Java Community | Help. Code. Learn.•2mo ago

Issue: API Returning Empty JSON Objects {}

facing an issue in my Spring Boot project. My API for fetching products is returning empty objects: [{}, {}, {}, {}] But I have verified that data exists in my H2 database.

47 Replies

JavaBot•2mo ago

⌛ This post has been reserved for your question.

Hey @Shruti! Please use /close or the Close Post button above when your problem is solved. Please remember to follow the help guidelines. This post will be automatically marked as dormant after 300 minutes of inactivity.

TIP: Narrow down your issue to simple and precise questions to maximize the chance that others will reply in here.

ayylmao123xdd•2mo ago

hi can you show the code the service one

JavaBot•2mo ago

💤 Post marked as dormant

This post has been inactive for over 300 minutes, thus, it has been archived. If your question was not answered yet, feel free to re-open this post or create a new one. In case your post is not getting any attention, you can try to use /help ping. Warning: abusing this will result in moderative actions taken against you.

YoChrisRapNow•2mo ago

package com.example.EcomTutDemo11.service; import com.example.EcomTutDemo11.model.Product; import com.example.EcomTutDemo11.repo.ProductRepo; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; @Service

public class ProdcutService {
    @Autowired
    private ProductRepo repo;

    public List<Product> getAllProducts(){

        return repo.findAll();
    }

}

public class ProdcutService {
    @Autowired
    private ProductRepo repo;

    public List<Product> getAllProducts(){

        return repo.findAll();
    }

}

This message has been formatted automatically. You can disable this using /preferences.

Peter Rader•2mo ago

Have you considered using data-rest ( https://spring.io/projects/spring-data-rest )?

Spring Data REST

Level up your Java code and explore what Spring can do for you.

ayylmao123xdd•2mo ago

show the product repo and the controller also shos the product class show

ShrutiOP•2mo ago

product repo

YoChrisRapNow•2mo ago

package com.example.EcomTutDemo11.repo; import com.example.EcomTutDemo11.model.Product; import jakarta.persistence.criteria.CriteriaBuilder; import org.springframework.data.jpa.repository.JpaRepository; import org.springframework.stereotype.Repository; @Repository

public interface ProductRepo extends JpaRepository<Product, Integer> {

}

public interface ProductRepo extends JpaRepository<Product, Integer> {

}

This message has been formatted automatically. You can disable this using /preferences.

YoChrisRapNow•2mo ago

service package com.example.EcomTutDemo11.service; import com.example.EcomTutDemo11.model.Product; import com.example.EcomTutDemo11.repo.ProductRepo; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; @Service

public class ProdcutService {
    @Autowired
    private ProductRepo repo;

    public List<Product> getAllProducts(){

        return repo.findAll();
    }

}

public class ProdcutService {
    @Autowired
    private ProductRepo repo;

    public List<Product> getAllProducts(){

        return repo.findAll();
    }

}

This message has been formatted automatically. You can disable this using /preferences.

YoChrisRapNow•2mo ago

model package com.example.EcomTutDemo11.model; import jakarta.persistence.Entity; import jakarta.persistence.Id; import lombok.*; import java.math.BigDecimal; import java.util.Date; @Data @AllArgsConstructor @NoArgsConstructor @Getter @Setter @Entity

public class Product {
    @Id
    private int id;
    private String name;
    private String description;
    private String brand;
    private BigDecimal price;
    private String category;
    private Date releaseDate;
    private boolean available;
    private int quantity;


}

public class Product {
    @Id
    private int id;
    private String name;
    private String description;
    private String brand;
    private BigDecimal price;
    private String category;
    private Date releaseDate;
    private boolean available;
    private int quantity;


}

This message has been formatted automatically. You can disable this using /preferences.

YoChrisRapNow•2mo ago

controller package com.example.EcomTutDemo11.controller; import com.example.EcomTutDemo11.model.Product; import com.example.EcomTutDemo11.service.ProdcutService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import java.util.List; @RestController @RequestMapping("/api")

public class Prodcontroller {

    @Autowired
    private ProdcutService service;
    @GetMapping("/")
    public String g()
    {
        return "hi";
    }

    @GetMapping("/products")
    public List<Product> getAllProducts()
    {
        List<Product> products = service.getAllProducts();
        System.out.println(" API /products was called!");
        System.out.println("Fetched Products: " + products);
        return products;
    }

public class Prodcontroller {

    @Autowired
    private ProdcutService service;
    @GetMapping("/")
    public String g()
    {
        return "hi";
    }

    @GetMapping("/products")
    public List<Product> getAllProducts()
    {
        List<Product> products = service.getAllProducts();
        System.out.println(" API /products was called!");
        System.out.println("Fetched Products: " + products);
        return products;
    }

This message has been formatted automatically. You can disable this using /preferences.

ayylmao123xdd•2mo ago

can you try using any other database than h2 maybe the database itself is the problem beacuse the code looks good oh

public class Product {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

public class Product {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

try adding @Shruti add the generated value annotation to your id and see if it helps

ShrutiOP•2mo ago

i am using h2 only i added this @GeneratedValue(strategy = GenerationType.IDENTITY) but no difference

ayylmao123xdd•2mo ago

h2 database isnt good as a real one its good just for testing @dan1st can you take a look h2 doesnt return objects

dan1st•2mo ago

Can I see the DB configuration (application.properties) and the code inserting objects? If it is an automated test,I'd like to see that as well If applicable, it would be useful to see the content of the relevant table just because SO is down after they've migrated to GCP yesterday?

ShrutiOP•2mo ago

application properties spring.application.name=EcomTutDemo11 server.port=9092 spring.datasource.url=jdbc:h2:mem:ecom sspring.datasource.driver-class-name=org.h2.Driver spring.jpa.hibernate.ddl-auto=update spring.jpa.show-sql=true spring.jpa.defer-datasource-initialization=true data.sql INSERT INTO Product (id, name, description, brand, price, category, release_date, available, quantity) VALUES (1, 'Smartphone', 'Latest model with high performance', 'Samsung', 69999.99, 'Electronics', '2025-04-01', true, 50), (2, 'Laptop', 'Ultra-fast gaming laptop', 'Asus', 129999.99, 'Computers', '2025-03-15', true, 20), (3, 'Headphones', 'Noise-cancelling wireless headphones', 'Sony', 14999.50, 'Accessories', '2025-02-20', true, 100), (4, 'Smartwatch', 'Feature-rich smartwatch with health tracking', 'Apple', 39999.00, 'Wearables', '2025-01-10', true, 30);

ShrutiOP•2mo ago

ShrutiOP•2mo ago

JavaBot•2mo ago

application properties                        spring.application.name=EcomTutDemo11
server.port=9092

spring.datasource.url=jdbc:h2:mem:ecom
sspring.datasource.driver-class-name=org.h2.Driver

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true

spring.jpa.defer-datasource-initialization=true

application properties                        spring.application.name=EcomTutDemo11
server.port=9092

spring.datasource.url=jdbc:h2:mem:ecom
sspring.datasource.driver-class-name=org.h2.Driver

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true

spring.jpa.defer-datasource-initialization=true

data.sql                INSERT INTO Product (id, name, description, brand, price, category, release_date, available, quantity) VALUES
(1, 'Smartphone', 'Latest model with high performance', 'Samsung', 69999.99, 'Electronics', '2025-04-01', true, 50),
(2, 'Laptop', 'Ultra-fast gaming laptop', 'Asus', 129999.99, 'Computers', '2025-03-15', true, 20),
(3, 'Headphones', 'Noise-cancelling wireless headphones', 'Sony', 14999.50, 'Accessories', '2025-02-20', true, 100),
(4, 'Smartwatch', 'Feature-rich smartwatch with health tracking', 'Apple', 39999.00, 'Wearables', '2025-01-10', true, 30);

data.sql                INSERT INTO Product (id, name, description, brand, price, category, release_date, available, quantity) VALUES
(1, 'Smartphone', 'Latest model with high performance', 'Samsung', 69999.99, 'Electronics', '2025-04-01', true, 50),
(2, 'Laptop', 'Ultra-fast gaming laptop', 'Asus', 129999.99, 'Computers', '2025-03-15', true, 20),
(3, 'Headphones', 'Noise-cancelling wireless headphones', 'Sony', 14999.50, 'Accessories', '2025-02-20', true, 100),
(4, 'Smartwatch', 'Feature-rich smartwatch with health tracking', 'Apple', 39999.00, 'Wearables', '2025-01-10', true, 30);

dan1st•2mo ago

oh so you are getting the entries but cannot find anything there wait, is there lombok? yep, it's because of lombok I'd show you my own SO answer but SO is down rn First update to the latest lombok version and then add <proc>full</proc> to the <configuration> of the maven-compiler-plugin @Shruti or don't use lombok if you don't want your application to break lol

ayylmao123xdd•2mo ago

yes lol

dan1st•2mo ago

it's really annoying because I have written a good Stack Overflow answer explaining the issue

ayylmao123xdd•2mo ago

extended april fools joke

dan1st•2mo ago

they migrated their servers to Google Cloud yesterday so take it as you want

ayylmao123xdd•2mo ago

if gpt wasnt a thing all engineers would be doomed

dan1st•2mo ago

though it seems that the other SE sites got issues as well

ShrutiOP•2mo ago

Yeah I used lombok.. previously it was giving mvn not found then I reinstalled everything..then it gave jdk not found because it was pointing to older version..I resolved that and now this ..

dan1st•2mo ago

for old JDK versions, it "works" for newer JDK versions, you need to change the things I mentioned though there are alternatives to <proc>full</proc>

dan1st•2mo ago

for more details: https://stackoverflow.com/a/79210588/10871900

Stack Overflow

Build Failure: @Data Annotation won't regonize by Maven

I consider that my maven has problems with the annotation @Data from lombok. About the project: Java 23 Spring Boot Version 3.3.4 also using Intellij ultimate The error appears after like mvn comp...

ayylmao123xdd•2mo ago

is this tag the replacement for the annotation processor tag in older jdks

dan1st•2mo ago

ayylmao123xdd•2mo ago

or does it have some extra oh ok

dan1st•2mo ago

you can use the annotation processor tag instead -proc:full pretty much means "compile and register annotation processors automatically"

JavaBot•2mo ago

💤 Post marked as dormant

This post has been inactive for over 300 minutes, thus, it has been archived. If your question was not answered yet, feel free to re-open this post or create a new one. In case your post is not getting any attention, you can try to use /help ping. Warning: abusing this will result in moderative actions taken against you.

ShrutiOP•2mo ago

same issue

YoChrisRapNow•2mo ago

i added this @Override

    public String toString() {
        return "Product{id=" + id + ", name='" + name + "', brand='" + brand + "', price=" + price + ", category='" + category + "', quantity=" + quantity + "}";
    } and got results

    public String toString() {
        return "Product{id=" + id + ", name='" + name + "', brand='" + brand + "', price=" + price + ", category='" + category + "', quantity=" + quantity + "}";
    } and got results

This message has been formatted automatically. You can disable this using /preferences.

ShrutiOP•2mo ago

thank you so much

JavaBot•2mo ago

If you are finished with your post, please close it. If you are not, please ignore this message. Note that you will not be able to send further messages here after this post have been closed but you will be able to create new posts.

straightface•2mo ago

@Shruti upload whole pom

ShrutiOP•2mo ago

pom

message.txt

straightface•2mo ago

https://i.sstatic.net/rIgb1.jpg

straightface•2mo ago

do you have this enabled? @Shruti

ShrutiOP•2mo ago

yes i did that already

straightface•2mo ago

Can you try with java 11?

ayylmao123xdd•2mo ago

he said it works already

straightface•2mo ago

Ahh I missed it

JavaBot•2mo ago

💤 Post marked as dormant

This post has been inactive for over 300 minutes, thus, it has been archived. If your question was not answered yet, feel free to re-open this post or create a new one. In case your post is not getting any attention, you can try to use /help ping. Warning: abusing this will result in moderative actions taken against you.

Gaming

Programming

Issue: API Returning Empty JSON Objects {}

Did you find this page helpful?