My eclipse neon running the exact previous snapshot of Java code

Question

I am using eclipse neon 4.6.3 in ubuntu 14.04. Suddenly today I have noticed that it is compiling and running the immediate previous snapshot of the code.

For example, I had a code like this:

System.out.println("1");

After running this if I change it like this:

System.out.println("2");

It will print: 1

That means it is running the previous runned snapshot of the code. As a result I have to run every program twice to observe the output.

I have tried to open new project, delete previous projects, restart eclipse etc. Nothing worked. However, when I run python scripts in eclipse, that works fine.

Anybody has any idea?

Thanks in advance

Edit: When I go to Window > Preferences > Launch it shows this:

May be this will be helpful to find out the problem.

Answer 1

It is solved.

Go to Window > Preferences > Launching

Check the General option: Build (if required) before launching

Then it will be ok.

Thank you all for trying to help me.