小编Roy*_*Roy的帖子

我一直在学习如何制作Java Spring Web服务,但在尝试发送邮件时遇到了一个问题.

当我尝试通过我的控制器发送代码时,代码工作正常,但我试图将代码放在一个单独的类中,我突然得到一个NullPointerException,即使代码是相同的(据我所知).

这是目前提出问题的功能:

package com.tenshin_arts.inventory.mail;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.mail.MailSender;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;

import com.tenshin_arts.inventory.dao.InventoryItem;
import com.tenshin_arts.inventory.dao.User;
import com.tenshin_arts.inventory.service.InventoryService;

public class InventoryMail {


       @Autowired
       private MailSender mailSender;

    public void stockBelowMinimumUpdate(InventoryItem inventoryItem) {

        String email = "xxxx@gmail.com";
        String text= "";

        text += "Het volgende product is onder het minimum gekomen:\n\n";
        text += "Productnaam: " + inventoryItem.getName();
        text += "\nProductcode: " + inventoryItem.getBarcode();
        text += "\nHuidige Voorraad: " + inventoryItem.getCurrentStock();
        text += "\nMinimum Voorraad: …