Currently i am using yFiles Flex to generate diagrams and graphs for clients with Java back-end. I have to migrate my project to the yFiles HTML. Is it possible?
(Note: Short answer because you included literally no detail at all. Please contact the yWorks support team at the e-mail address noted in the readme and mention a bit more about what features you're using so far so that we can help you better.)
Yes, it's possible. I suspect you're currently using a Java server component generating GraphML for a client that's currently using yFiles FLEX and want to migrate the client solution to yFiles for HTML.
Generally you might want to consider a different format for exchanging the graphs between server and client, as the GraphML dialects of yFiles for Java, yFiles FLEX, and yFiles for HTML are not compatible (the graph structure survives, but style and placement information does not). Often a simple JSON format is easier to work with in yFiles for HTML if not all bells and whistles of GraphML are needed. yFiles for HTML may also already be capable of running your layouts directly on the client which might make a server component (just for layout) obsolete as well. Performance is adequate to very good in current browsers unless you have very large graphs.
The API of yFiles for HTML is similar to yFiles FLEX, although the two products are from very different times by now, so there have been extensive changes. Depending on how much customization you have migrating the code may take a while. But generally there should be nothing that's impossible to replicate in yFiles for HTML.