Gson Json Parsing in Java

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I want to parse json list. I have used springboot project, database is H2. Database contains few data.

I have successfully displayed json data via @getmapping function. Code is as below,

File-----> ProductController.Java 
@GetMapping("/products_from_db")
        public  List<Product> getProducts_from_db() { 
            return productservice.findAll() ;
        }

Second File is as Follows.

File ----> Product.java

@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
//@ToString
@Entity
public class Product {

    @Id
    @GeneratedValue
    private Integer id;
    private String name;
    private int price;

    @Override
    public String toString() {
        return "Product{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", price=" + price +
                '}';
    }

output:

[{
    "id": 1,
    "name": "Mango",
    "price": 98
}, {
    "id": 2,
    "name": "Strawberry",
    "price": 92
}, {
    "id": 3,
    "name": "Cadbury",
    "price": 85
}, {
    "id": 4,
    "name": "yash",
    "price": 100
}]

I want to display only name and price in back end code only.

spring-boot gson parsing json java
1 Answers

Unfortunately Gson isn't as straight forward in certain aspects as, for example, Jackson - where you can simply use the annotation @JsonIgnore.

On the other hand, Gson seems to have more flexibility (although a little too technical sometimes.)

In the case of Gson you have two main options to achieve what you want:

  1. Mark the field you want to ignore as transient: private transient String id (in this case you have to make sure that this won't cause any side effects in your application.)

  2. You can use the very flexible capabilities of Gson, especially the annotation @Expose. for example:

    @Expose(Serialize = false) private String id;

You can find more examples and details here and here.

Please, let us know if it helps.

user_24572510
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