I am new to Ubuntu. I am trying to make a simple Java swing app(lets call it foo) that displays a hello message followed by a user name.I am using Eclipse .Till here everything works fine.When I press the "Run" button my app shows app without a problem.Now I export my app as a runnable jar but when I try to double click the generated jar to execute the following message:

```
Blocked: /usr/bin/java -jar
The file 'home/user/java projects/foo.jar' is not marked as executable.

```

However if I run this jar in windows I get no error.
Any ideas how to solve the problem?I would like a detailed answer if possible.

Thanks in advance :)