The content of your error response (issue with the NIC) leads me to believe there is something essential missing.
Have you confirmed you can access the db using the same creds from a different tool? (I.e. using some db interrogation tool like sqldeveloper/toad/dbvisualiser?
Depending if you have oracle installed locally the apps will default to try and use the tnsnames.ora file (toad and sqldeveloper do this by default if memory serves), but dbvisualiser allows you to use the jdbc thin driver connection string you need. If you download and setup and test the connection in another tool will confirm the problem is a soapui problem or not.
Also. Have you confirmed the jdbc .jar file youre using is correct relative to the version of oracle db you are trying to connect to?
Have you ensured youre using the correct jdk version relative to the version of oracle you are trying to connect to?
The version of .jar file you use is peculiar to the version of java (jdk), which is peculiar to oracle db version you are trying to connect to.
Also the java environment variables (classpath, java_home, path)which indicates to the operating system where to look to run your runtime needs to be correct? If you have multiple instances of jdk/jre installed, you might be executing the wrong runtime. To check this,run a commandprompt and execute 'java -version' at the prompt.
So things to check
1. Can you connect to db from another tool (dbvisualiser) with your current jdbc connectiom details?
2. Oracle version's supported java version (jdk v1.8?) 3. Jdbc .jar file version matches the java version required by your oracle instance 4. Classpath, java_home, path environment variables need to point to the correct version of jdk
Above points are a fair start to check....option one will give us a good start...it will confirm if theres general connectiom problem rather than it being specific to soapui....error response looks like a general connection problem, although this could be a mistake