no String-argument constructor/factory method to deserialize from String value - Exception while deserializing json object from restTemplate

user_5973573 0
Viewed 47169

Facing issue while making call to retrieve a json response and parse it.

[
    {
        "name": "john doe",
        "age": "24",
        "address": "{\"state\":\"LA\",\"country\":\"US\"}"
    }
]

Models:

Person.java

@Data
@NoArgsConstructor
@JsonIgnoreProperties(ignoreUnknown = true) 
public class Person {
    private String name;
    private String age;
    private Address address;
}

Address .java

@Data
@NoArgsConstructor
@JsonIgnoreProperties(ignoreUnknown = true) 
public class Address {
    private String state;
    private String country;
}

Code to read this data,

ResponseEntity<List<Person>> response = restTemplate.exchange(builder.toUriString(), HttpMethod.GET,requestEntity,new ParameterizedTypeReference<List<Person>>() {});

However i get below exception,

RestClientException while invoking ABS ServiceError while extracting response for type [java.util.List<com.bp.model.Person>] and content type [application/json;charset=UTF-8]; nested exception is org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot construct instance of com.bp.model.Address (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('{"state":"LA","country":"US"}'); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of com.bp.model.Address (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('{"state":"IN","brand":"anthem"}') at [Source: (PushbackInputStream); line: 1, column: 325] (through reference chain: java.util.ArrayList[0]->com.bp.model.Person["address"])

resttemplate deserialization jackson json java
2 Answers

The code is correct but there's a problem with the JSON. The address is a string and not a JSON object. For it to work, it would need to be something like:

"address": {"state": "LA", "country": "US"}

Without the outer quotes and the escape characters.

user_12208020

Here we can try to set the values during runtime.

@JsonProperty("address")
    public void setCustomAddress(String addressFromJson){
        this.address = new Gson().fromJson(addressFromJson, Address.class);
    }
user_200460250
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