public static void main (String[] args) {
		
		File fi = new File("aa.txt");
		if (fi.exists()) {
			//fi.delete();
			System.out.println("File aa.txt exists");
		}
		if (!fi.exists()) {
			try {
				fi.createNewFile();
				System.out.println("File aa.txt has been created");
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		
		File fo = new File("bb.txt");
		if (fo.exists()) {
			fo.delete();
			System.out.println("File bb.txt has been deleted");
		}
		if (!fo.exists()) {
			try {
				fo.createNewFile();
				System.out.println("File bb.txt has been created");
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		
		InputStream is = null;
		OutputStream os = null;
		
		try {
			is = new FileInputStream(fi);
			os = new FileOutputStream(fo);
			
			int b;
			while ((b = is.read()) != -1) {
			os.write(b);
			}
			
			System.out.println("The content of the file aa.txt is copied to the file bb.txt");
			
			/*int b = is.read();
			while (b != -1) {
				os.write(b);
				b = is.read();
			}*/
			
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (is != null) {
				try {
					is.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
			if (os != null) {
				try {
					os.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}