Spring定时任务使用及如何使用邮件监控服务器

Spring相关的依赖导入进去，即可使用spring的定时任务！

<!-- spring核心包 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>4.3.13.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>4.3.13.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>4.3.13.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>4.3.13.RELEASE</version>
    </dependency>

定时任务是开发中常用的，比如订单查询，一位客人订购的某个东西，但是尚未支付，超过订单时效期自动失效，那么又是怎么样知道订单的时效性过呢?定时任务，可以每分钟或者每秒钟进行查询。

定时任务的应用是非常广的，下面应用下监控服务器，虽然说现在开源监控软件挺多的，什么zabbix,nagios或者其他等等。下面我将使用代码监控服务器:

首先准备邮件的依赖:

<!-- 发邮件 -->
    <dependency>
      <groupId>com.sun.mail</groupId>
      <artifactId>javax.mail</artifactId>
      <version>1.5.2</version>
      <scope>provided</scope>
    </dependency>

邮件工具类:

import java.util.Properties;
import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMessage.RecipientType;

public class MailUtils {

  public static void sendMail(String email, String emailMsg)
      throws AddressException, MessagingException {
    // 1.创建一个程序与邮件服务器会话对象 Session

    Properties props = new Properties();
    props.setProperty("mail.transport.protocol", "SMTP");
    props.setProperty("mail.host", "smtp.163.com");
    props.setProperty("mail.smtp.auth", "true");// 指定验证为true

    // 创建验证器
    Authenticator auth = new Authenticator() {
      public PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication("123@163.com", "123");
      }
    };

    Session session = Session.getInstance(props, auth);

    // 2.创建一个Message，它相当于是邮件内容
    Message message = new MimeMessage(session);

    message.setFrom(new InternetAddress("123@163.com")); // 设置发送者

    message.setRecipient(RecipientType.TO, new InternetAddress(email)); // 设置发送方式与接收者

    message.setSubject("邮件告警");

    message.setContent(emailMsg, "text/html;charset=utf-8");

    // 3.创建 Transport用于将邮件发送

    Transport.send(message);

  }

}

监控服务器类:

package cn.pms.monitor; 

import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

import javax.mail.MessagingException;
import javax.mail.internet.AddressException;

import cn.pms.util.MailUtils; 

public class MonitorUrl { 

  public static void testUrlWithTimeOut2016(String urlString,int timeOutMillSeconds){
    long lo = System.currentTimeMillis();
    URL url;
    try {
       url = new URL(urlString);
       URLConnection co = url.openConnection();
       co.setConnectTimeout(timeOutMillSeconds);
       co.connect();
       System.out.println("连接可用");
    } catch (Exception e1) {
       System.out.println("连接打不开!");
       url = null;
       emailMonitor2016();
    }
    System.out.println(System.currentTimeMillis()-lo);
  } 

  public static void testUrlWithTimeOut2018(String urlString,int timeOutMillSeconds){
    long lo = System.currentTimeMillis();
    URL url;
    try {
       url = new URL(urlString);
       URLConnection co = url.openConnection();
       co.setConnectTimeout(timeOutMillSeconds);
       co.connect();
       System.out.println("连接可用");
    } catch (Exception e1) {
       System.out.println("连接打不开!");
       url = null;
       emailMonitor2018();
    }
    System.out.println(System.currentTimeMillis()-lo);
  } 

  public static void testUrlWithTimeOut1818(String urlString,int timeOutMillSeconds){
    long lo = System.currentTimeMillis();
    URL url;
    try {
       url = new URL(urlString);
       URLConnection co = url.openConnection();
       co.setConnectTimeout(timeOutMillSeconds);
       co.connect();
       System.out.println("连接可用");
    } catch (Exception e1) {
       System.out.println("连接打不开!");
       url = null;
       emailMonitor1818();;
    }
    System.out.println(System.currentTimeMillis()-lo);
  } 

  public static void testUrlWithTimeOut1616(String urlString,int timeOutMillSeconds){
    long lo = System.currentTimeMillis();
    URL url;
    try {
       url = new URL(urlString);
       URLConnection co = url.openConnection();
       co.setConnectTimeout(timeOutMillSeconds);
       co.connect();
       System.out.println("连接可用");
    } catch (Exception e1) {
       System.out.println("连接打不开!");
       url = null;
       emailMonitor1616();
    }
    System.out.println(System.currentTimeMillis()-lo);
  } 

  public static void emailMonitor2016() {
    try {
      MailUtils.sendMail("123@qq.com", "tomcat服务器端口为2016宕机了");
    } catch (AddressException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (MessagingException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }

  public static void emailMonitor2018() {
    try {
      MailUtils.sendMail("123@qq.com", "tomcat服务器端口为2018宕机了");
    } catch (AddressException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (MessagingException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }

  public static void emailMonitor1818() {
    try {
      MailUtils.sendMail("1236@qq.com", "tomcat服务器端口为1818宕机了");
    } catch (AddressException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (MessagingException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }

  public static void emailMonitor1616() {
    try {
      MailUtils.sendMail("123@qq.com", "tomcat服务器端口为1616宕机了");
    } catch (AddressException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (MessagingException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }
}

具体定时任务类:

@Component
public class QuartzJob {

private static Logger logger = Logger.getLogger(QuartzJob.class);

  @Scheduled(cron = "0 0/1 * * * ? ")
  public void test() {
    MonitorUrl.testUrlWithTimeOut2018("http://www.yc520.com:2018/", 2000);

    MonitorUrl.testUrlWithTimeOut1616("http://www.yc520.com:1616/", 2000);
    logger.info("每分钟执行" + System.currentTimeMillis());
  }

  @Scheduled(cron = "0 10 0 * * ?")
  public void monitorServerTest() {

    System.out.println("每10分钟监控一次2018服务器和1616服务器");
    MonitorUrl.testUrlWithTimeOut2018("http://www.yc520.com:2018/", 2000);
    MonitorUrl.testUrlWithTimeOut1616("http://www.yc520.com:1616/", 2000);
  }

  @Scheduled(cron="0 30 0 * * ?")
  public void monitorServer() {
    System.out.println("每30分钟监控一次1818测试服务器");
    MonitorUrl.testUrlWithTimeOut1818("http://www.yc520:1818/", 2000);
  }

}

由此就可以达到监控服务器的目的，当然这只是小试牛刀，而且也不够全面，当然也存在问题，如果是每分钟定时任务检测，突然一台服务器挂了，那么将会源源不断的发送邮件，163邮件是有限的，而且频繁的可能会被当成垃圾邮件，我只需要知道一条信息，某某服务器宕机了，一遍就可以，最后给我发三十遍，如此的话，大量的无效邮件很浪费资源，而且浪费时间。

所以说，本文只是一个服务器监控小示例，实际开发中，切勿直接拿来用，最好要有相关的判断和逻辑。这样才能比较高效，达到预期期望。

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