SpringCloud的学习记录(7)

这一章节讲zuul的使用.

在我们生成的Demo项目上右键点击New->Module->spring Initializr, 然后next, 填写Group和Artifact等信息，

这里Artifact填写eurekazuul, 再次next, 选择内容如下的pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.xum</groupId>
    <artifactId>eureka-zuul</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>eureka-zuul</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-turbine</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>

</project>

eureka-zuul模型结构如下:

1. 首先是EurekaZuulApplication.java内容如下:

package com.xum.eurekazuul;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.hystrix.dashboard.EnableHystrixDashboard;
import org.springframework.cloud.netflix.turbine.EnableTurbine;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;

@SpringBootApplication
@EnableZuulProxy  // 这里是启用zuul路由的注解
@EnableHystrixDashboard
@EnableTurbine
public class EurekaZuulApplication {

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

}

2. application.yml内容如下:

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
server:
  port: 8773
zuul:   // 这里定义了两个api接口的路由, 一个指向ribbon-consumer, 一个指向fegin-client
  routes:
    api-a:
      path: /api-a/**
      serviceId: ribbon-consumer
    api-b:
      path: /api-b/**
      serviceId: fegin-client
turbine:
  aggregator:
    cluster-config: default
  app-config: '*'
  cluster-name-expression: new String("default")
spring:
  application:
    name: eureka-zuul
management:
  endpoint:
    health:
      show-details: always
  endpoints:
    web:
      exposure:
        include: '*'

3. 然后是PermissionsFilter.java内容如下:

package com.xum.eurekazuul.filter;

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 static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;

@Component
public class PermissionsFilter extends ZuulFilter {

    private static final Logger LOG = LoggerFactory.getLogger(PermissionsFilter.class);

    @Override
    public String filterType() {
        return PRE_TYPE;
    }

    @Override
    public int filterOrder() {
        return 0;
    }

    @Override
    public boolean shouldFilter() {
        return true;
        /*RequestContext ctx = RequestContext.getCurrentContext();
        return (boolean) ctx.get("isSuccess");*/
    }

    @Override
    public Object run() throws ZuulException {
        RequestContext ctx = RequestContext.getCurrentContext();
        HttpServletRequest request = ctx.getRequest();

        LOG.info(String.format("%s AccessNameFilter request to %s", request.getMethod(), request.getRequestURL().toString()));
        String name = request.getParameter("name");// 获取请求的参数
        if(null != name && "xum".equalsIgnoreCase(name)) { // 在向eureka-client项目里调用api的时候,检查带的name内容是否是xum 
            ctx.setSendZuulResponse(true);
            ctx.setResponseStatusCode(200);
            ctx.set("isSuccess", true);
            return null;
        }else{
            ctx.setSendZuulResponse(false);
            ctx.setResponseStatusCode(401);
            ctx.setResponseBody("{\"result\":\"name is not correct!\"}");
            ctx.set("isSuccess", false);
            return null;
        }
    }
}

4. 其次就是ApiFallbackProvider.java内容如下:

package com.xum.eurekazuul.provider;

import com.netflix.hystrix.exception.HystrixTimeoutException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

@Component
public class ApiFallbackProvider implements FallbackProvider {

    private static final Logger LOG = LoggerFactory.getLogger(ApiFallbackProvider.class);

    @Override
    public String getRoute() {
        LOG.info("ApiFallbackProvider=>getRoute");
        return "*";
    }

    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        LOG.info(String.format("route:%s,exceptionType:%s,stackTrace:%s", route, cause.getClass().getName(), cause.getStackTrace()));
        String message = "";
        if (cause instanceof HystrixTimeoutException) {
            message = "Timeout";
        } else {
            message = "Service exception";
        }
        return fallbackResponse(message);
    }

    public ClientHttpResponse fallbackResponse(String message) {

        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                LOG.info("ApiFallbackProvider=>ClientHttpResponse=>getStatusCode");
                return HttpStatus.OK;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                LOG.info("ApiFallbackProvider=>ClientHttpResponse=>getRawStatusCode");
                return 200;
            }

            @Override
            public String getStatusText() throws IOException {
                LOG.info("ApiFallbackProvider=>ClientHttpResponse=>getStatusText");
                return "OK";
            }

            @Override
            public void close() {
                LOG.info("ApiFallbackProvider=>ClientHttpResponse=>close");
            }

            @Override
            public InputStream getBody() throws IOException {
                LOG.info("ApiFallbackProvider=>ClientHttpResponse=>getBody");
                String bodyText = String.format("{\"code\": 999,\"message\": \"Service unavailable:%s\"}", message);
                return new ByteArrayInputStream(bodyText.getBytes());
            }

            @Override
            public HttpHeaders getHeaders() {
                LOG.info("ApiFallbackProvider=>ClientHttpResponse=>getHeaders");
                HttpHeaders headers = new HttpHeaders();
                headers.setContentType(MediaType.APPLICATION_JSON);
                return headers;
            }
        };
    }
}

顺序启动一下项目:

1. eureka-server

2. config-server

3. eureka-client

4. fegin-client

5. ribbon-consumer

6. zuul-client

然后再浏览器或则post man中输入http://localhost:8773/api-a/ribbonconsumer/test?name=xum, 显示内容如下:

在eureka-zuul项目里Event log打印出如下类似的log：

2019-03-31 14:52:51.881  INFO 1976 --- [nio-8773-exec-9] c.x.eurekazuul.filter.PermissionsFilter  : POST AccessNameFilter request to http://localhost:8773/api-a/ribbonconsumer/test

当输入http://localhost:8773/api-a/ribbonconsumer/test, 不带任何参数的时候, 显示内容如下, 路由网关提示name不正确.

然后再post man中输入http://localhost:8773/api-b/feign/feignconsumer?name=xum, 内容如下:

也能在eureka-client项目的Event log里看到如下类似的log:

2019-03-31 14:58:27.395  INFO 1976 --- [nio-8773-exec-5] c.x.eurekazuul.filter.PermissionsFilter  : POST AccessNameFilter request to http://localhost:8773/api-b/feign/feignconsumer

相同的道理, 如果参数没有name或则name只不对, 路由网关都会提示出错.

当eureka-client项目没有启动的时候, Hyrtrix会进行相应自我保护.