Send email via WSO2 ESB with several attachments

WSO2 ESB Mail transport allows you to send a email only with 1 attachment. If you want to send number of attachments here's the solution.

Scenario: Here I want to extract some content from the input message and attach to the email as two different attachment.

Solution: You can achieve this requirement using Gmail connector.

Steps: 

1. Add the Gmail connector to the ESB and enable it.
1. You can download the esb connector here https://storepreview.wso2.com/store/assets/esbconnector/a1fba975-89fb-4bb0-a1b9-9f9d061fb31c
2. Add it to the ESB and enable it https://docs.wso2.com/display/ESB481/Managing+Connectors+in+Your+ESB+Instance
3. Gmail connector documentation https://docs.wso2.com/display/ESBCONNECTORS/Gmail+Connector

2. Setup the scenario: split the input message and send it with an email using two different attachments.
1. Input message I used

<email>

       <username>sender@gmail.com</username>

       <password>password</password>

       <subject>This is the subject of the mail</subject>

       <toRecipients>receiver@gmail.com</toRecipients>   

       <textContent>This is the text content of the mail</textContent>      

       <part1>Content of the Part 1</part1>

       <part2>Content of the Part 2</part2>      

</email>

2. proxy configuration

<proxy xmlns="http://ws.apache.org/ns/synapse"

      name="gmailProxy"

      transports="https,http"

      statistics="disable"

      trace="disable"

      startOnLoad="true">

  <target>

     <inSequence>

        <property name="username" expression="//username/text()"/>

        <property name="password" expression="//password/text()"/>

        <property name="subject" expression="//subject/text()"/>

        <property name="toRecipients" expression="//toRecipients/text()"/>

        <property name="textContent" expression="//textContent/text()"/>

        <class name="org.test.mediator.SimpleClassMediator"/>

        <property name="FORCE_SC_ACCEPTED" value="true" scope="axis2"/>

        <gmail.passwordLogin>

           <username>{$ctx:username}</username>

           <password>{$ctx:password}</password>

        </gmail.passwordLogin>

        <log level="custom">

           <property name="login" value="success"/>

        </log>

        <gmail.sendMail>

           <subject>{$ctx:subject}</subject>

           <toRecipients>{$ctx:toRecipients}</toRecipients>

           <textContent>{$ctx:textContent}</textContent>

           <attachmentIDs>part1.txt,part2.txt</attachmentIDs>

        </gmail.sendMail>

     </inSequence>

  </target>

  <description/>

</proxy>

3. Develop a custom class mediator to split the message parts and add it to the synapse MessageContext as attachments. 

          Refer https://docs.wso2.com/display/ESB481/Writing+a+WSO2+ESB+Mediator

          Here is the custom class mediator I wrote for this scenario 

package org.test.mediator;

import org.apache.axiom.om.OMElement;

import org.apache.axiom.om.xpath.AXIOMXPath;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.apache.synapse.MessageContext;

import org.apache.synapse.core.axis2.Axis2MessageContext;

import org.apache.synapse.mediators.AbstractMediator;

import org.jaxen.JaxenException;

import javax.activation.DataHandler;

import javax.mail.util.ByteArrayDataSource;

public class SimpleClassMediator extends AbstractMediator {

  private static final Log log = LogFactory.getLog(SimpleClassMediator.class);

  @Override public boolean mediate(MessageContext messageContext) {

      OMElement bodyContent = messageContext.getEnvelope().getBody().getFirstElement();

      try {

          AXIOMXPath xPathPart1 = new AXIOMXPath("//part1");

          String part1 = ((OMElement) xPathPart1.selectSingleNode(bodyContent)).getText();

          AXIOMXPath xPathPart2 = new AXIOMXPath("//part2");

          String part2 = ((OMElement) xPathPart2.selectSingleNode(bodyContent)).getText();

          org.apache.axis2.context.MessageContext axis2MsgCtx =

              ((Axis2MessageContext) messageContext).getAxis2MessageContext();

          javax.activation.DataHandler handler1 = new DataHandler(new ByteArrayDataSource(part1.getBytes(), "text/plain"));

          axis2MsgCtx.addAttachment("part1.txt", handler1 );

          javax.activation.DataHandler handler2 = new DataHandler(new ByteArrayDataSource(part2.getBytes(), "text/plain"));

          axis2MsgCtx.addAttachment("part2.txt", handler2);

      } catch (JaxenException e) {

          log.error("Error while adding attachments...", e);

      }

      return true;

  }

} 

Now the setup is done, restart the ESB and send the request.

(Versions: ESB 4.8.1, Gmail Connector 1.0.0)

More reading: http://wso2.com/library/1148/