SpingMVC中Utils工具类静态方法调用Service层 引言之前在百度、CSDN上查询了各种方法，一直都是空指针异常，原因就是static问题。先上图。之前把service层用@PostConstruct赋值后就直接用静态去获取成Settings就是这里出的问题。解决对于定义的Static变量赋值问题应该把调用的service层以及获取数据全部放在init初始化里。就不会报错。对于方法而言就直接调用就行。下面是代码@Component public class MailConfig { @Autowired private SettingsService settingsService; public static MailConfig mailConfig; private static final String PROPERTIES_DEFAULT = "mailConfig.properties"; public static String host; public static Integer port; public static String userName; public static String passWord; public static String emailForm; public static String timeout; public static String personal; public static Properties properties; @PostConstruct public void init(){ mailConfig = this; mailConfig.settingsService = this.settingsService; try { MailSettings ms = JSON.parseObject(mailConfig.settingsService.getSettings().getMailSettings(), MailSettings.class); host = ms.getMailHost(); port = new Integer(ms.getMailPort()); userName = ms.getMailUsername(); passWord = ms.getMailPassword(); emailForm = ms.getMailUsername(); timeout = ms.getMailTimeout(); personal = ms.getPersonal(); }catch (Exception e) { e.printStackTrace(); } } public static void xx(){ mailConfig.settingsService.xx(); } }