Differenza tra CharArrayWriter e BufferedImputStream

[giannino1995]

Sto cercando di capire le differenze tra BufferedRead e BufferedImputStream ma ho qualche dubbio:

Mi sapreste spiegare le differenze tra questi due codici del mio libro?

package esempi_dal_libro;
import java.io.*;
public class Esempio {
    public static void main(String args[]) throws IOException { 
        String s = "~This is a © copyright symbol " + 
          "but this is &copy not.\n"; 
        char buf[] = new char[s.length()]; 
        s.getChars(0, s.length(), buf, 0); 
        CharArrayReader in = new CharArrayReader(buf); 
        int c; 
        boolean marked = false; 
        try ( BufferedReader f = new BufferedReader(in) ) 
        { 
          while ((c = f.read()) != -1) { 
            switch(c) { 
            case '&': 
              if (!marked) { 
                f.mark(32); 
                marked = true; 
              } else { 
                marked = false; 
              } 
              break; 
            case ';': 
              if (marked) { 
                marked = false; 
                System.out.print("(c)"); 
              } else 
                System.out.print((char) c); 
              break; 
            case ' ': 
              if (marked) { 
                marked = false; 
                f.reset(); 
                System.out.print("&"); 
              } else 
                System.out.print((char) c); 
              break; 
            default: 
              if (!marked) 
                System.out.print((char) c); 
              break; 
            } 
          } 
        } catch(IOException e) { 
          System.out.println("I/O Error: " + e); 
        } 
      }     
} 

package esempi_dal_libro;
import java.io.*;
public class Esempio {
    public static void main(String args[]) { 
        String s = "~This is a © copyright symbol " + 
          "but this is &copy not.\n"; 
        byte buf[] = s.getBytes(); 
     
        ByteArrayInputStream in = new ByteArrayInputStream(buf); 
        int c; 
        boolean marked = false; 
     
        // Use try-with-resources to manage the file. 
        try ( BufferedInputStream f = new BufferedInputStream(in) ) 
        { 
          while ((c = f.read()) != -1) { 
            switch(c) { 
            case '&': 
              if (!marked) { 
                f.mark(32); 
                marked = true; 
              } else { 
                marked = false; 
              } 
              break; 
            case ';': 
              if (marked) { 
                marked = false; 
                System.out.print("(c)"); 
              } else 
                System.out.print((char) c); 
              break; 
            case ' ': 
              if (marked) { 
                marked = false; 
                f.reset(); 
                System.out.print("&"); 
              } else 
                System.out.print((char) c); 
              break; 
            default: 
              if (!marked) 
                System.out.print((char) c); 
              break; 
            } 
          } 
        } catch(IOException e) { 
          System.out.println("I/O Error: " + e); 
        } 
      } 
}