
Here is a graph comparing java and C++ performance on various algorithms. It can be seen that java is faster in most cases.
Though these benchmarks show that java is faster, still java programs appear to be slow.This is mainly because large applications are deployed as jar files, and when loading the application the java classloader as to extract the classes from the compressed jar files and then do verification and the load the class. Once a class is loaded it will actually be faster than C code.