Question: Is there a way to measure the cyclomatic complexity for Java classes by giving the compiled file `.class` of the Java class? 

What I mean is that how can I measure the cyclomatic complexity based on the `.class` file only?

If that is **difficult to do**, how can I then measure the cyclomatic complexity in Eclipse Oxygen.3a Release (4.7.3a)?

Answer: 
Cyclomatic complexity is measure of the quality of the code that shows how easy it will be for reading, understanding and maintenance. So you should measure this on the real Java code, not of the compiled one. Nobody is going to read the compiled source code so it shouldn't be easy for maintenance.

Also you should expect that the already compiled class will have a lot of changes and optimisations so the data you receive will be different from the cyclomatic complexity of the original source code.
We have plugins like CodeCity which calculates the cyclomatic complexity for the .java file you choose.