Shouldn't have a problem sending a HashMap back and forth. As far as i can tell GWT has a fairly complete implementation of the Java Collections API, and all of which are Serializable, so there shouldn't be any issues. I haven't used it for much more than Lists so there might be quirks I haven't come across yet.
2010/6/18 Jose Luis Estrella Campaña <[email protected]>: > Hello There ! > > I believe what Chris says is totally right, I should just use a > regular Java Object, I was mistaken when I thought I had to do JSON > parsing on the server side. > Now, I would like to know if a HashMap containing Strings only is > serializable ? Could I send it from the client to the Server and Back > (specially back)? > > Thank you very much in advance ! > > Jose. > > On Jun 17, 10:59 pm, Jan Ehrhardt <[email protected]> wrote: >> The GWT docs are offering you to use the JavaScript "eval" function directly >> or through the JSONParser class, which internally uses the "eval" function. >> A more secure way, that is to use the JSON >> libraryhttp://www.json.org/js.html. You'll place the additional JavaScript >> library >> in your host page, as any other JavaScript too. Than take the code from the >> GWT docs: >> >> private final native JsArray<StockData> asArrayOfStockData(String json) /*-{ >> return *eval(json);* >> >> }-*/; >> >> and modify it like this: >> >> private final native JsArray<StockData> asArrayOfStockData(String json) /*-{ >> return *$wnd.JSON.parse(json);* >> >> }-*/; >> >> This is more secure than using the "eval" function. Additionally the >> "JSON.parse()" function has become part of the JavaScript standard and is >> implemented natively in many modern browsers. The above library knows this >> and delegates the secure JSON parsing to the fast native parser provided by >> the browser. >> >> Regards >> Jan Ehrhardt >> >> 2010/6/18 Chris Boertien <[email protected]> >> >> >> >> > Is there a particular reason that you _need_ the JSON string? If your >> > using GWT RPC then you can simply send a Java Object to the server and >> > the underlying GWT will handle the serialization for you. >> >> > If you the JSON string is coming from somewhere else and you really >> > have no choice, then it may be worthwhile to put together a JSO >> > Overlay, use the Overlay to instantiate a POJO on the client side >> > code, and send the POJO to the server via GWT RPC. >> >> > Since your new some of that probably makes no sense, and If you can >> > give a little more detail as to why you need to have JSON originating >> > from the client I'm sure this can be explained a bit better to fit >> > your case. >> >> > GWT-RPC:http://code.google.com/webtoolkit/doc/latest/tutorial/RPC.html >> > GWT-JSON: >> >http://code.google.com/webtoolkit/doc/latest/tutorial/JSON.html#client >> >> > 2010/6/16 Jose Luis Estrella Campaña <[email protected]>: >> > > Hello Folks ! >> >> > > I'm glad to say that I'm a brand new user of GWT, a very happy one by >> > > the way. However, as any newcomer I have questions, One in particular. >> > > Here it goes: >> >> > > What's the easiest, most straight forward way to deserialize a JSON >> > > String on the Server side and instance a Java Object from it ? >> >> > > The JSON String will be sent from the client side, an implementation >> > > of the RemoteService for example, and I intend to deserialize it on >> > > the Server side, say inside the RemoteServiceServlet Implementation, >> > > so I can instance a Java Object with the information contained in the >> > > JSON string afterwards. Is there a way this last step automatically >> > > with some GWT API ? >> >> > > I would like to see some examples if it's possible. >> >> > > Best Regards, >> >> > > Sincerely, >> >> > > Jose. >> >> > > -- >> > > You received this message because you are subscribed to the Google Groups >> > "Google Web Toolkit" group. >> > > To post to this group, send email to [email protected] >> > . >> > > To unsubscribe from this group, send email to >> > [email protected]<google-web-toolkit%2Bunsubs >> > [email protected]> >> > . >> > > For more options, visit this group at >> >http://groups.google.com/group/google-web-toolkit?hl=en. >> >> > -- >> > You received this message because you are subscribed to the Google Groups >> > "Google Web Toolkit" group. >> > To post to this group, send email to [email protected]. >> > To unsubscribe from this group, send email to >> > [email protected]<google-web-toolkit%2Bunsubs >> > [email protected]> >> > . >> > For more options, visit this group at >> >http://groups.google.com/group/google-web-toolkit?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "Google Web Toolkit" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/google-web-toolkit?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
