import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

/**
 * Zuul 的服務過濾演示
 * <p>Title: LoginFilter</p>
 * <p>Description: </p>
 *
 * @author Lusifer
 * @version 1.0.0
 * @date 2018/5/29 22:02
 */
@Component
public class LoginFilter extends ZuulFilter {

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

    /**
     * 配置過濾型別，有四種不同生命週期的過濾器型別
     * 1. pre：路由之前
     * 2. routing：路由之時
     * 3. post：路由之後
     * 4. error：傳送錯誤呼叫
     * @return
     */
    @Override
    public String filterType() {
        return "pre";
    }

    /**
     * 配置過濾的順序
     * @return
     */
    @Override
    public int filterOrder() {
        return 0;
    }

    /**
     * 配置是否需要過濾：true/需要，false/不需要
     * @return
     */
    @Override
    public boolean shouldFilter() {
        return true;
    }

    /**
     * 過濾器的具體業務程式碼
     * @return
     * @throws ZuulException
     */
    @Override
    public Object run() throws ZuulException {
        RequestContext context = RequestContext.getCurrentContext();
        HttpServletRequest request = context.getRequest();
        logger.info("{} >>> {}", request.getMethod(), request.getRequestURL().toString());
        String token = request.getParameter("token");
        if (token == null) {
            logger.warn("Token is empty");
            context.setSendZuulResponse(false);
            context.setResponseStatusCode(401);
            try {
                context.getResponse().getWriter().write("Token is empty");
            } catch (IOException e) {
            }
        } else {
            logger.info("OK");
        }
        return null;
    }
}