Three ways Java reads the contents of a file code snippets share the of Java file operation

try {
           //Methods a
           BufferedReader br = new BufferedReader(new FileReader(new File(
                   "D:\1.xls")));
           // StringBuilder bd = new StringBuilder();
           StringBuffer bd = new StringBuffer();
           while (true) {
               String str = br.readLine();
               if (str == null) {
                   break;
               }
               System.out.println(str);
               bd.append(str);
           }
           br.close();
           // System.out.println(bd.toString());
           //Method 2
           InputStream is = new FileInputStream(new File("d:\1.xls"));
           byte b[] = new byte[Integer.parseInt(new File("d:\1.xls").length()
                   + "")];
           is.read(b);
           System.out.write(b);
           System.out.println();
           is.close();
           //Methods three
           Reader r = new FileReader(new File("d:\1.xls"));
           char c[] = new char[(int) new File("d:\1.xls").length()];
           r.read(c);
           String str = new String(c);
           System.out.print(str);
           r.close();
       } catch (RuntimeException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       } catch (FileNotFoundException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       } catch (IOException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }