Servlet responses to upload/download requests

My task is to write a program to store files in object store. One of the subtasks requires to send json or xml format response to the file uploader/downloader as requested by client.

The following rules must be followed:

entry                         
               +-------------------------+             
               v                         v             
           upload                      download        
       +-----------+              +--------------+     
       v           v              v              v     
    succ          err            succ           err    
  +-----+       +-----+                       +-----+  
  v     v       v     v                       v     v  
json1  xml1    json2  xml2                  josn2  xml2

• if user uploads file with success, return json/xml type 1

• if user uploads file with error, return json/xml type 2

• if user downloads file with success, don't change return object

• if user downloads file with error, return json/xml type 2

I've managed to solve the task but I'm not satisfied with the class dependencies and nested if/else-s I have. I think mixture of abstract factory and strategy are suitable for the issue. Can you give me a hint on how I can deal with the problem?

My code snippet:

```
public Result upload(HttpServletRequest request) {
UploadRequestParams uploadParams = UploadRequestParams.getObjectFrom(request);
... // create info object
Result res = handleUploadRequest(uploadParams);

Result result = jsonXml(info, res);
return result;
}

private Result jsonXml(RequestInfo info, Result result) {
Serializer ser;
if ("xml".equals(format)) {
ser = new XmlSerializer();
} else {
ser = new JsonSerializer();
}
Result res = ser.serialize(info, result);

return res;
}

@Override
public Result serialize(RequestInfo info, Result result) { // json implementation
GsonBuild

if (info.isUpload()) {
        if (result.isValid()) {
            wrap = new InfoWrapperImpl1(info, result);
        } else {
            wrap = new InfoWrapperImpl2(info, result);
        }
    } else {
        wrap = new InfoWrapperImpl1(info, result);
    }

Can be written as:

if (!info.isUpload() || result.isValid()) {
        wrap = new InfoWrapperImpl1(info, result);
    } else {
        wrap = new InfoWrapperImpl2(info, result);
    }

Also InfoWrapperImpl1 and InfoWrapperImpl2 are not very good names, as they are not expressive and look quite similar to each other.

StackExchange Code Review Q#82569, answer score: 3