All the preceding advise on getting out of jury duty is good but not foolproof. No dismissal is automatic and no excuse is automatically valid for a dismissal.

I've been called 12 times in the last 25 years and actually served on 3 juries and one of those was while I was an active duty law enforcement officer. I have no idea why I wasn't dismissed from that one.

In Cali you must show up on the first day then call in after 7pm every day after that for a week to see if you have been empaneled. Pretty easy as far as public service goes.
If empaneled, rarely does it last longer then 2 weeks.

Jury service is your civic duty as an American. For most, it's the only opportunity to participate in the Judicial branch of government. You, along with your fellow jurors, have the ability to decide the fate of another human being. It's an awesome and sobering responsibility and should be taken seriously. Not as an annoyance to be avoided.

Ignoring a summons can and usually does result in a bench warrant. Which makes a nice surprise next time you get pulled over for a minor traffic infraction. I used to love cuffing soccer moms in front of their kids over this one. "Sorry son, but your mom has $10,000 in failure to appear notices."

Just do it. It's simple and easy and your duty as a citizen. Be a contributing member to society.