java如何在SpringMVC4中在Servlet中注入依赖关系？

Question

目前，在基于SpringMVC的应用程序中，我也在实现servlet（这是一个HealthCheckservlet）。 我试图使用@Autowire注释在这个servlet中注入一个类的依赖项，但这个类并没有实例化

请考虑下面的代码。

@WebServlet(name = "myServlet", urlPatterns = "/app2")
public class HealthCheckController extends HealthCheckServlet{

/** The Constant serialVersionUID. */

    private static final long serialVersionUID = 1L;

    @Autowire
      private MyService service;

    /**
     * method to check healthiness.
     *
     * @return true, if is healthy
     * @throws HealthCheckException the health check exception
     */
    @Override
    public boolean isHealthy() throws HealthCheckException {
        try {
            service.showDetails("12", false,null);
            System.out.println("True");
            return true;
        } catch (Exception  e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return false;
    }

您能建议我如何提供MyService类的依赖关系吗

提前谢谢

Answer 1

添加注释中提到的“@Controller”，并更新URL映射。还有，什么叫isHealthy（）？尝试在那里添加url映射

@Controller
public class HealthCheckController extends HealthCheckServlet{

private static final long serialVersionUID = 1L;

@Autowire
  private MyService service;

@RequestMapping("/app2/*")
public boolean isHealthy() throws HealthCheckException {
    try {
        service.showDetails("12", false,null);
        System.out.println("True");
        return true;
    } catch (Exception  e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

Answer 2

这不是Spring管理的bean。尝试将@Component添加到类声明中

@Component
@WebServlet(name = "myServlet", urlPatterns = "/app2")
public class HealthCheckController extends HealthCheckServlet{

您还可以尝试将类重构为Spring控制器：

@Controller
@RequestMapping("app2")
public class HealthCheckController extends HealthCheckServlet{

您可以尝试的另一件事是在web中添加servlet。xml而不是使用@WebServlet注释

<servlet>
    <servlet-name>myServlet</servlet-name>
    <servlet-class>mypackage.HealthCheckController</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>myServlet</servlet-name>
    <url-pattern>/app2</url-pattern>
</servlet-mapping>