【Spring Cloud学习之四】Zuul网关

环境
　　eclipse 4.7
　　jdk 1.8
　　Spring Boot 1.5.2
　　Spring Cloud 1.2

一、接口网关
接口网关：拦截所有的请求，交由接口网关，然后接口网关进行转发，类似nginx反向代理。

二、Zuul
Zuul的主要功能是路由转发和过滤器。路由功能是微服务的一部分，比如／api/user转发到到user服务，/api/shop转发到到shop服务， 类似于nginx转发。
zuul默认和Ribbon结合实现了负载均衡的功能。

三、搭建zuul网关工程(eureka client)
1、新建maven工程：service-zuul

2、pom.xml

<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.wjy</groupId>
    <artifactId>service-zuul</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.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>
    </properties>

    <dependencies>
        <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>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</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>Dalston.RC1</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>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

</project>

3、application.yml

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8888/eureka/
server:
  port: 8769
spring:
  application:
    name: service-zuul
zuul:
  routes:
    api-a:
      path: /api-member/**
      service-id: service-member
    api-b:
      path: /api-order/**
      service-id: service-order

4、路由转发
启动类需要加@EnableZuulProxy 开启路由转发功能

package com.wjy;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;

@SpringBootApplication
@EnableEurekaClient
@EnableZuulProxy
public class ZuulApp {
    public static void main(String[] args) {
        SpringApplication.run(ZuulApp.class, args);
    }

}

修改MemberController：

package com.wjy.controller;

import java.util.ArrayList;
import java.util.List;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MemberController {

    @Value("${server.port}")
    private String serverPort;

    @RequestMapping("/getUserList")
    public List<String> getUserList() {
        List<String> listUser = new ArrayList<String>();
        listUser.add("zhangsan");
        listUser.add("lisi");
        listUser.add("wjy");
        listUser.add("端口号:"+serverPort);
        return listUser;
    }

    @RequestMapping("/getMemberServiceApi")
    public String getMemberServiceApi() {
        return "this is 会员 服务工程";
    }

}

修改OrderController：

package com.wjy.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.wjy.service.OrderMemberService;

@RestController
public class OrderController {
    @Autowired
    private OrderMemberService orderMemberService;

    @RequestMapping("/getOrderUserAll")
    public List<String> getOrderUserAll() {
        System.out.println("订单服务开始调用会员服务");
        return orderMemberService.getOrderUserAll();

    }

    @RequestMapping("/getOrderServiceApi")
    public String getOrderServiceApi() {
        return "this is 订单服务工程";
    }
}

测试验证：

发送请求http://127.0.0.1:8769/api-member/getMemberServiceApi转发到http://127.0.0.1:8762/getMemberServiceApi

发送请求http://127.0.0.1:8769/api-order/getOrderServiceApi转发到http://127.0.0.1:8764/getOrderServiceApi

6、服务过滤类：

package com.wjy;

import javax.servlet.http.HttpServletRequest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;

@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;
    }

    public boolean shouldFilter() {
        return true;
    }

    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");
        String refer = request.getHeader("refer");

        if (accessToken != null) {
            return null;
        }
        log.warn("token is empty");
        ctx.setSendZuulResponse(false);
        ctx.setResponseStatusCode(401);
        try {
            ctx.getResponse().getWriter().write("token is empty");
        } catch (Exception e) {
        }
        return null;

    }
}

测试验证：

发送请求http://127.0.0.1:8769/api-member/getUserList?token=123456789

发送请求http://127.0.0.1:8769/api-member/getUserList