Android Looper和Handler分析(10)

        if (mQueue != null) { 
            synchronized (mQueue) { 
                Message msg = mQueue.mMessages; 
                int n = 0; 
                while (msg != null) { 
                    pw.println(prefix + "  Message " + n + ": " + msg); 
                    n++; 
                    msg = msg.next; 
                } 
                pw.println(prefix + "(Total messages: " + n + ")"); 
            } 
        } 
    } 
 
    public String toString() { 
        return "Looper{" 
            + Integer.toHexString(System.identityHashCode(this)) 
            + "}"; 
    } 
 
    static class HandlerException extends Exception { 
 
        HandlerException(Message message, Throwable cause) { 
            super(createMessage(cause), cause); 
        } 
 
        static String createMessage(Throwable cause) { 
            String causeMsg = cause.getMessage(); 
            if (causeMsg == null) { 
                causeMsg = cause.toString(); 
            } 
            return causeMsg; 
        } 
    } 
}