My auto activation keys are set to a to z. Thus once I type str, it proposes StringBuilder, which is what I want. 

Then, I press Space to accept the suggestion, and type sb for the variable name. Eclipse shows Non-Type proposals "sBuilder". Since I have decided the variable name to be sb, the Non-Type proposals are useless.

As the annoying proposal shows, I cannot continue to type =, because Eclipse will change my variable name from sb to sBuilder. So I have to press Esc, then =.
Every time I define variables, Eclipse always gives me Non-Type proposals, which costs one Esc to reject. How to disable Non-Type proposals in Eclipse??
Try this:
Window - Preferences.Java - Editor - Content Assists - Advanced.Java Proposals should be checked by default. Java Proposals consists of both Non-type and Type proposals.Non Type Proposal, uncheck the Java Proposals and Java Non-Type Proposals, then check the Java Type Proposals.If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With