How to set up the path in newBufferWriter

How can i set up the path right to newBufferWriter. I'm getting the example usage of the newBufferWriter from oracle page:

Charset charset = Charset.forName("US-ASCII");
String s = ...;
try (BufferedWriter writer = Files.newBufferedWriter(file, charset)) {
    writer.write(s, 0, s.length());
} catch (IOException x) {
    System.err.format("开发者_如何学GoIOException: %s%n", x);
}

I'm comfused how to set the file parameter, Where should i get the Path object, for example i want to create file in a directory , so i have to set a Path object, and in this code the path object is file parameter so , how to give it a string value ? or how to give it any value of a directory where i want to create a certain file ?

And something else, what about that exception ? What does it mean ?

Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: java/nio/file/Path

If you are getting a NoClassDefFoundError for java.nio.file.Path then there is something wrong with your Java environment. You are most likely mixing Java versions; compiling with JDK 7, but trying to run on Java 6 or older. What do you get when you type java -version?

Path in Java 7 is more or less the replacement for File in Java 6 and older.

You can get a Path like this:

Path file = Paths.get("myfile.txt");