Java using so much CPU

[SuperKid]

Is my java being abnormal and using too much CPU? I am playing Minecraft on my Mac and the CPU usage is always constantly high. I am using iStat Menus and got i7 3.4ghz CPU in my iMac.

 

 

Also earlier I was running Netbeans which uses Java at the same time because I use it for my IDE when programming and noticed Java spawned loads of times with almost 100% CPU on each instance and it was then lagging my machine.

 

 

I use Java 7, no idea why it uses so much CPU I am curious to if anyone else see's it use this much CPU?