SpringCloud系列第07节之服务网关Zuul

package com.xuanyuv.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

//创建服务注册中心
@EnableEurekaServer
@SpringBootApplication
public class ServiceDiscoveryBootStrap {
    public static void main(String[] args) {
        SpringApplication.run(ServiceDiscoveryBootStrap.class, args);
    }
}

package com.xuanyuv.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

/**
 * 通过 @EnableEurekaClient 注解，为服务提供方赋予注册和发现服务的能力
 * --------------------------------------------------------------------------------------------
 * 也可以使用org.springframework.cloud.client.discovery.@EnableDiscoveryClient注解
 * 详见以下两篇文章的介绍
 * http://cloud.spring.io/spring-cloud-static/Camden.SR3/#_registering_with_eureka
 * https://spring.io/blog/2015/01/20/microservice-registration-and-discovery-with-spring-cloud-and-netflix-s-eureka
 * --------------------------------------------------------------------------------------------
 * Created by 玄玉<https://www.xuanyuv.com/> on 2017/1/9 16:00.
 */
@EnableEurekaClient
@SpringBootApplication
public class ServiceServer01BootStarp {
    public static void main(String[] args) {
        SpringApplication.run(ServiceServer01BootStarp.class, args);
    }
}

package com.xuanyuv.demo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;

/**
 * 服务提供方暴露的数学运算服务
 * Created by 玄玉<https://www.xuanyuv.com/> on 2017/1/9 16:00.
 */
@RestController
public class CalculatorController {
    private final Logger logger = LoggerFactory.getLogger(getClass());
    @Resource
    private DiscoveryClient client;

    @RequestMapping("/add")
    public int add(int a, int b){
        //加运算
        int result = a + b;
        //输出服务信息
        ServiceInstance instance = client.getLocalServiceInstance();
        logger.info("uri={}，serviceId={}，result={}", instance.getUri(), instance.getServiceId(), result);
        //返回结果
        return result;
    }
}

package com.xuanyuv.demo;
import com.netflix.zuul.ZuulFilter;
import org.springframework.boot.SpringApplication;
import org.springframework.cloud.client.SpringCloudApplication;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
import org.springframework.context.annotation.Bean;

//注意不是@EnableZuulServer
@EnableZuulProxy
//注意这里使用了更加简化的@SpringCloudApplication
@SpringCloudApplication
public class ServiceGateway01BootStarp {
    /**
     * 这里的方法返回值，不能写成com.netflix.zuul.IZuulFilter
     * 可以写成com.netflix.zuul.ZuulFilter，或者com.xuanyuv.demo.GatewayFilter
     * 虽然语法上允许返回IZuulFilter，但实际测试发现返回IZuulFilter时，网关功能却没有生效
     */
    @Bean
    public ZuulFilter gatewayFilter() {
        return new GatewayFilter();
    }

    public static void main(String[] args) {
        SpringApplication.run(ServiceGateway01BootStarp.class, args);
    }
}

package com.xuanyuv.demo;
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.servlet.http.HttpServletRequest;

/**
 * 利用Zuul的过滤器，可以实现对外服务的安全控制
 * -------------------------------------------------------------------------
 * 这里实现了在请求被路由之前检查请求中是否有accesstoken参数
 * 若有就进行路由，若没有就拒绝访问，返回401 Unauthorized错误
 * http://127.0.0.1:4100/mycall/add?a=11&b=22：返回"权限不足"
 * http://127.0.0.1:4100/mycall/add?a=11&b=22&accesstoken=token：返回正常
 * -------------------------------------------------------------------------
 * Created by 玄玉<https://www.xuanyuv.com/> on 2017/1/14 15:05.
 */
public class GatewayFilter extends ZuulFilter {
    private Logger log = LoggerFactory.getLogger(getClass());

    /**
     * 如下所示，Zuul定义了四种不同生命周期的过滤器类型
     * pre    ：可以在请求被路由之前调用
     * routing：在路由请求时候被调用
     * post   ：在routing和error过滤器之后被调用
     * error  ：处理请求时发生错误时被调用
     */
    @Override
    public String filterType() {
        return "pre";
    }

    @Override
    public int filterOrder() {
        //通过int值来定义过滤器的执行顺序
        return 0;
    }

    @Override
    public boolean shouldFilter() {
        //设置该过滤器总是生效，即总是执行拦截请求
        return true;
    }

    /**
     * 过滤器的具体逻辑
     */
    @Override
    public Object run() {
        RequestContext ctx = RequestContext.getCurrentContext();
        HttpServletRequest request = ctx.getRequest();
        log.info(String.format("收到 %s 请求 %s", request.getMethod(), request.getRequestURL().toString()));
        Object accessToken = request.getParameter("accesstoken");
        if(accessToken == null) {
            ctx.getResponse().setContentType("text/html;charset=UTF-8");
            log.warn("accesstoken为空");
            //令zuul过滤该请求，不对其进行路由
            ctx.setSendZuulResponse(false);
            //设置其返回的错误码和报文体
            //这里没有设置应答码为401，是因为401会导致客户端走到它的断路器里面（HystrixCalculatorService）
            //所有设置为200，让应答报文体跳过客户端的断路器，返回给前台
            ctx.setResponseStatusCode(200);
            ctx.setResponseBody("权限不足");
            return null;
        }
        log.info("accesstoken验证通过");
        return null;
    }
}

package com.xuanyuv.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;

//开启Feign功能（无需显式@EnableCircuitBreaker，其已含此功能）
@EnableFeignClients
@EnableEurekaClient
@SpringBootApplication
public class ServiceClientBootStarp {
    public static void main(String[] args) {
        SpringApplication.run(ServiceClientBootStarp.class, args);
    }
}

package com.xuanyuv.demo.feign;
import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

//绑定該接口到服务网关的xuanyu-api-gateway服务，并通知Feign组件对该接口进行代理（不需要编写接口实现）
@FeignClient(value="xuanyu-api-gateway", fallback=CalculatorService.HystrixCalculatorService.class)
public interface CalculatorService {
    ////@PathVariable這種也是支持的
    //@RequestMapping(value="/mycall/add/{a}", method=RequestMethod.GET)
    //int myadd(@PathVariable("a") int a, @RequestParam("b") int b, @RequestParam("accesstoken") String accesstoken);

    //通过SpringMVC的注解来配置所綁定的服务下的具体实现
    @RequestMapping(value="/mycall/add", method=RequestMethod.GET)
    String myadd(@RequestParam("a") int a, @RequestParam("b") int b, @RequestParam("accesstoken") String accesstoken);

    /**
     * 这里采用和SpringCloud官方文档相同的做法，把fallback类作为内部类放入Feign接口中
     * http://cloud.spring.io/spring-cloud-static/Camden.SR6/#spring-cloud-feign-hystrix
     * （也可以外面独立定义该类，个人觉得没必要，这种东西写成内部类最合适）
     */
    @Component
    class HystrixCalculatorService implements CalculatorService {
        @Override
        public String myadd(@RequestParam("a") int a, @RequestParam("b") int b, @RequestParam("accesstoken") String accesstoken) {
            return "负999";
        }
    }
}

package com.xuanyuv.demo.feign;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;

/**
 * 服务调用方
 * Created by 玄玉<https://www.xuanyuv.com/> on 2017/1/10 18:23.
 */
@RestController
@RequestMapping("/demo/feign")
public class ConsumerController {
    @Resource
    private CalculatorService calculatorService;

    @RequestMapping("/toadd")
    String toadd(int a, int b, String accesstoken){
        return calculatorService.myadd(a, b, accesstoken);
    }
}