netty发送utf-8编码的信息

/**
     * 
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception { // (1)
        
        //发送告警信息
        List<FaultAlarm> faultsAlarms=ReadWarnInfo.getFaultAlarms();
        StringBuilder sb=new StringBuilder();
        for(FaultAlarm fa : faultsAlarms){
            
            sb.append("<?xml version=\"1.0\" encoding=\"UTF-8\" ?>");
            sb.append("<Tel_Alarm>");
            sb.append("<actionName name=\"createAlarmInfo\">");
            sb.append("<param name=\"systemCode\">2</param>");
            sb.append("<param name=\"stationCode\">4</param>");
            sb.append("<param name=\"deviceSN\"> DEVICE004</param>");
            sb.append("<param name=\"deviceType\">DT1</param>");
            sb.append("<param name=\"deviceName\">qqA</param>");
            sb.append("<param name=\"alarmUnitSN\">002</param>");
            sb.append("<param name=\"alarmUnitType\">13</param>");
            sb.append("<param name=\"alarmUnitName\">qqb</param>");
            sb.append("<param name=\"alarmInfoName\">USER REQ SHUTDOWN</param>");
            sb.append("<param name=\"reason\">测试系统故障</param>");
            sb.append("<param name=\"alarmCode\">1</param>");
            sb.append("<param name=\"happenedTime\">1300938099921</param>");
            sb.append("</actionName>");
            sb.append("</Tel_Alarm>");
            sb.append("</xml>");
            sb.append("\n");
            
            ByteBuf bufwarn = ctx.alloc().buffer(3072);
            byte[]  warnsbytes=sb.toString().getBytes("UTF-8"); //只要这里设置一下就可以了！！！
            bufwarn.writeBytes(warnsbytes);
            ChannelFuture f= ctx.writeAndFlush(bufwarn);
            if(f.isSuccess()){
                System.out.println("告警报文发送成功!");
            }
            
            Thread.sleep(5000);
        }
        
    }