Compare the contents of two Streams to determine if they are equal or not in Java

/*www  . j  a v a  2s .c  om*/
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
public class Main {

  public static boolean contentEquals(InputStream input1, InputStream input2) throws IOException
  {
    if (!(input1 instanceof BufferedInputStream))
    {
      input1 = new BufferedInputStream(input1);
    }
    if (!(input2 instanceof BufferedInputStream))
    {
      input2 = new BufferedInputStream(input2);
    }

    int ch = input1.read();
    while (-1 != ch)
    {
      int ch2 = input2.read();
      if (ch != ch2)
      {
        return false;
      }
      ch = input1.read();
    }

    int ch2 = input2.read();
    return (ch2 == -1);
  }
}