New to Java

String[] courseObjects = new String[3];
		File courses = new File("courses.txt");
		BufferedReader in = null;

		try
		{
			in = new BufferedReader(
			new FileReader(courses));

			for (int i = 0; i < courseObjects.length; i++)
			{
			    courseObjects[i] = in.readLine();
			}

			in.close();
		}
			catch(IOException ioe)
			{
				System.out.println(ioe);
			}

			int n = -1;

		String[] classCode = new String[3];

		for(int i = 0; i < courseObjects.length; i++)
		{
			String classCode[i] = courseObjects.substring(0, 6);

		}
the second for loop doesn't seem to be working for me.. i know i'm probably doing something wrong.
basically, i want to get a substring from a string in the courseObjects array and put it into the classCode element.
what am i doing wrong?