spring boot @RequstBody convert blank string to zero of long-CodePudding

ajax send json like

{
  "id":"123123"
  "parentId":"",
},

java class is:

public class Page{
  private Long id;
  private Long parentId;
}

as default, i get
{
  "id":123123
  "parentId":null
}

but i want parentId to be zero, what should i do ? thanks very much

CodePudding user response：

You should be able to initialise the default value, it will automatically assign that instead.

@JsonInclude(
  value = JsonInclude.Include.NON_EMPTY,
  content = JsonInclude.Include.NON_EMPTY)
public class Page {
  private long id = 0;
  private long parentId = 0;
}

CodePudding user response：

If initializing the attribute in the Page class is not feasible or you also don't want to change the attribute from Long to long then you can implement a custom Jackson deserializer as follows:

public class CustomLongDeserializer extends JsonDeserializer<Long> {

    @Override
    public Long deserialize(JsonParser jp, DeserializationContext ctxt) 
      throws IOException, JsonProcessingException {

        String text = jp.getText();
        if (text == null || text.isEmpty()) {
            return 0;
        } else {
            return Long.valueOf(text);
        }
    }
}

Then you just need to configure its usage on the respective attribute:

public class Page{
  private Long id;
  
  @JsonDeserialize(using = CustomLongDeserializer.class)
  private Long parentId;
}