Jax-RS MessageBodyReader [英] Jax-RS MessageBodyReader

问题描述

我正在学习MessageBodyReader方法如何从提供程序中工作。我看到该方法返回一个对象，我不知道如何从服务访问该对象。我可以获得如何从读者类返回对象的解释吗？这将有助于我为所有dto应用阅读规则。提前致谢！

I'm learning how the MessageBodyReader method works from the providers. I see the method returns an object and I'm not sure how to access the object from a service. Could I get an explanation on how to get the object returned from the reader class? This would help me apply a reading rule for all dto's. Thanks in advance!

服务：

    @POST
    @Produces({ MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON })
    @Path("/CreateAccount")
    @Consumes({ MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON })
    public Response createAccount(@Context HttpServletRequest req) {

        String a = "Reader success? ";//Would to see that string here!
        return Response.ok().build();
    }

提供商：

@Provider
public class readerClass implements MessageBodyReader<Object>
{

@Override
public boolean isReadable(Class<?> paramClass, Type paramType,
        Annotation[] paramArrayOfAnnotation, MediaType paramMediaType) {
    // TODO Auto-generated method stub
    return true;
}

@Override
public Object readFrom(Class<Object> paramClass, Type paramType,
        Annotation[] paramArrayOfAnnotation, MediaType paramMediaType,
        MultivaluedMap<String, String> paramMultivaluedMap,
        InputStream paramInputStream) throws IOException,
        WebApplicationException {
    // TODO Auto-generated method stub

    return "Successfully read from a providers reader method";
}

}

推荐答案

您误解了MessageBodyReader的用途，它用于以下目的：

You misunderstood the purpose MessageBodyReader , it is used for the following purpose :

支持转换流的提供商的合同到
Java类型。要添加MessageBodyReader实现，请使用@Provider注释
实现类。 MessageBodyReader
实现可以使用Consumes进行注释，以限制媒体
类型，它们被认为是合适的

Contract for a provider that supports the conversion of a stream to a Java type. To add a MessageBodyReader implementation, annotate the implementation class with @Provider. A MessageBodyReader implementation may be annotated with Consumes to restrict the media types for which it will be considered suitable

示例：
如果您有一个用例来自xml / json以外的自定义格式，您想提供自己的UnMarshaller，您可以使用messagebody reader

Example : If you have a use case where you getting come custom format other than xml/json ,you want to provide your own UnMarshaller you can use messagebody reader

    @Provider
    @Consumes("customformat")
    public class CustomUnmarshaller implements MessageBodyReader {

        @Override
        public boolean isReadable(Class aClass, Type type, Annotation[] annotations, MediaType mediaType) {
            return true;
        }


        @Override
        public Object readFrom(Class aClass, Type type, Annotation[] annotations, MediaType mediaType, MultivaluedMap multivaluedMap, InputStream inputStream) throws IOException, WebApplicationException {
            Object result = null;
            try {
                result = unmarshall(inputStream, aClass); // un marshall custom format to java object here
            } catch (Exception e) {
                e.printStackTrace();
            }

            return result;


}
}

在网络服务中你可以使用这个... ..

In webservice you can use this like ..

    @POST    
    @Path("/CreateAccount")
    @Consumes("custom format")
    public Response createAccount(@Context HttpServletRequest req,Account acc) {

        saveAccount(acc); // here acc object is returned from your custom unmarshaller 
        return Response.ok().build();
    }

更多信息：
自定义编组/卸载示例，
Jersy Entity Providers教程

这篇关于Jax-RS MessageBodyReader的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！