Don't work convert type boolean from Json with Srping Boot 2.x

Question

I use Spring Boot 2.x and maven

• pom.xml

     <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </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-rest</artifactId>
        </dependency>

         <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web-services</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-validation</artifactId>
        </dependency>

• json, That is sending.

{
  "name": "fan",

  "isCar": true,

  "year": 2020,

  "character": "W",

  "cost": 10,

  "status": "OPEN"
}

• a part of DTO

public abstract class DifferentTypesDtoFour extends DifferentTypesDtoTwo {

    private Integer year;

    private boolean isCar;

    public DifferentTypesDtoFour() {
    }

    public Integer getYear() {
        return year;
    }

    public void setYear(Integer year) {
        this.year = year;
    }

    public boolean isCar() {
        return isCar;
    }

    public void setCar(boolean car) {
        isCar = car;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        if (!super.equals(o)) return false;
        DifferentTypesDtoFour that = (DifferentTypesDtoFour) o;
        return isCar == that.isCar &&
                Objects.equals(year, that.year);
    }

    @Override
    public int hashCode() {
        return Objects.hash(super.hashCode(), year, isCar);
    }

    @Override
    public String toString() {
        return super.toString() + "\n" + "DifferentTypesDtoFour{" +
                "year=" + year +
                ", isCar=" + isCar +
                '}';
    }
}

I can 't understand the origin of this problem.

When the request comes to the rest controller , the dto receives the converted data.

Almost data is converted the correct, but the field isCar = false...

Why ?

Does anyone have any ideas how to fix this?

Update

I used the following:

public abstract class DifferentTypesDtoFour extends DifferentTypesDtoTwo {

    private Integer year;

    private boolean isCar;

    public DifferentTypesDtoFour() {
    }

    public Integer getYear() {
        return year;
    }

    public void setYear(Integer year) {
        this.year = year;
    }

    @JsonProperty(value = "isCar")
    public boolean isCar() {
        return isCar;
    }

    @JsonProperty(value = "isCar")
    public void setCar(boolean car) {
        isCar = car;
    }
...

}

The type boolean saved indeed, but when the data is back to rest-controller, the client receives a response and the type boolean again don't transform correct.

Answer 1

The problem is with your setter of isCar field - the setter method's name should be setIsCar instead of setCar so that the request json's isCar value can be mapped into your model's isCar property,

public void setIsCar(boolean isCar) {
    this.isCar = isCar;
}

Edit 1... As @Gimby mentioned that your getter name should be isIsCar, it will not affect while getting HTTP request but it will eventually look unmatched getter for that field - and you may consider re-naming your variable to avoid such typo issues.

Edit 2... One of the ways to get rid of the issue is using @JsonProperty without renaming methods as mentioned by @GabLeg,

@JsonProperty(value="isCar")
public void setCar(boolean car) {
    this.isCar = car;
}