武林外传—武三通的zuul之惑

public class ExampleSurgicalDebugFilter extends ZuulFilter {
     @Override
    String filterType() {
        return "pre"
    }

     @Override
    int filterOrder() {
        return 96
    }

     @Override
    boolean shouldFilter() {
        RequestContext.currentContext.getRequest().getRequestURI().matches("/api/test.*")
    }

     @Override
    Object run() {
         RequestContext.currentContext.routeHost = new URL("http://example.com");
        if (HTTPRequestUtils.getInstance().getQueryParams() == null) {
            RequestContext.getCurrentContext().setRequestQueryParams(new HashMap<String, List<String>>());
        }
        HTTPRequestUtils.getInstance().getQueryParams().put("debugRequest", ["true"])
        RequestContext.currentContext.setDebugRequest(true)
        RequestContext.getCurrentContext().zuulToZuul = true
     }
 }

zuul:
  routes:
    users:
      path: /myusers/**
      url: http://example.com/users_service

zuul:
  routes:
   users:
      path: /myusers/**
      serviceId: users

ribbon:
  eureka:
    enabled: false

users:
  ribbon:
    listOfServers: example.com,google.com

if (!location.startsWith("http:") && !location.startsWith("https:")) {
    if (location.startsWith("forward:")) {
        ctx.set("forward.to", StringUtils.cleanPath(location.substring("forward:".length()) + route.getPath()));
        ctx.setRouteHost((URL)null);
        return null;
    }

    ctx.set("serviceId", location);
    ctx.setRouteHost((URL)null);
    ctx.addOriginResponseHeader("X-Zuul-ServiceId", location);
} else {
    ctx.setRouteHost(this.getUrl(location));
    ctx.addOriginResponseHeader("X-Zuul-Service", location);
}

public class CustomErrorFilter extends ZuulFilter {
@Override
public String filterType() {
    return "error";
}

@Override
public int filterOrder() {
    //需要在默认的 SendErrorFilter 之前
    // Needs to run before SendErrorFilter which has filterOrder   == 0
    return CUSTOM_ERROR_FILTER_ORDER;
}

@Override
public boolean shouldFilter() {
    // only forward to errorPath if it hasn't been forwarded to already
    return RequestContext.getCurrentContext().containsKey("throwable");
}

@Override
public Object run() {
    try {
        RequestContext ctx = RequestContext.getCurrentContext();
        Exception e = (Exception)ctx.get("throwable");

        if (e != null ) {
            // 根据具体的业务逻辑来处理
            ctx.setResponseBody(JSONUtil.toJSONString(serverError(e)));
            // Remove error code to prevent further error handling in follow up filters
            // 删除该异常信息,不然在下一个error过滤器中还会被执行处理
            ctx.remove("throwable");
            ctx.getResponse().setContentType("application/json;charset=UTF-8");
            ctx.setSendZuulResponse(false);
        }
    } catch (Exception ex) {
        logger.error("catch and handle exception in "+", exception: " +
                ex.getMessage(), ex);
    }
    return null;
}
}

try {
    preRoute();
} catch (ZuulException e) {
    error(e);
    postRoute();
    return;
}

try {
    route();
} catch (ZuulException e) {
    error(e);
    postRoute();
    return;
}

try {
    postRoute();
} catch (ZuulException e) {
    error(e);
    return;
}

public class ExamplePostFilter extends ZuulFilter {

    @Override
    public String filterType() {
        return FilterConstants.POST_TYPE;
    }

    @Override
    public int filterOrder() {
        return FilterConstants.SEND_RESPONSE_FILTER_ORDER-1;
    }

    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() {

        RequestContext context = RequestContext.getCurrentContext();
        try {
            //处理过程中异常
        } catch (Exception e) {
          context.setResponseBody(JSONUtil.toJSONString(serverError()));
            context.getResponse().setContentType("application/json;charset=UTF-8");
            context.setSendZuulResponse(false);
        }

        return null;
    }
}