SpringMVC自定义注解验证登陆拦截

@Retention：注解的保留位置　　　　　　　　　
@Retention(RetentionPolicy.SOURCE)    //注解仅存在于源码中，在class字节码文件中不包含
@Retention(RetentionPolicy.CLASS)     //默认的保留策略，注解会在class字节码文件中存在，但运行时无法获得，
@Retention(RetentionPolicy.RUNTIME)   //注解会在class字节码文件中存在，在运行时可以通过反射获取到
     　　
@Target:注解的作用目标
@Target(ElementType.TYPE)   //接口、类、枚举、注解
@Target(ElementType.FIELD) //字段、枚举的常量
@Target(ElementType.METHOD) //方法
@Target(ElementType.PARAMETER) //方法参数
@Target(ElementType.CONSTRUCTOR)  //构造函数
@Target(ElementType.LOCAL_VARIABLE)//局部变量
@Target(ElementType.ANNOTATION_TYPE)//注解
@Target(ElementType.PACKAGE) ///包   
      
@Document：说明该注解将被包含在javadoc中
       　     
@Inherited：说明子类可以继承父类中的该注解

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 提供登陆拦截注解，默认全局登陆拦截，如果标记required = false则不拦截
 * @author asus
 * @date 2019/8/6
 */
@Target({ ElementType.METHOD, ElementType.TYPE }) //方法和类
@Retention(RetentionPolicy.RUNTIME) //注解会在class字节码文件中存在，在运行时可以通过反射获取到
public @interface RequireLogin {

    boolean required() default true;
}

/**
 * Created by asus on 2019/8/6.
 */
@Component
public class LoginInterceptor extends BaseInterceptor {

    private static Logger logger = LoggerFactory.getLogger(LoginInterceptor.class);


    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        logger.info("进入登陆拦截器...");

        if(isFilter(request, response, (HandlerMethod) handler)){
            return super.preHandle(request, response, handler);
        }

        try {
            if(isLoginCheck){   //这里进行用户身份信息验证
                ResponseUtils.renderText((HttpServletResponse) response, Response.fail("登陆信息失效，请重新登陆获取", ErrorCode.NEED_LOGIN).toString());
                return false;
            }

        } catch (Exception e) {
            logger.error("处理异常" + e.getMessage(), e);
            ResponseUtils.renderText((HttpServletResponse) response,Response.fail("处理失败", ErrorCode.PROCESS_ERROR).toString());

        }

        return super.preHandle(request, response, handler);
    }





    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

    }
}

import com.yllt.common.annotation.RequireLogin;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Created by asus on 2019/8/6.
 */
public class BaseInterceptor extends HandlerInterceptorAdapter {

    public boolean isFilter(HttpServletRequest request, HttpServletResponse response, HandlerMethod handler) {
        // 判断当前method上是否有标签;
        HandlerMethod hm = (HandlerMethod) handler;
        //类上有该标记
        RequireLogin classAnnotation = hm.getBeanType().getAnnotation(RequireLogin.class);
        //方法上有该标记
        RequireLogin methodAnnotation = hm.getMethod().getAnnotation(RequireLogin.class);

        //方法上的注解优先
        RequireLogin requireLogin = methodAnnotation != null ? methodAnnotation : classAnnotation;

        if (requireLogin != null && !requireLogin.required()) {
            // 如果标记required = false 则放行
            return true;
        }

        return false;
    }
}

@Controller
@RequestMapping("app")
@RequireLogin(required = false)
public class LoginAction extends BaseAction{


	@ResponseBody
	@RequestMapping(value="login")
	public Response<?> login(String userName, String password){
        
        return Response.success("111");
	}

    @RequireLogin
    @RequestMapping("index")
    @ResponseBody
    public Response<?> index(){
	    return Response.success("222");
    }
}