package mis.config;

import mis.interceptor.SpringMVCInterceptor;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration
public class WebAppConfig extends WebMvcConfigurerAdapter {
    /**
     * 配置攔截器
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new SpringMVCInterceptor()).addPathPatterns("/**");
    }
}		
		

package mis.interceptor;

import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

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

public class SpringMVCInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object o) throws Exception {

        if(request.getServletPath().startsWith("/index") || request.getServletPath().startsWith("/login")) {
            return true;
        }

        String username = (String)request.getSession().getAttribute("userName");
        if (StringUtils.isEmpty(username)){
            response.sendRedirect(request.getContextPath() + "/index");
            return false;
        }
        return true;
    }

    @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 {

    }
}