尝试向 Queue 类添加异常

public class queuefullexception extends exception {
  int size;
  queuefullexception(int s) { size = s; }
  public string tostring() {
    return "\nqueue is full. maximum size is " + size;
  }
}

public class queueemptyexception extends exception {
  public string tostring() {
    return "\nqueue is empty.";
  }
}

class fixedqueue implements icharq {
  private char q[];
  private int putloc, getloc;

  public fixedqueue(int size) {
    q = new char[size];
    putloc = getloc = 0;
  }

  public void put(char ch) throws queuefullexception {
    if (putloc == q.length)
      throw new queuefullexception(q.length);
    q[putloc++] = ch;
  }

  public char get() throws queueemptyexception {
    if (getloc == putloc)
      throw new queueemptyexception();
    return q[getloc++];
  }
}

class qexcdemo {
  public static void main(string args[]) {
    fixedqueue q = new fixedqueue(10);
    char ch;
    int i;
    try {
      for(i=0; i < 11; i++) {
        system.out.print("attempting to store : " + (char) ('a' + i));
        q.put((char) ('a' + i));
        system.out.println(" - ok");
      }
    } catch (queuefullexception exc) {
      system.out.println(exc);
    }

    try {
      for(i=0; i < 11; i++) {
        system.out.print("getting next char: ");
        ch = q.get();
        system.out.println(ch);
      }
    } catch (queueemptyexception exc) {
      system.out.println(exc);
    }
  }
}

public interface ICharQ {
  void put(char ch) throws QueueFullException;
  char get() throws QueueEmptyException;
}