如何在Restlet中注册Jackson Jdk8模块

Question

是否可以jackson-datatype-jdk8在Restlet org.restlet.ext.jackson扩展包中注册该模块？我需要利用这个新Optional功能.我的猜测是它应该可以通过转换器服务(getConverterService())来访问,但是我在文档中找不到任何可以确定如何设置模块的内容.

Answer 1

我最终从各种来源拼凑出一个与Restlet 2.3一起使用的答案.我的猜测是,这将被重构为Restlet 3,它不适用于版本<2.3,因此请注意,此解决方案很可能具有有限的保质期.

第一步是创建一个自定义Jackson转换器,它实现您拥有的任何自定义要求:

public class CustomJacksonConverter extends JacksonConverter { 
    @Override 
    protected <T> JacksonRepresentation<T> create(MediaType mediaType, T source) { 
        ObjectMapper mapper = createMapper(); 
        JacksonRepresentation<T> jr = new JacksonRepresentation<T>(mediaType, source); 
        jr.setObjectMapper(mapper); 
        return jr; 
    } 

    @Override 
    protected <T> JacksonRepresentation<T> create(Representation source, Class<T> objectClass) { 
        ObjectMapper mapper = createMapper(); 
        JacksonRepresentation<T> jr = new JacksonRepresentation<T>(source, objectClass); 
        jr.setObjectMapper(mapper); 
        return jr; 
    } 


    private ObjectMapper createMapper() { 
        JsonFactory jsonFactory = new JsonFactory(); 
        jsonFactory.configure(JsonGenerator.Feature.AUTO_CLOSE_TARGET, false); 
        ObjectMapper mapper = new ObjectMapper(jsonFactory); 
        mapper.registerModule(new Jdk8Module()); 
        return mapper; 
    } 

} 

然后,您需要创建一种用新副本替换默认Jackson转换器的方法:

static void replaceConverter(
            Class<? extends ConverterHelper> converterClass,
            ConverterHelper newConverter) {

        ConverterHelper oldConverter = null;

        List<ConverterHelper> converters = Engine.getInstance().getRegisteredConverters();
        for (ConverterHelper converter : converters) {
            if (converter.getClass().equals(converterClass)) {
                converters.remove(converter);
                oldConverter = converter;
                break;
            }
        }

        converters.add(newConverter);
    }

您现在可以在入站根中替换转换器:

replaceConverter(JacksonConverter.class, new CustomJacksonConverter());