Solved Eclipse won't compile with the right Java!

Hello! I've been really frustrated for about an hour now, so please, do not tell me I didn't do research, that is really all I have been doing for the last hour.

When I try building my plugin, I get this error:
Fatal error compiling: tools.jar not found

This just started happening, it wasn't happening 2 hours ago...
I've purged Java 6 and Java 8, so there is no problem with that, my Java_Home is set correctly, because when I do java -version in terminal, I get: java version "1.7.0_21".

I've deleted every JDK and JRE in my eclipse > Window > preferences > Java > Installed JREs except for java-7-openjdk-amd64. It's located in /usr/lib/jvm/java-1.7.0-openjdk-amd64/jre, what am I doing wrong! I have been pulling my hair over this, please help!

 

Point eclipse at the jdk not the jre

 

Hello Sagacious_Zed , thanks for your reply! So, does this mean that java-7-openjdk-amd64 is actually the JRE, not the JDK? Why is it named openjdk when it only has a jre folder? I will go ahead and try installing Java 7 JDK now, hopefully it turns out correctly. Once again, thanks for replying!

Sagacious_Zed
Hoooray! You're the best Sagacious! I wouldn't have thought of reinstalling java JDK, I'm really sorry for such a stupid problem! I followed this tutorial for anyone that is stuck in this same ditch: http://www.liberiangeek.net/2012/04/install-oracle-java-jdk-7-in-ubuntu-12-04-precise-pangolin/

EDIT by Moderator: merged posts, please use the edit button instead of double posting.