PHP AMQP的问题：报错

$q->get(AMQP_AUTOACK); 请教关于这个的问题 如果我是这么写 $q->get(); 队列中的数据如何清楚 ######<?php

//设置你的连接
$conn_args = array('host' => 'localhost', 'port' => '5672', 'login' => 'guest', 'password' => 'guest');
$conn = new AMQPConnection($conn_args);
if ($conn->connect()) {
    echo "Established a connection to the broker \n";
}
else {
    echo "Cannot connect to the broker \n ";
}
//你的消息
$message = json_encode(array('Hello World!','php','c++'));
//创建channel
$channel = new AMQPChannel($conn);
//创建exchange
$ex = new AMQPExchange($channel);
$ex->setName('exchange');//创建名字
$ex->setType(AMQP_EX_TYPE_DIRECT);
$ex->setFlags(AMQP_DURABLE | AMQP_AUTODELETE);
echo "exchange status:".$ex->declare();
echo "\n";
//创建队列
$q = new AMQPQueue($channel);
//设置队列名字 如果不存在则添加
$q->setName('queue');
$q->setFlags(AMQP_DURABLE | AMQP_AUTODELETE);
echo "queue status: ".$q->declare();
echo "\n";
echo 'queue bind: '.$q->bind('exchange','route.key');//将你的队列绑定到routingKey
echo "\n";

$channel->startTransaction();
echo "send: ".$ex->publish($message, 'route.key'); //将你的消息通过制定routingKey发送
$channel->commitTransaction();
$conn->disconnect();

?>######

$conn_args = array('host' => '192.168.4.1', 'port' => '5672', 'login' => 'test', 'password' => 'test' ,'vhost'=>'localhost'); 
$cnn = new AMQPConnection($conn_args);
$cnn->connect();

$ch = new AMQPChannel($cnn);

// Declare a new exchange
$ex = new AMQPExchange($ch);
$ex->setName('exchange1');
$ex->setType(AMQP_EX_TYPE_FANOUT);
$ex->declare();

// Create a new queue
$q = new AMQPQueue($ch);
$q->setName('queue1' . time());
$q->declare();

// Bind it on the exchange to routing.key
$q->bind($ex->getName(), 'routing.*');
// Publish a message to the exchange with a routing key
$ex->publish('message', 'routing.1');
$ex->publish('message2', 'routing.2');
$ex->publish('message3', 'routing.3');


for ($i = 0; $i < 3; $i++) {
// Read from the queue
$msg = $q->get(AMQP_AUTOACK);
    echo $msg->getBody() . "\n";
}

$ex->delete();