我使用Play Mailer 5.0.0使用Play 2.5.12创建了一个应用程序。调用.send()方法时，我收到NullPointerExeception错误。
我有一个Mail.java类和一个MailController.java控制器。 MailController拨打Mail.java。我根据这个解决方案设置了我的代码：
Play framework Mailer throwing NullPointerException at maile.send() method
这是我的MailController.java：
package controllers;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import javax.inject.Inject;
import controllers.helpers.AccessMiddleware;
import models.Comment;
import models.Intake;
import models.User;
import models.utils.Mail;
import play.Configuration;
import play.i18n.Messages;
import play.libs.mailer.MailerClient;
import play.mvc.Controller;
public class MailController extends Controller{
@Inject
MailerClient mailerClient;
public void notifyTeam(Intake intake, Comment comment, String emailType) throws MalformedURLException {
// Set up globals...
String subject = "";
String message = "";
String commentAuthor = "";
String commentDate = "";
String commentText = "";
String testPrefix = Configuration.root().getString("application.emailsubject.testdisregard");
String emailMode = Configuration.root().getString("application.emailmode");
String emailState = Configuration.root().getString("application.emailstate");
String userkey = AccessMiddleware.getSessionUserKey();
User user = User.findByUserKey(userkey);
String userEmail = user.getEmail();
String projectID = intake.getProjectid();
String projectName = intake.getProjectname();
String intakeKey = intake.getRecordkey();
// Build the Send To email addresses...
List<String> emailArray = new ArrayList<String>();
// Build the URL to send...
String urlString = "https://" + Configuration.root().getString("server.hostname") + "/openintake/"
+ intakeKey;
// Validate the URL, will throw an exception if bad...
URL url = new URL(urlString);
switch (emailType) {
case "New":
// Build the subject...
subject = Messages.get("mail.newintake.subject", projectID);
message = Messages.get("mail.newintake.message", url.toString());
emailArray.add(intake.getBamanageremail());
emailArray.add(intake.getSemanageremail());
emailArray.add(intake.getBaassignedemail());
emailArray.add(intake.getBaassignedemail1());
emailArray.add(intake.getBaassignedemail2());
emailArray.add(intake.getSeassignedemail());
emailArray.add(intake.getSeassignedemail1());
emailArray.add(intake.getSeassignedemail2());
break;
case "Comment":
case "Edited Comment":
// Build the subject...
subject = Messages.get("mail.newcomment.subject", projectID, projectName);
if (emailType.equals("Edited Comment")) {
subject = Messages.get("mail.editcomment.subject", projectID, projectName);
}
// Let's add the comment to the message...
commentAuthor = comment.getAuthor();
commentDate = comment.getDatecreated().toString();
commentText = comment.getComment();
message = Messages.get("mail.newcomment.message", projectID, projectName, commentAuthor, commentDate,
commentText, url.toString());
if (emailType.equals("Edited Comment")) {
message = Messages.get("mail.editcomment.message", projectID, projectName, commentAuthor, commentDate,
commentText, url.toString());
}
emailArray.add(intake.getBamanageremail());
emailArray.add(intake.getSemanageremail());
emailArray.add(intake.getBaassignedemail());
emailArray.add(intake.getBaassignedemail1());
emailArray.add(intake.getBaassignedemail2());
emailArray.add(intake.getSeassignedemail());
emailArray.add(intake.getSeassignedemail1());
emailArray.add(intake.getSeassignedemail2());
break;
case "Assigned":
// Build the subject...
subject = Messages.get("mail.assignedintake.subject", projectID, projectName);
message = Messages.get("mail.assignedintake.message", url.toString());
emailArray.add(intake.getRequesterEmail());
break;
default:
return;
}
// Let's remove the current user from the list so not to send the
// email to them...
emailArray = Application.removeValueFromArray(emailArray, userEmail);
// Let's make sure we have some addresses to send to...
if (Application.isArrayEmpty(emailArray) != true) {
// Are we in test email mode?
if (emailMode.equals("test")) {
subject = testPrefix + " " + subject;
message = testPrefix + "<br><br>" + message;
}
Mail mailer = new Mail(mailerClient);
Mail.Envelop envelop = new Mail.Envelop(subject, message, emailArray);
// Are we sending email?
if (emailState.equals("on")) {
mailer.sendMail(envelop);
}
}
}
}
当我调试时，mailerClient永远不会被实例化 - 它总是为空。
Mail.java来自PlayStartApp（https://github.com/yesnault/PlayStartApp）模板：
package models.utils;
import play.Configuration;
import play.Logger;
import play.libs.mailer.Email;
import play.libs.mailer.MailerClient;
import javax.inject.Inject;
import play.libs.Akka;
import scala.concurrent.duration.Duration;
import scala.concurrent.duration.FiniteDuration;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
/**
* Send a mail with PlayStartApp.
* <p/>
* User: yesnault Date: 24/01/12
*/
public class Mail {
MailerClient mailerClient;
public Mail(MailerClient mailerClient) {
this.mailerClient = mailerClient;
}
/**
* 1 second delay on sending emails
*/
private static final int DELAY = 1;
/**
* Envelop to prepare.
*/
public static class Envelop {
public String subject;
public String message;
public List<String> toEmails;
/**
* Constructor of Envelop.
*
* @param subject
* the subject
* @param message
* a message
* @param toEmails
* list of emails adress
*/
public Envelop(String subject, String message, List<String> toEmails) {
this.subject = subject;
this.message = message;
this.toEmails = toEmails;
}
public Envelop(String subject, String message, String email) {
this.message = message;
this.subject = subject;
this.toEmails = new ArrayList<String>();
this.toEmails.add(email);
}
}
/**
* Send a email, using Akka to offload it to an actor.
*
* @param envelop
* envelop to send
*/
@SuppressWarnings("deprecation")
public void sendMail(Mail.Envelop envelop) {
EnvelopJob envelopJob = new EnvelopJob(envelop, mailerClient);
final FiniteDuration delay = Duration.create(DELAY, TimeUnit.SECONDS);
Akka.system().scheduler().scheduleOnce(delay, envelopJob, Akka.system().dispatcher());
}
static class EnvelopJob implements Runnable {
MailerClient mailerClient;
Mail.Envelop envelop;
@Inject
public EnvelopJob(Mail.Envelop envelop, MailerClient mailerClient) {
this.envelop = envelop;
this.mailerClient = mailerClient;
}
public void run() {
Email email = new Email();
final Configuration root = Configuration.root();
final String mailFrom = root.getString("play.mailer.from");
final String mailSign = root.getString("play.mailer.signature");
// email.setFrom(mailFrom);
email.setFrom("BASE Central <basecentral@state.co.us>");
email.setSubject(envelop.subject);
email.setBodyText(envelop.message + "\n\n " + mailSign);
email.setBodyHtml(envelop.message + "<br><br>--<br>" + mailSign);
for (String toEmail : envelop.toEmails) {
email.addTo(toEmail);
Logger.debug("Mail.sendMail: Mail will be sent to " + toEmail);
}
mailerClient.send(email);
Logger.debug("Mail sent - SMTP:" + root.getString("play.mailer.host") + ":"
+ root.getString("play.mailer.port") + " SSL:" + root.getString("play.mailer.ssl") + " User:"
+ root.getString("play.mailer.user") + " Password:" + root.getString("play.mailer.password")
+ " From:" + root.getString(mailFrom));
}
}
}
根据解决方案，我认为此代码应该有效，但我在mailerClient.send(email);的第108行的Mail.java上收到此错误：
[error] a.d.TaskInvocation - null
java.lang.NullPointerException: null
at models.utils.Mail$EnvelopJob.run(Mail.java:108)
at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:39)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:415)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
我很感激帮助。
答案 0 :(得分：0)
mailerClient从未正确注入，因此始终为null。要解决此问题，请在MailController.java中更改：
@Inject
MailerClient mailerClient;
为：
private final MailerClient mailerClient;
@Inject
public MailController(MailerClient mailerClient) {
this.mailerClient = mailerClient;
}
mailerClient现已注入并正常工作。