monitor.java

Java经典例程 从外国一大学计算机教授出版物下载的代码 经典

import java.rmi.*;
import java.awt.*;

public class Monitor extends Frame implements Runnable {

  /* The monitor thread   by L Botha and J M Bishop  Jan 1998
	 * ==================   Java 1.1
	 *
	 * Used by the Announcer Server.
	 * Contains the only active code in this server.
	 */
	 
    TextField message;
    AnnouncerServer server;

    public Monitor(AnnouncerServer server) {
      super("Announcer Monitor");
      this.server = server;
      setSize(425,75);
      message = new TextField("",40);      
      message.setFont(new Font("Helvetica",0,20));
      add(message);
      message.setEditable(false);
      setVisible(true);
    }

    public void run() {
        boolean startdelay;
        while (true) {
            startdelay = true;
            if (server.hasMessage()) {
                String msg = server.getMessage();
                while (msg.length() > 0) {
                    String displaymsg = formatString(msg);
                    message.setText("");
                    message.setText(displaymsg);
                    if (startdelay == true) {
                        try { Thread.sleep(1000); } catch (Exception e) {}
                        startdelay = false;
                    }
                    try { Thread.sleep(200); } catch (Exception e) {}
                    msg = msg.substring(1);
                }
                message.setText("");
                server.removeMessage();
            }
            try { Thread.sleep(5000); } catch (Exception e) {}
            String newmsg = AirportMessageClient.getMessage();
            if (newmsg != null) 
                server.sendMessage(newmsg);
        } 
    }

    public String formatString(String msg) {
        if (msg.length() <= 40) 
            return msg;
        else 
        return msg.substring(0,40);
    }
}