2. Writing Server-Side Plug-ins: Background

<alert-plugin
         name="alert-email"
         displayName="Alert:Email"
         xmlns="urn:xmlns:rhq-serverplugin.alert"
         xmlns:c="urn:xmlns:rhq-configuration"
         xmlns:serverplugin="urn:xmlns:rhq-serverplugin"
         package="org.rhq.enterprise.server.plugins.alertEmail"
         description="Alert sender plugin that sends alert notifications via email"
         version="1.0"
         >

<serverplugin:plugin-component class="MyLifecycleListener" />

<plugin-class>RolesSender</plugin-class>

<xs:element name="alert-plugin">

<alert-plugin>
Stuff
</alert-plugin>

<xs:attribute name="name">

<alert-plugin name="myAlertPlugin">
Stuff
</alert-plugin>

git clone http://git.fedorahosted.org/git/rhq/rhq.git

<alert-plugin
     name="alert-email"
     displayName="Alert:Email"
     xmlns="urn:xmlns:rhq-serverplugin.alert"
     xmlns:c="urn:xmlns:rhq-configuration"
     xmlns:serverplugin="urn:xmlns:rhq-serverplugin"
     package="org.rhq.enterprise.server.plugins.alertEmail"
     description="Alert sender plugin that sends alert notifications via email"
>

<serverplugin:help>
     Used to send notifications to direct email addresses.
</serverplugin:help>

Figure 3. Alert Help Text

<!-- startup & tear down listener, + scheduled jobs
<serverplugin:plugin-component />
-->

<!-- Global preferences for all email alerts -->

<serverplugin:plugin-configuration>
     <c:simple-property name="mailserver" displayName="Mail server address" type="longString"
          description="Address of the mail server to use (if not the default JBoss ON one )"
          required="false"/>
     <c:simple-property name="senderEmail" displayName="Email of sender" type="string"
          description="Email of the account from which alert emails should come from"
          required="false"/>
     <c:simple-property name="needsLogin" displayName="Needs credentials?"
          description="Mark this field if the server needs credentials to send email and give them below" type="boolean"
          default="false"/>
     <c:simple-property name="user" type="string" required="false"/>
     <c:simple-property name="password" type="password" required="false"/>
</serverplugin:plugin-configuration>

<!-- How does this sender show up in drop downs etc -->

<short-name>Email</short-name>

 <!-- Class that does the actual sending -->

<plugin-class>EmailSender</plugin-class>

 <!-- What can a user configure when defining an alert -->

<alert-configuration>
     <c:simple-property name="emailAddress" displayName="Receiver Email Address(es)" type="longString"
          description="Email addresses (separated by comma) used for notifications."/>
     </alert-configuration>

package org.rhq.enterprise.server.plugins.alertEmail;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.rhq.core.domain.alert.Alert;
import org.rhq.core.domain.alert.notification.SenderResult;
import org.rhq.enterprise.server.plugin.pc.alert.AlertSender;
import org.rhq.enterprise.server.util.LookupUtil;

public class EmailSender extends AlertSender {

    @Override
    public SenderResult send(Alert alert) {
        String emailAddressString = alertParameters.getSimpleValue("emailAddress", null);
        if (emailAddressString == null) {
            return SenderResult.getSimpleFailure("No email address given");
        }

        List<String> emails = AlertSender.unfence(emailAddressString, String.class, ",");
        try {
            Set<String> uniqueEmails = new HashSet<String>(emails);
            Collection<String> badEmails = LookupUtil.getAlertManager()
                .sendAlertNotificationEmails(alert, uniqueEmails);

            List<String> goodEmails = new ArrayList<String>(uniqueEmails);
            goodEmails.removeAll(badEmails);

            SenderResult result = new SenderResult();
            result.setSummary("Target addresses were: " + uniqueEmails);
            if (goodEmails.size() > 0) {
                result.addSuccessMessage("Successfully sent to: " + goodEmails);
            }
            if (badEmails.size() > 0) {
                result.addFailureMessage("Failed to send to: " + badEmails);
            }
            return result;
        } catch (Throwable t) {
            return SenderResult.getSimpleFailure("Error sending email notifications to " + emails + ", cause: "
                + t.getMessage());
        }

    }

    @Override
    public String previewConfiguration() {
        String emailAddressString = alertParameters.getSimpleValue("emailAddress", null);
        if (emailAddressString == null || emailAddressString.trim().length() == 0) {
            return "<empty>";
        }
        return emailAddressString;
    }
}

      catch (Exception e) {
         log.warn("Sending of email failed: " + e);
         return SenderResult.getSimpleFailure("Sending failed :" + e.getMessage());

      }
      return SenderResult.getSimpleSuccess("Send notification to " + txt + ", msg-id: " + status.getId());
   }
}