springcloud初学资料

package com.huawei.zuul.filter; import java.io.IOException; import javax.servlet.http.HttpServletRequest; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.cloud.netflix.zuul.filters.support.FilterConstants; import org.springframework.stereotype.Component; import com.netflix.zuul.ZuulFilter; import com.netflix.zuul.context.RequestContext; import com.netflix.zuul.exception.ZuulException; // 网关过滤器 //检测请求参数中是否传了token这个参数，若没传则请求不被路由到具体的服务实例，直接返回响应，状态码为401 @Component public class MyZuulFilter extends ZuulFilter{ private static Logger log = LoggerFactory.getLogger(MyZuulFilter.class); //过滤的具体逻辑 @Override public Object run() throws ZuulException { RequestContext ctx = RequestContext.getCurrentContext(); HttpServletRequest request = ctx.getRequest(); Object accessToken = request.getParameter("token"); if(accessToken == null){ log.warn("token is empty!"); ctx.setSendZuulResponse(false); ctx.setResponseStatusCode(401); try { ctx.getResponse().getWriter().write("token is empty!"); } catch (IOException e) { return null; } } log.info("ok"); return null; } //表示该过滤器是否过滤逻辑，若为true则执行run()方法，若为false则不执行run()方法 @Override public boolean shouldFilter() { return true; } //过滤顺序，值越小越早执行该过滤器 @Override public int filterOrder() { return 0; } /* Zuul过滤器类型共四种：pre,post,routing,error * pre:在请求路由到具体服务之前执行，这种类型的过滤器可以用作安全验证，比如身份验证、参数验证等 * routing:用于将请求路由到具体的微服务实例 * post:请求已经被路由到微服务之后执行，用作收集统计信息、指标，以及将响应传输到客户端 * error:在其他过滤器发生错误时执行 * */ @Override public String filterType() { return FilterConstants.PRE_TYPE; } }