how to parse xml string into class with genericity

[kiritokun07]

how to parse xml string into class with genericity

[joehni]

Now your class members have the exact type and XStream knows what to do.

[joehni]

First of all XStream is from Java to XML and back. So if you look at the XML that is generated by instance if your class, you will recognize, that XStream adds an attribute class with the real class name of the member instance. This is the key information XStream requires for deserialization.

Your class ABC is defined to keep two members of type java.lang.Object. This is what the Java compiler does here with your generic types. Since the actual types of the instances are not equal at runtime, XStream writes the required attribute. Without it, there's absolutely no information what type of object must be generated at deserialization.

The only thing you can do is to write a custom converter for ABC and handle the XML structure for req and resp for yourself. Maybe you can detect at deserialization from your data yourself which instance actually has to be generated. For XStream this will not be possible automagically.

[kiritokun07]

Finally I use inheritance to solve my problem.I extract req and resp in my subclass.It's works.

@Data
@XStreamAlias("ABC")
class ABC {
    private String p1;
    private String p2;
}

@Data
@EqualsAndHashCode(callSuper = true)
class MyBusiness extend ABC {
    private MyBusinessReq req;
    private MyBusinessResp resp;
}

public static <T> T readXmlStr(String xml,T businessClazz){
            XStream xStream = new XStream() {
            //ignore unnecessary properties in xml
            @Override
            protected MapperWrapper wrapMapper(MapperWrapper next) {
                return new MapperWrapper(next) {
                    @Override
                    public boolean shouldSerializeMember(Class definedIn, String fieldName) {
                        if (definedIn == Object.class) {
                            return false;
                        }
                        return super.shouldSerializeMember(definedIn, fieldName);
                    }
                };
            }
        };

     xStream.autodetectAnnotations(true);
     xStream.alias("ABC", businessClazz);
     xStream.allowTypes(new Class[]{businessClazz});
    T business = (T) xStream.fromXML(xml);
    sout(JSON.toJSONString(business));
    return business;
}

public static void testReadXmlStr(){
    String xml = "";
    MyBusiness myBusiness = readXmlStr(xml, MyBusiness.class);
}