XXL job realizes the code parsing of email sending warnings (line by line code interpretation)

1 Relevant code location

We downloaded xxl-job Source code , To find the alarm Catalog , The code in this directory is the code related to sending warnings for the whole project ,alarm Chinese translation is a warning ;

There are only alarm There is about using email Send warning code

2 Interface JobAlarm

There are 3 File , The first is this interface , The source code of this interface is ：

Why use interfaces , Because the alarm information is predicted , Not only can we send email, And you can also send qq, WeChat , Text messages and other communications ; So just rewrite a class , Implement this interface , That's all right. , Current xxl-job, This project , Just to support email The alarm , We can expand , It is equivalent to writing an interface , It is highly expandable , Easy to maintain .

3 email Warning

We want to achieve email Warn , So write a class , Just implement the above interface ,xxl-job This project is just Support email, So in the future, we want to realize SMS by ourselves , Just write a class by yourself , Implement this interface , Just rewrite the method inside

Now read xxl-job Source code , also email Code for sending warnings ：

Look at this implementation class What's inside ：

Every line of code in the source code , do Commented , Look directly at the source code below

package com.xxl.job.admin.core.alarm.impl;

import com.xxl.job.admin.core.alarm.JobAlarm;
import com.xxl.job.admin.core.conf.XxlJobAdminConfig;
import com.xxl.job.admin.core.model.XxlJobGroup;
import com.xxl.job.admin.core.model.XxlJobInfo;
import com.xxl.job.admin.core.model.XxlJobLog;
import com.xxl.job.admin.core.util.I18nUtil;
import com.xxl.job.core.biz.model.ReturnT;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.mail.javamail.MimeMessageHelper;
import org.springframework.stereotype.Component;

import javax.mail.internet.MimeMessage;
import java.text.MessageFormat;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

/** * job alarm by email *  Notify by email   The alarm information  * @author xuxueli 2020-01-19 */
@Component
public class EmailJobAlarm implements JobAlarm {
    

//  Define the current   Log object 
    private static Logger logger = LoggerFactory.getLogger(EmailJobAlarm.class);

    /** * fail alarm *  Failure alarm   Logic  *  To begin   Alarm logic  * @param jobLog */
    @Override
    public boolean doAlarm(XxlJobInfo info, XxlJobLog jobLog){
    

//  Define alarm result status 
        boolean alarmResult = true;

        // send monitor email
        if (info!=null && info.getAlarmEmail()!=null && info.getAlarmEmail().trim().length()>0) {
    
            //  If   Task information is not empty , The alarm email is not empty 
            // alarmContent  Alarm content 
            String alarmContent = "Alarm Job LogId=" + jobLog.getId();  //  Log id


            if (jobLog.getTriggerCode() != ReturnT.SUCCESS_CODE) {
    
//  If   The log   Scheduling results   You don't succeed  , Content preservation   Dispatch - journal 
                alarmContent += "<br>TriggerMsg=<br>" + jobLog.getTriggerMsg();
            }



            if (jobLog.getHandleCode()>0 && jobLog.getHandleCode() != ReturnT.SUCCESS_CODE) {
    
//  If   perform - state   Not empty , Content preservation   perform - Log specific result information 
                alarmContent += "<br>HandleCode=" + jobLog.getHandleMsg();
            }



            // email info

//  According to the project  id  Query out   actuator （ project ）
            XxlJobGroup group = XxlJobAdminConfig.getAdminConfig().getXxlJobGroupDao().load(Integer.valueOf(info.getJobGroup()));

//  Warning message   Give a person 
            String personal = I18nUtil.getString("admin_name_full");//  The value is this ：  Distributed task scheduling platform XXL-JOB
//  The alarm information   title 
            String title = I18nUtil.getString("jobconf_monitor"); //  The value is this ： The task scheduling center monitors and alarms 

//  According to the template , Fill in the information 
            String content = MessageFormat.format(loadEmailJobAlarmTemplate(),
                    group!=null?group.getTitle():"null",  //  Project name 
                    info.getId(),   //  Mission id
                    info.getJobDesc(),//  Mission   describe 
                    alarmContent); //  Alarm content 

//  Multiple   Alarm mail 
            Set<String> emailSet = new HashSet<String>(Arrays.asList(info.getAlarmEmail().split(",")));


            for (String email: emailSet) {
    

                //  Traverse multiple alarm messages 
                // make mail
                try {
    

                    //  Create a mail sender   object 
                    MimeMessage mimeMessage = XxlJobAdminConfig.getAdminConfig().getMailSender().createMimeMessage();
                    //  establish   Mail sending thread 
                    MimeMessageHelper helper = new MimeMessageHelper(mimeMessage, true);
//  Get the sender of your own configuration from the configuration file   The mailbox of , Sender's name 
                    helper.setFrom(XxlJobAdminConfig.getAdminConfig().getEmailFrom(), personal);
//  Who to send the mail to 
                    helper.setTo(email);
//  Sent title 
                    helper.setSubject(title);
//  Sent content 
                    helper.setText(content, true);
  //  Send 
                    XxlJobAdminConfig.getAdminConfig().getMailSender().send(mimeMessage);
                } catch (Exception e) {
    
                    logger.error(">>>>>>>>>>> xxl-job, job fail alarm email send error, JobLogId:{}", jobLog.getId(), e);

                    alarmResult = false;
                }

            }
        }


//  Return to the alarm state （ Whether the alarm is successful , Default   yes ）
        return alarmResult;
    }

    /** * load email job alarm template *  Load email job alarm template ,, Front end page template  * @return */
    private static final String loadEmailJobAlarmTemplate(){
    
        String mailBodyTemplate = "<h5>" + I18nUtil.getString("jobconf_monitor_detail") + "：</span>" +
                "<table border=\"1\" cellpadding=\"3\" style=\"border-collapse:collapse; width:80%;\" >\n" +
                " <thead style=\"font-weight: bold;color: #ffffff;background-color: #ff8c00;\" >" +
                " <tr>\n" +
                " <td width=\"20%\" >"+ I18nUtil.getString("jobinfo_field_jobgroup") +"</td>\n" +
                " <td width=\"10%\" >"+ I18nUtil.getString("jobinfo_field_id") +"</td>\n" +
                " <td width=\"20%\" >"+ I18nUtil.getString("jobinfo_field_jobdesc") +"</td>\n" +
                " <td width=\"10%\" >"+ I18nUtil.getString("jobconf_monitor_alarm_title") +"</td>\n" +
                " <td width=\"40%\" >"+ I18nUtil.getString("jobconf_monitor_alarm_content") +"</td>\n" +
                " </tr>\n" +
                " </thead>\n" +
                " <tbody>\n" +
                " <tr>\n" +
                " <td>{0}</td>\n" +
                " <td>{1}</td>\n" +
                " <td>{2}</td>\n" +
                " <td>"+ I18nUtil.getString("jobconf_monitor_alarm_type") +"</td>\n" +
                " <td>{3}</td>\n" +
                " </tr>\n" +
                " </tbody>\n" +
                "</table>";

        return mailBodyTemplate;
    }

}

4 JobAlarmer

This class , Because inheritance ApplicationContextAware, InitializingBean
These two classes , So when the project starts , Just load this class

The function of this class is

 stay JobAlarmer When the container in the class initializes, it starts from spring Get... In context 
JobAlarm Class object list:jobAlarmList,（ Main code ：
applicationContext.getBeansOfType(JobAlarm.class);）
alarm Method jobAlarmList Call overridden doAlarm Method 


( Specific implementation of alarm ), When the alarm needs to be triggered ,
 Just call JobAlarmer Class alarm Method ,
 All alarms can be triggered automatically , because xxl By default, only mailbox alarm ,
 The code in this article only posts the email alarm EmailJobAlarm Class code ,
 The advantage of this method is that when other alarm methods are needed ： Such as SMS alarm ,
 Just add class implementation JobAlarm Interface , Use @Component annotation ,
 Rewrite method doAlarm that will do , It will be in JobAlarm Class alarm Method 
jobAlarmList Trigger the SMS alarm method implemented by calling subclasses ,
 Strong expandability , Easy to maintain .

The core of this class is from spring Get from the manager JobAlarm All implementation classes of the interface , in list Inside , Traverse this list, Realize alarms in various ways ;

There is only one email, because xxl-job The project of this family , Just realize this alarm

package com.xxl.job.admin.core.alarm;

import com.xxl.job.admin.core.model.XxlJobInfo;
import com.xxl.job.admin.core.model.XxlJobLog;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
/** *  Context , When the project is initialized   Load this  */
@Component
public class JobAlarmer implements ApplicationContextAware, InitializingBean {
    

//  Definition   The current class   Log object 
    private static Logger logger = LoggerFactory.getLogger(JobAlarmer.class);

//  Context   Manager 
    private ApplicationContext applicationContext;
//  Send alarm information  list
//  Multiple alarm classes  bean Object's   aggregate 
    private List<JobAlarm> jobAlarmList;


    /** *  Set context  */
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
    
        this.applicationContext = applicationContext;
    }

    /** *  Set context  */
    @Override
    public void afterPropertiesSet() throws Exception {
    
//  from spring Manager   Inside   Get   Alarm class  bean object 
//  Get... By type   Multiple bean object 
        Map<String, JobAlarm> serviceBeanMap = applicationContext.getBeansOfType(JobAlarm.class);
        if (serviceBeanMap != null && serviceBeanMap.size() > 0) {
    
            jobAlarmList = new ArrayList<JobAlarm>(serviceBeanMap.values());
        }
    }

    /** * job alarm * * @param info * @param jobLog * @return */
    public boolean alarm(XxlJobInfo info, XxlJobLog jobLog) {
    

        boolean result = false;

//  If   Multiple alarm classes  bean Object's   aggregate   Not empty 
        if (jobAlarmList!=null && jobAlarmList.size()>0) {
    

// result = true  It means   All of the   Call the police email  issue   It's all done 
            result = true;  // success means all-success

            for (JobAlarm alarm: jobAlarmList) {
    
//  Traverse   every last  email Send class object 

//  every last  email Send class object   Whether the transmission is successful 
                boolean resultItem = false;
                try {
    

//  send out email
                    resultItem = alarm.doAlarm(info, jobLog);
                } catch (Exception e) {
    
                    logger.error(e.getMessage(), e);
                }
                if (!resultItem) {
    
                    result = false;
                }
            }
        }

        return result;
    }

}