXML/jackson-dataformats-text/tree/master/csv) — Michał Ziober, Jan 02 '20 at 11:18
Are you sure the `ObjectMapper` you create is the one getting used? — Mark Rotteveel, Jan 02 '20 at 11:31
can you please post your full pom.xml so we know what Spring version that is used and that there is no other code interfering, and please post the code you are using to read the csv — Toerktumlare, Jan 02 '20 at 11:57
I am not sure if the Object mapper is being used but since I gave it @Primary annotation this should work? — Inderjit Chopra, Jan 02 '20 at 12:00
first `spring-web` is not needed since the spring web starter will pull in this. — Toerktumlare, Jan 02 '20 at 15:00
and i'd like to know why you are pulling in apache HttpClient seperatly and redis.client. The redis client should come with the redis starter, and if using Spring RestTemplate/WebClient it will use the underlying servers client (in your case HttpClient from tomcat) — Toerktumlare, Jan 02 '20 at 15:20

Michael Gantman · Answer 1 · 2020-01-02T14:56:01.350

1

In your pojo you need to set annotation
@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd") For more details look at the answer for question Spring Data JPA - ZonedDateTime format for json serialization

edited Jan 02 '20 at 14:56

answered Jan 02 '20 at 11:17

Michael Gantman

7,315
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if i have 20 Pojos with date field, do I need to write this at every POJO class? – Inderjit Chopra Jan 02 '20 at 11:57
Yes, you do, just like any other annotation. But you annotate a property, not the entire class. It is a property level annotation. First, try it on one and see if it works – Michael Gantman Jan 02 '20 at 12:04
But what if I want the serializer and deserializer work on its own without worrying about these extra annotations? I used the annotations listed in question and it worked but i want to design a more cohert and universal solution – Inderjit Chopra Jan 02 '20 at 12:10
I believe you will need to write a custom deserializer, but I haven't done so. So, I don't know the details. The annotations are an acceptable solution though – Michael Gantman Jan 02 '20 at 13:02

score 0 · Answer 2 · answered Jan 02 '20 at 15:12

0

jackson-datatype-jsr310 is registered by default if on the classpath as stated on Springs own blog Jackson-Modules Spring Blog so no need to register it manually in a new ObjectMapper at all.

answered Jan 02 '20 at 15:12

Toerktumlare

12,548
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Fix Jackson cannot construct instance of Java.time.LocalDate

2 Answers2