CODEWITHSUNDEEP
javagenericsjacksondeserializationjackson-databind
CustardBun
CustardBun

Reputation: 3857

Deserializing or serializing any type of object using Jackson ObjectMapper and handling exceptions

I currently have this code I am trying to refactor in order to allow for more possible class types (simplified with dummy code, but the gist is the same):

private String serializeSomething(final SomeSpecificClass something) {
    try {
        return mapper.writeValueAsString(someething);
    } catch (final IOException e) {
        throw new SomeCustomException("blah", e);
    }
}

private SomeSpecificClass deserializeSomething(final String payload) {
    try {
        return mapper.readValue(payload, SomeSpecificClass.class);
    } catch (final IOException e) {
        // do special things here
        throw new SomeCustomException("blah", e);
    }
}

We recently found out that we will probably have to accept other types here, not just SomeSpecificClass. Is there a better way of doing this without having to change everything to Object instead of SomeSpecificClass? So that we can return the right type in deserializeSomething (and not have to cast it after we get the return value from the caller)?

Upvotes: 2

Views: 1896

Answers (1)

Michał Ziober
Michał Ziober

Reputation: 38655

Start from example implementation:

class JsonObjectConverter {

    private ObjectMapper mapper = new ObjectMapper();

    public String serialiseToJson(Object value) {
        try {
            return mapper.writeValueAsString(value);
        } catch (JsonProcessingException e) {
            throw new IllegalArgumentException("Could not serialise: " + value, e);
        }
    }

    public <T> T deserialiseFromJson(String json, Class<T> clazz) {
        try {
            return mapper.readValue(json, clazz);
        } catch (IOException e) {
            throw new IllegalArgumentException("Could not deserialize: " + clazz, e);
        }
    }

    public SomeSpecificClass deserialiseToSomeSpecificClass(String json) {
        return deserialiseFromJson(json, SomeSpecificClass.class);
    }
}

You can write two general methods: serialiseToJson and deserialiseFromJson which can serialise any type to JSON and deserialise JSON payload to given Class. You can implement of course some extra methods for most common and most used classes like deserialiseToSomeSpecificClass. You can write as many method as you need in this format: deserialiseToXYZ.

Upvotes: 2

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