/**均已编译通过，有何建议，请多多指教。
?*/
import java.net.*;
import java.applet.*;
//import corejava.*;
public class MailboxTest
{? public static void main(String[] args)
?? {? Mailbox mbox = new Mailbox();
????? while (true)
????? {? System.out.println(mbox.status());
???????? String cmd =Mailbox.readLine
?????????????? ("play, text, voice, quit ");
???????? if (cmd.equals("play"))
???????? {? Message m = mbox.remove();
??????????? if (m != null)
??????????? {? System.out.println("From: " + m.getSender());
?????????????? m.play();
??????????? }
???????? }
???????? else if (cmd.equals("text"))
???????? {? String from = Mailbox.readLine("Your name: ");
??????????? boolean more = true;
??????????? String msg = "";
??????????? System.out.println
?????????????? ("Enter message, 'exit' when done");
????????????
??????????? while (more)
??????????? {? String line = Mailbox.readLine();
?????????????? if (line.equals("exit"))
????????????????? more = false;
?????????????? else msg = msg + line + "\n";
??????????? }
??????????? mbox.insert(new TextMessage(from, msg));
???????? }
???????? else if (cmd.equals("voice"))
???????? {? String from = Mailbox.readLine("Your name: ");
??????????? String msg
?????????????? = Mailbox.readLine("Audio file name: ");????????
??????????? mbox.insert(new VoiceMessage(from, msg));
???????? }
???????? else if (cmd.equals("quit"))
??????????? System.exit(0);
????? }???????????
?? }
}
??????????????
abstract class Message
{? public Message(String from) { sender = from; }
?? public abstract void play();
?? public String getSender() { return sender; }
??
?? private String sender;
}
class TextMessage extends Message
{? public TextMessage(String from, String t)
?? { super(from); text = t; }
?? public void play() { System.out.println(text); }
??
?? private String text;
}
class VoiceMessage extends Message
{? public VoiceMessage(String from, String f)
?? { super(from); filename = f; }
??
?? public void play()
?? {? try
????? {? URL u = new URL("file", "localhost", filename);
???????? AudioClip clip = Applet.newAudioClip(u);
???????? clip.play();
????? }
????? catch(Exception e)
????? {
???????? System.out.println("Can't open " + filename);
????? }
?? }??
?? private String filename;
}
class Mailbox
{? public Message remove()
?? {? if (nmsg == 0) return null;
????? Message r = messages[out];
????? nmsg--;
????? out = (out + 1) % MAXMSG;
????? return r;
?? }
??
?? public void insert(Message m)
?? {? if (nmsg == MAXMSG) return;
????? messages[in] = m;
????? nmsg++;
????? in = (in + 1) % MAXMSG;
?? }
??
?? public String status()
?? {? if (nmsg == 0) return "Mailbox empty";
????? else if (nmsg == 1) return "1 message";
????? else if (nmsg
????? else return "Mailbox full";
?? }
??
?? private static final int MAXMSG = 10;
?? private int in = 0;
?? private int out = 0;
?? private int nmsg = 0;
?? private Message[] messages = new Message[MAXMSG];
?? public static int readInt(String prompt)
?? {? while(true)
????? {? printPrompt(prompt);
???????? try
???????? {? return Integer.valueOf
?????????????? (readLine().trim()).intValue();
???????? } catch(NumberFormatException e)
???????? {? System.out.println
?????????????? ("Not an integer. Please try again!");
???????? }
????? }
?? }
?? public static String readLine(String prompt)
?? {? printPrompt(prompt);
????? return readLine();
?? }
?? public static String readLine()
?? {? int ch;
????? String r = "";
????? boolean done = false;
????? while (!done)
????? {? try
???????? {? ch = System.in.read();
??????????? if (ch
?????????????? done = true;
??????????? else if ((char)ch != '\r') // weird--it used to do \r\n translation
?????????????? r = r + (char) ch;
???????? }
???????? catch(java.io.IOException e)
???????? {? done = true;
???????? }
????? }
????? return r;
?? }
?? public static void printPrompt(String prompt)
?? {? System.out.print(prompt + " ");
????? System.out.flush();
?? }
}
