RabbitMQ訊息佇列+spring監聽mq伺服器多個ip,接收消費mq訊息(二)
前文用了註解方式實現監聽多個ip,本文用消費端的類實現ServletContextListener監聽器來實現專案啟動時開啟監聽多個ip。大致的程式碼雷同。
環境和框架:和註解方式完全一樣。ssm+maven3.3.9+jdk1.7
1 由於是實現監聽器,沒有註解,所以並不需要spring的掃包範圍限制。我特地把這個監聽類放到掃包範圍以外來測試。專案結構如下:
2 pom.xml中引入rabbitmq的依賴
<dependency>
<groupId>org.springframework.amqp</groupId >
<artifactId>spring-rabbit</artifactId>
<version>1.3.5.RELEASE</version>
</dependency>
3.com.zhanglf.RabbitMqListenerIpsByImplementsServletContextListener 實現ServletContextListener監聽類介面。並在public void contextInitialized()方法中引入監聽mq的方法。
package com.zhanglf;
import java.io.IOException;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import com.rabbitmq.client.Address;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import com.rabbitmq.client.ShutdownListener;
import com.rabbitmq.client.ShutdownSignalException;
import com.rabbitmq.client.AMQP.BasicProperties;
import com.zlf.bo.StaffBo;
import com.zlf.service.IStaffService;
public class RabbitMqListenerIpsByImplementsServletContextListener implements ServletContextListener {
private Address[] addre;
private String vhost;
private String user;
private String pwd;
private String queueName;
public RabbitMqListenerIpsByImplementsServletContextListener(){
this.addre = new Address[] { new Address("10.100.82.121", 5672),
new Address("10.100.82.122", 5672),
new Address("10.100.82.123", 5672) };
this.vhost = "gf-iih";
this.user = "admin";
this.pwd = "admin";
this.queueName = "tkq.queue";
}
@Override
public void contextInitialized(ServletContextEvent sce) {
WebApplicationContext applicationContext = WebApplicationContextUtils.getWebApplicationContext(sce.getServletContext());
IStaffService staffService = applicationContext.getBean(IStaffService.class);
RabbitMqListenerIpsByImplementsServletContextListener mqListener = new RabbitMqListenerIpsByImplementsServletContextListener();
mqListener.StartQueueListener(new ShutdownListener() {
@Override
public void shutdownCompleted(ShutdownSignalException arg0) {
System.out.println("Connection Shutdown!");
}
}, staffService);
}
@Override
public void contextDestroyed(ServletContextEvent sce) {
}
private Connection getConnection(ShutdownListener listener) {
ConnectionFactory factory = new ConnectionFactory();
factory.setUsername(user);
factory.setPassword(pwd);
factory.setVirtualHost(vhost);
factory.setAutomaticRecoveryEnabled(true);
Connection conn = null;
try {
conn = factory.newConnection(addre);
conn.addShutdownListener(listener);
} catch (IOException e) {
e.printStackTrace();
}
return conn;
}
public void StartQueueListener(ShutdownListener listener,final IStaffService staffService) {
Connection conn = getConnection(listener);
if (conn == null) {
System.out.println("Failed to Create Connection!");
return;
}
try {
final Channel channel = conn.createChannel();
// 設定ACK為手動模式,不在自動ACK
boolean autoAck = false;
/**channel.basicConsume各個引數的解釋
* String queueName:佇列名
* boolean autoAck: 伺服器是否要手動應答/確認,true-不需要。false-需要。所以這裡我們要在處理完業務邏輯後,消費掉mq後傳送ack。
* String consumerTag:用於建立上下文的客戶端標籤。每個標籤都代表一個獨立的訂閱。同一個channel的不同consumer使用不同的標籤。
* Consumer callback: 消費端介面,實現Consumer的最方便方法是繼承DefualtConsumer,並將其作為引數傳給basicConsumer方法。答
*/
channel.basicConsume(queueName, autoAck, "zhanglfConsumerTag",
new DefaultConsumer(channel) {
@Override
public void handleDelivery(
String consumerTag,
Envelope envelope,
BasicProperties properties,
byte[] body)
throws IOException {
long deliveryTag = envelope.getDeliveryTag();
String out = new String(body, "UTF-8");
StaffBo staffBo = staffService.selectByPrimaryKey("s01");
System.out.println("------------------"+staffBo.getName()+"------------");
if ("業務處理結果".equals("業務處理結果")) {
// 通知mq伺服器移除此條mq。設定ack為每條mq都ack,不是批量ack。
channel.basicAck(deliveryTag, false);
} else {
// 如果業務處理異常,通知伺服器回收此條mq。
channel.basicNack(deliveryTag, false, true);
}
}
});
} catch (IOException e) {
e.printStackTrace();
}
}
}
4.在web.xml中引入這個自定義監聽類。
<!--自定義監聽器 -->
<listener>
<listener-class>com.zhanglf.RabbitMqListenerIpsByImplementsServletContextListener
</listener-class>
</listener>
這樣就完成了程式碼開發,注意點就是要使用WebApplicationContextUtils來獲取WebApplicationContext進而可以例項化別的層的類。這裡必須這樣做因為監聽器發生在spring容器初始化之前。當進來啟動監聽時,要呼叫的staffService.selectByPrimaryKey("s01");
還沒有例項化,就會報空指標。
WebApplicationContextUtils講解
WebApplicationContextUtils是一個抽象類,其提供了一個很便利的方法來獲取spring應用的上下文即WebApplicationContext。其中的靜態方法getWebApplicationContext(ServletContext sc),提供一個ServletContext 型別引數即可。其原理十分簡單,在spring容器初始化的方法org.springframework.web.context.ContextLoader.initWebApplicationContext(ServletContext)
中通過servletContext.setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, this.context)
;已經將WebApplicationContext的例項放入ServletContext 中了。然後在工具類的org.springframework.web.context.support.WebApplicationContextUtils.getWebApplicationContext(ServletContext)
中就可以通過傳入的ServletContext引數獲取到WebApplicationContext例項了。