一 Zuul簡介

Zuul的主要功能是路由轉發和過濾器。路由功能是微服務的一部分，比如／user/**轉發到到user服務，/api/**轉發到到api服務。zuul默認和Ribbon結合實現了負載均衡的功能。

二 Zuul的路由功能

創建一個Module 叫zuul

創建完成之後的pom如下：

<?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>

    <groupId>com.hmzj</groupId>
    <artifactId>zuul</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <
 
name>zuul</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
 

        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Finchley.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-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>


</project>

創建application.yml

server:
  port: 8062
spring:
  application:
    name: zuul
eureka:
  instance:
    prefer-ip-address: true
    instance-id: ${spring.cloud.client.ip-address}:${spring.application.name}:${server.port}
  client:
    serviceUrl:
      defaultZone: http://**:**@192.168.31.54:8060/eureka/
zuul:
  routes:
    user: #localhost:8062/user/**中的user
      path: /user/** #轉發user/下的所有請求
      serviceId: callcenter-user #服務名稱
    freeswitch:
      path: /freeswitch/**
      serviceId: callcenter-freeswitch
    api:
      path: /api/**
      serviceId: callcenter-api

其中路由部分就是routes下面的部分

啟動服務

訪問http://localhost:8062/user/test/sayHello/pyq 8062是zuul的端口

二 Zuul的過濾器功能

在根目錄下新建MyFilter.java

package com.hmzj.zuul;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;

@Component
public class MyFilter extends ZuulFilter {

    private static Logger log = LoggerFactory.getLogger(MyFilter.class);

    @Override
    public String filterType() {
        return "pre";
    }

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

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

    @Override
    public Object run() {
        RequestContext ctx = RequestContext.getCurrentContext();
        HttpServletRequest request = ctx.getRequest();
        log.info(String.format("%s >>> %s", request.getMethod(), request.getRequestURL().toString()));
        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 (Exception e){}

            return false;
        }
        log.info("ok");
        return true;
    }
}

此處通過zuul來轉發服務時都要經過此過濾器

FilterType：返回一個字符串代表過濾器的類型，在zuul中定義了四種不同生命周期的過濾器類型，具體如下：

• pre：路由之前
• routing：路由之時
• post： 路由之後
• error：發送錯誤調用
• filterOrder：過濾的順序
• shouldFilter：這裏可以寫邏輯判斷，是否要過濾，本文true,永遠過濾。
• run：過濾器的具體邏輯。可用很復雜，包括查sql，nosql去判斷該請求到底有沒有權限訪問。

第四篇：路由網關(zuul)