Google App Engine（GAE）上的ThreadLocal

Question

I would like to make some request-wide data available in my app engine application.

Examples:

• The URL for which the request was made.
• Authentication information.

I see that ThreadLocal is on GAE's JRE whitelist .

Is ThreadLocal a good and safe way to make this information available? Are there alternative / better / more accepted ways?

Answer 1

Yes, it is an accepted practice to store these things in a ThreadLocal . However, a more preferable approach is to pass these values around (as method arguments) wherever they are needed, instead of reaching for them. It's more preferable, because it's more testable at least.