How parse nested escaped json with Jackson?

问题

Consider json:

{
    "name": "myName",
    "myNestedJson": "{\"key\":\"value\"}"
}

Should be parsed into classes:

public class MyDto {
    String name;
    Attributes myNestedJson;

}

public class Attributes {
    String key;
}

Can it be parsed without writing stream parser? (Note that myNestedJson contains json escaped json string)

回答1:

I think you can add a constructor to Attributes that takes a String

class Attributes {
    String key;

    public Attributes() {}

    public Attributes(String s) {
        // Here, s is {"key":"value"} you can parse it into an Attributes
        // (this will use the no-arg constructor)
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            Attributes a = objectMapper.readValue(s, Attributes.class);
            this.key = a.key;
        } catch(Exception e) {/*handle that*/}
    }

    // GETTERS/SETTERS  
}

Then you can parse it this way:

ObjectMapper objectMapper = new ObjectMapper();
MyDto myDto = objectMapper.readValue(json, MyDto.class);

This is a little dirty but your original JSON is too :)

来源：https://stackoverflow.com/questions/54531391/how-parse-nested-escaped-json-with-jackson