zuul路由网关

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-zuul</artifactId>
</dependency>

@Component
public class MyFilter extends ZuulFilter {
    @Override
    public String filterType() {
        return FilterConstants.PRE_TYPE;
    }
    @Override
    public int filterOrder() {
        return 0;
    }
    //是否走过滤逻辑
    @Override
    public boolean shouldFilter() {
        return true;
    }
    //判断url中是否包含参数testParam，不包含则拦截请求
    @Override
    public Object run() {
        RequestContext ctx = RequestContext.getCurrentContext();
        HttpServletRequest request = ctx.getRequest();
        String testParam = request.getParameter("testParam");
        if( null == testParam){
            System.out.println("缺失关键参数，驳回请求");
            ctx.setSendZuulResponse(false);//是否把该请求转发给具体服务
            ctx.setResponseStatusCode(401);
            try {
                ctx.getResponse().getWriter().write("qing  jiancha  canshu  shifou  wanzheng");
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }
        return null;
    }
}

@Component
public class MyFallbackProvider implements ZuulFallbackProvider {
    @Override
    public String getRoute() {
        return "sms-module"; //匹配所有，用“*”
    }
    @Override
    public ClientHttpResponse fallbackResponse() {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {return HttpStatus.OK;}
            @Override
            public int getRawStatusCode() throws IOException {return 200;}
            @Override
            public String getStatusText() throws IOException { return "OK";}
            @Override
            public void close() {}
            @Override
            public InputStream getBody() throws IOException {
                return new ByteArrayInputStream("{\"msg\":\"error, 少年，你的程序出异常了，这里是失败回调函数\"}".getBytes());
//                return new ByteArrayInputStream("少年，你的程序出异常了，这里是失败回调函数".getBytes());
            }
            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders headers = new HttpHeaders();
                headers.setContentType(MediaType.APPLICATION_JSON);
                return headers;
            }
        };
    }
}