Sorting these Field Values into a Map

Question

I have mostly solved the problem but can't figure out the error trace at the end - it'll be something subtle I'm doing wrong probably.

I'm implementing a workaround for GSON, which has real problems parsing nested maps.

public class RegisterValues
    {
        int Earth;
        int Mars;
            //etc for 200 planets

                public Map returnValues()throws IllegalArgumentException, SecurityException, IllegalAccessException, NoSuchFieldException{
                  final String [] fieldValues = new String[] {"Earth", "Mars", //etc }
                  RegisterValues regValues = new RegisterValues();

                  Map values = new HashMap<String, Integer>();
                  //values.put("Earth", Earth); manually this works, I'd rather loop through a readymade array of String values.


                  for (String value : fieldValues){
                          values.put(field, regValues.getClass().getField(field).getInt(field);) //here it breaks

        }
        return values;
            }
         }

The error trace:

Rebinding example.client.Panel // This is the class that is calling the above function
02:24:31.704 [DEBUG] Checking rule <generate-with class='com.google.gwtjsonrpc.rebind.RemoteJsonServiceProxyGenerator'/>
02:24:31.704 [ERROR] Errors in '.../RegisterValues.java'
02:24:31.704 [ERROR] Line 324: No source code is available for type java.lang.SecurityException; did you forget to inherit a required module?
02:24:31.704 [ERROR] Line 333: The method getField(String) is undefined for the type Class<capture#1-of ? extends RegisterValues>

All the line numbers are referring to the part where I call this class. It works when I fill the map manually, but it doesn't work when I try doing this looping method.

Basically I'm wondering if the above is correct?

Sidenote : If the above looks correct, is it due to this being impossible since this is a reflected class i.e it is compiled on the fly (GWT.create()) only when I access this part of the program - therefore it is having some problem with that?

Basically changing those strings into fieldnames is all I want — fiz, Mar 27 '14 at 17:54

score 2 · Answer 1 · edited May 23 '17 at 10:31

A java.lang.SecurityException is getting thrown to the client side, but it is not compatible with the GWT client side (because client code gets cross-compiled to Javascript).

See this link for a list of Java classes you can use with client-side code: http://www.gwtproject.org/doc/latest/RefJreEmulation.html

It looks like you're calling getField(String) on the client side. That's why [ERROR] Line 333 is happening. If this code is in the server side, make sure the path for this class doesn't have an entry in the .gwt.xml as a source path (eg: make sure <source path='server' /> doesn't exist).

Instead of doing regValues.getClass(), can you try RegisterValues.class? (I'm not sure whether this would make a difference)

Also I'm not sure what you're trying to accomplish, but you can't use Gson on the GWT client side. You can use GWT's AutoBean feature instead: using Gson library in GWT client code

You can use Gson on the server side, and if it doesn't create Maps you can use on the client side, you can write a custom Serializer(com.google.gson.JsonSerializer) and Deserializer(com.google.gson.JsonDeserializer) to build Maps that are usable on the client side.

Sorting these Field Values into a Map

1 Answers1