public class Test {
    public static void main (String args[]) throws IOException {
        for(int i = 0; i < 10; i++) {
            for(int j = 0; j < 10; j++) {
                PrintWriter writer = new PrintWriter("/Users/me/testingStuff/" + String.valueOf(i) + "_" + String.valueOf(j) + "_.txt", "UTF-8");
                writer.write("yo");
            }
        }
    }
}