Customizing a Workflow Extension

package org.wso2.sample.workflow;

import java.util.List;
import java.util.Properties;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import org.wso2.carbon.apimgt.api.APIManagementException;
import org.wso2.carbon.apimgt.impl.APIConstants;
import org.wso2.carbon.apimgt.impl.dao.ApiMgtDAO;
import org.wso2.carbon.apimgt.impl.dto.SubscriptionWorkflowDTO;
import org.wso2.carbon.apimgt.impl.dto.WorkflowDTO;
import org.wso2.carbon.apimgt.impl.workflow.WorkflowConstants;
import org.wso2.carbon.apimgt.impl.workflow.WorkflowException;
import org.wso2.carbon.apimgt.impl.workflow.WorkflowExecutor;
import org.wso2.carbon.apimgt.impl.workflow.WorkflowStatus;

public class SubsCreationEmailSender extends WorkflowExecutor {
    private String adminEmail;
    private String emailAddress;
    private String emailPassword;

    @Override
    public List<WorkflowDTO> getWorkflowDetails(String arg0)
            throws WorkflowException {
        return null;
    }

    @Override
    public String getWorkflowType() {
        return WorkflowConstants.WF_TYPE_AM_SUBSCRIPTION_CREATION;
    }
    
    @Override
    public void execute(WorkflowDTO workflowDTO) throws WorkflowException{
        SubscriptionWorkflowDTO subsCreationWFDTO = (SubscriptionWorkflowDTO)workflowDTO;
        
        Properties props = new Properties();
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.port", "587");
        
        Session session = Session.getInstance(props,
                new javax.mail.Authenticator() {
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(emailAddress,
                                emailPassword);
                    }
                });
        
        try {
             
            Message message = new MimeMessage(session);
            message.setFrom(new InternetAddress(emailAddress));
            message.setRecipients(Message.RecipientType.TO,
                InternetAddress.parse(adminEmail));
            message.setSubject("Subscription Creation");
            message.setText("Subscription created for API " + subsCreationWFDTO.getApiName() + 
                            " using Application " + subsCreationWFDTO.getApplicationName() + 
                            " by user " + subsCreationWFDTO.getSubscriber());
 
            Transport.send(message);
            System.out.println("Sent email to notify subscription creation");         
            //Call the execute method of the parent class. This will create a reference for the
            //workflow execution in the database.
            super.execute(workflowDTO);
            //Set the workflow Status to APPROVED and Immediately complete the workflow since we 
            //are not waiting for an external party to complete this.
            workflowDTO.setStatus(WorkflowStatus.APPROVED);
            complete(workflowDTO);
 
        } catch (MessagingException e) {
            e.printStackTrace();
            throw new WorkflowException(e.getMessage());
        } catch (Exception e){
            e.printStackTrace();
            throw new WorkflowException(e.getMessage());
        }
    } 
    
    @Override
    public void complete(WorkflowDTO workflowDTO) throws WorkflowException{
        workflowDTO.setUpdatedTime(System.currentTimeMillis());
        super.complete(workflowDTO);
        ApiMgtDAO apiMgtDAO = new ApiMgtDAO();
        try {
            apiMgtDAO.updateSubscriptionStatus(
                    Integer.parseInt(workflowDTO.getWorkflowReference()),
                    APIConstants.SubscriptionStatus.UNBLOCKED);
        } catch (APIManagementException e) {
            throw new WorkflowException(
                    "Could not complete subscription creation workflow", e);
        }
    }
    public String getAdminEmail() {
        return adminEmail;
    }
    public void setAdminEmail(String adminEmail) {
        this.adminEmail = adminEmail;
    }
    public String getEmailAddress() {
        return emailAddress;
    }
    public void setEmailAddress(String emailAddress) {
        this.emailAddress = emailAddress;
    }
    public String getEmailPassword() {
        return emailPassword;
    }
    public void setEmailPassword(String emailPassword) {
        this.emailPassword = emailPassword;
    }
}