a Spring interceptor for Weixin(wechat) oauth2

WxAuthInterceptor.java

package top.sdrkyj.custom.config;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import org.springframework.web.util.UriComponentsBuilder;

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

@Component
public class WxAuthInterceptor extends HandlerInterceptorAdapter {
    public static final String REDIRECT_URL_KEY = "top.sdrkyj.custom.config.WxAuthInterceptor_REDIRECT_URL_KEY";
    public static final String STATE_KEY = "top.sdrkyj.custom.config.WxAuthInterceptor_STATE_KEY";
    public static final String WX_USER_KEY = "top.sdrkyj.custom.config.WxAuthInterceptor_WX_USER_KEY";
    private static final Logger logger = LoggerFactory.getLogger(WxAuthInterceptor.class);

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        logger.info("preHandle entered");
        logger.info("request.getSession().getAttribute(WX_USER_KEY), {}", request.getSession().getAttribute(WX_USER_KEY));
        if (request.getSession().getAttribute(WX_USER_KEY) == null) {
            request.setAttribute("redirect", UriComponentsBuilder.fromHttpUrl(String.valueOf(request.getRequestURL())).query(request.getQueryString()).build().toUriString());
            request.getRequestDispatcher("/wx-authorize").forward(request, response);
            return false;
        }
        return true;
    }
}