Question

I am developing a GWT app and I would like to improve the performance of string building. I would like to use the StringBuffer provided by GWT, but I am not sure how to access it. I already have the gwt-user.jar, and it looks like the emul sources are inside, but how can I use them in my IDE(eclipse)?

Answer 1

The emulated sources are the replacement for real Java implementations. They are used all the time, i.e., when you write java.lang.StringBuilder in your GWT client code, GWT actually substitutes the emulated class from `gwt-user.jar/super/com/google/gwt/emul/java/lang.

Basically, you just need to use whatever you want to use, as you would use it in Java, and an emulated class will be substituted as necessary. Of course, limitations apply: if it is not implemented in the emulated GWT code, you can’t use it (String.format is an example).