Spring Boot：将Bean注入到HttpServlet中

Question

我有一个Spring Boot，我已经自动配置了一个Router Bean。 这一切都可以完美运行，但是当我想对这个bean注入到一个特定的Servlet它成为一个问题：

public class MembraneServlet extends HttpServlet { 
    @Autowired 
    private Router router; 

    @Override 
    public void init() throws ServletException { 
     SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this); 
    } 

    @Override 
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 
     new HttpServletHandler(req, resp, router.getTransport()).run(); 
    } 
} 

这应该是要走的路，但

SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this); 

不会自动装配的因为WebapplicationContext始终为空。该应用程序在MVC环境中运行。

Answer 1

假设你的Spring应用上下文被连接到servlet上下文，你可能想将ServletContext传递给SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext

public class MembraneServlet extends HttpServlet { 

    @Autowired 
    private Router router; 

    @Override 
    public void init() throws ServletException { 
     SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this, getServletContext()); 
    } 

    @Override 
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 
     new HttpServletHandler(req, resp, router.getTransport()).run(); 
    } 
} 

Answer 2

注入'Router'作为构造参数怎么样？

所以你要有这样的：

public class MembraneServlet extends HttpServlet { 

    private Router router; 

    public MembraneServlet(Router router){ 
     this.router = router; 
    } 

    @Override 
    public void init() throws ServletException { 
     SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this); 
    } 

    @Override 
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { 
     new HttpServletHandler(req, resp, router.getTransport()).run(); 
    } 
} 

则可以编程方式创建的servlet注册是这样的：

@Bean 
public ServletRegistrationBean membraneServletRegistrationBean(){ 
    return new ServletRegistrationBean(new MembraneServlet(),"/*"); 
}