Web page localization methods

I have a simple web application I am building using Java, Spring-MVC and AngularJS. I want to enable the user to select a language and display the page in the selected language (I'll create the content, in the relevant languages, there's no need for translation).

I have 2 thoughts on how to achieve that, and I was woundering Which is better SEO wise.

My first thought was to user angular js, create a LanguageController which will have a convert(stringToTranslate, lang) function, that will send the string to translate to a REST service that will return the translation in the relevant language for each key. So depanding on lang variable, the whole page be translated to the selected lanaguage, My Concern is what impact this solution would have on SEO? as in order to get the content of the page javaScript code (or angular to be more specific) needs to be rendered, wouldnt that mean that the content of the page won't be indexed at all?

My second thought was to use spring's I18n which I'm currently learning about.

So to summerize my question, how would both methods behave in regards to SEO?

Is there any best practice / alterative that makes more sense, for multi language page support?.