如何为Spring RESTful Web服务创建Spring Interceptor

Question

我有一些没有web.xml的Spring RESTful(RestControllers)Web服务,我使用Spring启动来启动服务.

我想为Web服务添加授权层,并希望在实际调用Web服务本身之前将所有http请求路由到一个前端控制器.(我有一个代码来模拟autherisation层的会话行为,根据我从客户端发送的每个httpRequest生成的密钥来验证用户).

是否有任何标准Spring解决方案将所有请求路由到过滤器/前端控制器？

提前谢谢,Praneeth

编辑:添加我的代码

控制器:`

@RestController
public class UserService {
    UserDAO userDAO = new UserDAO();

    @RequestMapping(value="/login", method = RequestMethod.POST)
    @LoginRequired
    public String login(@RequestParam(value="user_name") String userName, @RequestParam(value="password") String password, HttpServletRequest request){
        return userDAO.login(userName, password);
    }
}`

拦截器:

`

public class AuthenticationInterceptor implements HandlerInterceptor  {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
        throws Exception {
        System.out.println("In Interceptor");
        //return super.preHandle(request, response, handler);
        return true;
    }
    @Override
    public void postHandle( HttpServletRequest request, HttpServletResponse response,
            Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("---method executed---");
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response,
            Object handler, Exception ex) throws Exception {
        System.out.println("---Request Completed---");
    }
}

`

接口.`

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface LoginRequired {
}

`

Answer 1

可以采取以下步骤来实现Spring的拦截器:

• 实现一个扩展HandlerInterceptorAdapter类的拦截器类.以下是代码的外观:

  public class LoginInterceptor extends HandlerInterceptorAdapter {
  
      @Override
      public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception exception)
      throws Exception {
      // TODO Auto-generated method stub
  
      }
  
      @Override
      public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)
      throws Exception {
      // TODO Auto-generated method stub
  
      }
  
      @Override
      public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
  
          HandlerMethod handlerMethod = (HandlerMethod) handler;
  
          String emailAddress = request.getParameter("emailaddress");
          String password = request.getParameter("password");
  
          if(StringUtils.isEmpty(emailAddress) || StringUtils.containsWhitespace(emailAddress) ||
          StringUtils.isEmpty(password) || StringUtils.containsWhitespace(password)) {
              throw new Exception("Invalid User Id or Password. Please try again.");
          }
  
          return true;
      }
  
  
  }
  

• 实现AppConfig类或在现有Configuration类之一中添加addInterceptors.请注意使用LoginInterceptor实例指定的路径模式

  @Configuration  
  public class AppConfig extends WebMvcConfigurerAdapter  {  
  
      @Override
      public void addInterceptors(InterceptorRegistry registry) {
         registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/account/login");
      }
  } 
  

• 实现控制器方法如下:

  @Controller
  @RequestMapping("/account/login")
  public class LoginController {
  
      @RequestMapping(method = RequestMethod.GET)
      public String login() {
          return "login";
      }
  }
  

Answer 2

这里是拦截器的一个例子:

public class AuthenticationInterceptor implements HandlerInterceptor  {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
        throws Exception {
         HandlerMethod handlerMethod = (HandlerMethod) handler;
        LoginRequired loginRequired = handlerMethod.getMethod().getAnnotation(LoginRequired.class);
        if (loginRequired == null) {
            return true;
        }

        String token = httpServletRequest.getParameter("token");

        if (StringUtils.isBlank(token)) {
            throw new MissingParameterException();
        }

        authenticationService.checkToken(token);

        return super.preHandle(httpServletRequest, httpServletResponse, handler);
    }
    @Override
    public void postHandle( HttpServletRequest request, HttpServletResponse response,
            Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("---method executed---");
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response,
            Object handler, Exception ex) throws Exception {
        System.out.println("---Request Completed---");
    }

我们可以创建一个注释:

 @Target({ElementType.METHOD, ElementType.TYPE})
        @Retention(RetentionPolicy.RUNTIME)
        public @interface LoginRequired {
        }

然后在控制器上,我们有这个注释:

@RequestMapping(value = "/protected/controller")
@LoginRequired
public ResponseEntity<BaseResponse> controller() {
   ...
}

这只是一个模板/示例,可以为您提供一个想法.我希望这能帮到您.