问题
I am extremely new to java (about one week of experience at the moment). I have made a fair amount of simple programs in an older version of eclipse Juno on a PC. I copied all of the files onto a flash drive and put them into the workspace of eclipse kepler on my mac laptop. Now every single line of code is unrecognized and the JRE system library folder is gone from all of the projects. I am not sure how to fix this and I would love if someone will help my noob self at this. Thanks!
回答1:
You have to configure the jre from your mac in eclipse. You find it under window preferences and search for jre. After that, in your eclipse project you can use the new configured jre (project properties - Java Build Path)
Hope this helps.
来源：https://stackoverflow.com/questions/17383205/eclipse-4-3-kepler-missing-jre-system-library