Previous answers seem to be outdated.
Java's File.renameTo() is probably the easiest solution for API 7, and seems to work fine.
Be carefull IT DOES NOT THROW EXCEPTIONS, but returns true/false!!!
Note that there seem to be problems with it in previous versions (same as NIO).
If you need to use a previous version, check here.
Here's an example for API7:
File f1= new File("C:\\Users\\.....\\foo");
File f2= new File("C:\\Users\\......\\foo.old");
System.err.println("Result of move:"+f1.renameTo(f2));
System.err.println("Move:" +f1.toURI() +"--->>>>"+f2.toURI());
Path b1=Files.move(f1.toPath(), f2.toPath(), StandardCopyOption.ATOMIC_MOVE ,StandardCopyOption.REPLACE_EXISTING ););