Is Java appropriate for multi-tenant SAAS architecture?

Question

I'm building a new SAAS architecture and was looking for some advice on the most appropriate language/framework to use.

As far as other languages, it's said the multi-tenancy in grails is pretty mature, and event based NodeJS is also nice. What I concern is the framework availability of workflow, security RBAC, API design, ORM....because the SAAS we're building is business enterprise oriented.

I prefer Java language, Spring framework, workflow, and maybe GWT...But just imagine one day once the SAAS sells well and we have thousands of tenants and high concurrency happens, is Java able to solve hight concurrency I/O cost and can scale-up massively? Or, where can I find a bunch of great material out there about how to design great Java large scale web application architecture? (high-concurrency)

Regardless, given the very high-level description of what I'm trying to achieve, which frameworks would best meet my needs (for the least amount of pain!)
Thanks.

Answer 1

"is Java able to solve high concurrency I/O cost and can scale-up massively"

No language solves these concerns. Skilled, experienced, intelligent software developers do. With any language. That said, yes, Java is routinely used for web apps handling thousands of concurrent customers, across tens or hundreds of machines, dealing with terabytes of data.