Scheduling with Quartz and Spring

Scheduling with Quartz and Spring

This has been covered in various forms for quite some time but here is my preferred solution to running a job from your app server.  Typical use cases for this are reports, system status checks or cleanup operations.

What is the JavaBean/POJO to be called?

<bean name="systemMonitorBean" class="com.myco.HostPortMonitor">         <property name="serverList" value="${system.monitoring.serverport.locations}"/>         <property name="timeout" value="${system.monitoring.serverport.timeout}"/>         <property name="emailTo" value="${system.monitoring.serverport.emailto}"/>         <property name="emailSender" ref="emailSender"/>

 The properties above are grabbed from a file on the classpath: 

<context:property-placeholder location="classpath*:myapp.properties"/>

I find the best way to call the Java class above is to get Spring to call a method on it:

<bean id="methodInvokingJob" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">         <property name="targetObject" ref="systemMonitorBean"/>         <property name="targetMethod" value="checkSystems"/>     </bean>

Now this effectively is a Quartz "job", ie the pojo and its specified method have become the subject of a Quartz job and can therefore be called by Quartz.  So the rest of the setup is to have a trigger, in this case a simple check every hour (time is defined in milliseconds):

<bean id="serverPortMonitoringTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">         <property name="jobDetail" ref="methodInvokingJob"/>         <property name="startDelay" value="10000"/>         <property name="repeatInterval" value="3600000"/>     </bean>

You could use a CRON trigger as well: http://www.quartz-scheduler.org/docs/tutorials/crontrigger.html

Final step is to have a scheduler running that can call multiple triggers:

<bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">         <property name="triggers">             <list>                 <ref bean="serverPortMonitoringTrigger"/>             </list>         </property>     </bean>

Very easy.

Used in this were some other helper classes.  The Java class being called is just a simple check if a server:port is running and email out:  

public class HostPortMonitor extends BaseSystemMonitor {     private String serverList;     private Integer timeout;     private List<ServerPort> serverPortList = new ArrayList<ServerPort>();     @Override     public void checkSystems() {         if (ObjectUtil.isEmpty(timeout) || timeout < 100) {             timeout = 10000;         }         for (ServerPort serverPort : serverPortList) {             log.info("Checking system up/down for: " + serverPort.getServerName() + ":" + serverPort.getPort());             try {                 if (NetworkUtils.checkServerPort(serverPort.getServerName(), serverPort.getPort(), timeout)) {                     String checkStatus = "OK";                     sendEmail(serverPort, checkStatus);                 } else {                     String checkStatus = "FAILED - No Connect";                     sendEmail(serverPort, checkStatus);                 }             } catch (UtilException e) {                 log.error("Could not check server:port - " + serverPort.getServerName() + ":" + serverPort.getPort(), e);                 String checkStatus = "FAILED - " + e.getMessage();                 sendEmail(serverPort, checkStatus);             }         }     }     private void sendEmail(ServerPort serverPort, String checkStatus) {         StringBuilder body = buildMessageBody(serverPort, checkStatus);         try {             log.info("Sending email for system up/down: " + body);             emailSender.sendGenericEmail(emailTo, "Monitor: " + checkStatus, body.toString());         } catch (MessagingException e) {             log.warn("While emailing system monitor report I received error: " + e.getMessage());         }     }     private StringBuilder buildMessageBody(ServerPort serverPort, String checkStatus) {         StringBuilder body = new StringBuilder();         body.append("System check: ").append(checkStatus).append(TextUtil.getLineSeparator());         body.append("To server:port - ").append(serverPort.getServerName());         body.append("At time: ").append(new Date()).append(TextUtil.getLineSeparator());         body.append(":").append(serverPort.getPort()).append(TextUtil.getLineSeparator());         return body;     }     public Integer getTimeout() {         return timeout;     }     public void setTimeout(Integer timeout) {         this.timeout = timeout;     }     public String getServerList() {         return serverList;     }     public void setServerList(String serverList) {         this.serverList = serverList;         String[] serverPorts = serverList.split(";");         for (String serverPort : serverPorts) {             String[] split = serverPort.split(":", 2);             serverPortList.add(new ServerPort(split[0], split[1]));         }     }     class ServerPort {         String serverName;         Integer port;         ServerPort(String serverName, String portString) {             this.serverName = serverName;             if (ObjectUtil.isEmpty(portString)) {                 this.port = 80;             } else {                 try {                     this.port = Integer.parseInt(portString);                 } catch (NumberFormatException e) {                     this.port = 80;                 }             }         }         public String getServerName() {             return serverName;         }         public void setServerName(String serverName) {             this.serverName = serverName;         }         public Integer getPort() {             return port;         }         public void setPort(Integer port) {             this.port = port;         }     } }

The properties are read from a file included in the classpath using standard Java properties syntax

system.monitoring.serverport.locations=goolge.com:80 system.monitoring.serverport.timeout=3000 # etc...

The basic code for the EmailSender is:

public class EmailSender extends JavaMailSenderImpl {     public void sendGenericEmail(String emailIds, String subject, String body, EmailAttachment... attachments) throws MessagingException {         MimeMessage message = super.createMimeMessage();         // use the true flag to indicate you need a multipart message         MimeMessageHelper helper = new MimeMessageHelper(message, true);         helper.setTo(emailIds);         // use the true flag to indicate the text included is HTML         helper.setSubject(subject);         helper.setText(body, false);         for (EmailAttachment attachment : attachments) {             helper.addAttachment(attachment.getName(), attachment.getBodyAsStream());         }         // let's include the infamous windows Sample file (this time copied to c:/)         /*FileSystemResource res = new FileSystemResource(new File("c:/Sample.jpg"));         helper.addInline("identifier1234", res);*/         send(message);     } }

system.monitoring.serverport.locations=goolge.com:80 system.monitoring.serverport.timeout=3000 # etc...