I am trying to use notepad++ as my all-in-one tool edit, run, compile etc.

I have jre installed, i have setup my path variable to .../bin directory.

When I run my "Hello world" in notepad++ , I get this message:

java.lang.UnsupportedClassVersionError: test_hello_world :
 Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(Unknown Source)
       ......................................... 

I think the problem here is about versions, some version of java may be old or too new.

1. how do i fix it?

2. should i install jdk , and setup my path variable to JDK instead of jre?

3. difference between PATH variable in jre or jdk?