Error running spoon on Ubuntu 14.04 64 bit

I am using Spoon tool of Pentaho data integration for long and it was working fine on my system. But since i moved it to /opt I am unable to run again . I have Oracle Java 8 installed on my system and each time try to run it i am end up with following exception

Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/swt/widgets/Composite
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2688)
at java.lang.Class.getMethod0(Class.java:2937)
at java.lang.Class.getMethod(Class.java:1771)
at org.pentaho.commons.launcher.Launcher.main(Launcher.java:149)
Caused by: java.lang.ClassNotFoundException: org.eclipse.swt.widgets.Composite
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 5 more

please help me to resolve this error i haven't found any solution yet

I found a solution to this problem I have removed all hidden directories generated by Kettle as well as its copy from /opt . Then I have extracted new version copy . after that I have added /opt/data-integration to my path variable and I have tried to run it from my home . Although it was not a successful run but it has generated all those dependent hidden folders required to run it . then I have to go to that directory by issuing

cd /opt/data-integration

and then I was successful to run it by issuing

sh spoon.sh

I have to go to that directory because Pentaho developers has set it so by placing relative path to launcher folder in their main command at spoon.sh.