Jackson Converting String to Object

Question

Link.java

@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({ "rel", "href","method" })
public class Link {

    @JsonProperty("rel")
    private String rel;
    @JsonProperty("href")
    private String href;
    @JsonProperty("method")
    private Method method;

    @Override
    public String toString() {
        return ToStringBuilder.reflectionToString(this);
    }
}

I have this third party class with fasterxml jackson annotations. I can convert a given object into a string using the specified toString() method. Is there any way of using that String to get an object of type Link?

Note: The object itself has an embedded object (which has several more embedded objects) and these too needs to be converted into a Method object from the string itself.

Colene

don't use toString Use jackson ObjectMapper::readValue and ObjectMapper::writeValueAsString – Extradite

Use new ObjectMapper().readValue(jsonString, Link.class); – Frigate

@Extradite ... although ToStringBuilder can be configured to output JSON, which ObjectMapper would be able to consume. – Rapid

yes you can but there are cases where toString() performs very badly expecially in cases of nested objects and collections.Try printing a map or list with toString and also with ObjectMapper and see the difference – Extradite

Answer 1

Just putting the comment by @pvpkiran in an answer.

Use ObjectMapper class from com.fasterxml.jackson.databind

ObjectMapper objectMapper = new ObjectMapper();

Converting from Object to String:

String jsonString = objectMapper.writeValueAsString(link);

Converting from String to Object:

Link link = objectMapper.readValue(jsonString, type)

Colene

we can also call like this String jsonString = objectMapper.writeValueAsString(Object); – Ponder

what if don't know what is the class type? – Spacesuit

Java can't ascertain the class type magically? You can have ton of Classes which could possibly fit it – Zenia