GWT/java and javascript

can i design my web pages in html and css instead of java methods and use gwt only in parts of page that i need ajax? and which on开发者_开发技巧e is better gwt, extgwt, vaadin(it run apps in server-side.can i also use it in client-side?), etc...? do i also need to know javascript for using gwt? thanks

can i design my web pages in html and css instead of java methods and use gwt only in parts of page that i need ajax?

Yes, you can. You can create a div on your HTML page and insert your GWT widget there.

which one is better gwt, extgwt, vaadin(it run apps in server-side.can i also use it in client-side?)

I don't know about vaadin but Ext-GWT is a set of ready made components to use with GWT which make your life easier especially if you want to build an web app that looks and feels like a desktop application.

do i also need to know javascript for using gwt?

No, it can be useful sometimes but is not necessary.