spring-cloud-gateway-mini

背景（Background）

为了帮助广大Spring Cloud Gateway爱好者更方便的学习SCG，了解spring-webflux和reactor-netty的使用，特意精简了SCG，保留了最核心的代码实现（只有2千多行代码），所以此项目叫做 spring-cloud-gateway-mini。
In order to help Spring Cloud Gateway enthusiasts learn SCG more conveniently and understand the use of spring-webflux and reactor-netty, SCG is deliberately simplified and the core code implementation is retained（just over 2,000 lines of code）, so this project is called spring-cloud-gateway-mini.

使用方法（Instruction Manual）

1.配置注册中心

由于我们pom.xml中依赖的是Consul，所以我们默认是将Consul作为注册中心，如果想尝试使用其他注册中心，那么需要替换如下的Maven依赖：
Since we depend on Consul in our pom.xml, we use Consul as the registry by default. If you want to try other registries, you need to replace the following Maven dependencies:

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-consul-all</artifactId>
            <version>3.1.0</version>
        </dependency>

如果我们用的是Consul，那么还需要修改 resources/application.yml 文件中的配置，配置成正确的Consul地址，相关配置如下：
If we are using Consul, we also need to modify the configuration in the resources/application.yml file to configure the correct Consul address. The relevant configuration is as follows:

spring:
  config:
    import: optional:consul:localhost:8500

上面的配置表明我们在本地就有个Consul服务。
The above configuration indicates that we have a Consul service locally.

2.配置路由

其实mini并没有实现SCG配置路由的能力，所以这块其实是需要在mini中编码实现，例如，在 RouteConfig 中的如下代码代码演示了如何创建一个通过负载均衡到达名为 spring-cloud-openfeign-provider 服务的路由：
In fact, mini does not have the ability to configure SCG routes, so it needs to be coded in mini. For example, the following code in RouteConfig demonstrates how to create a route to the service named spring-cloud-openfeign-provider through load balancing:

    @Bean
    public Route myThirdRoute() {
        try {
            return new Route("3", new URI("lb://spring-cloud-openfeign-provider"), new HashMap<>());
        } catch (URISyntaxException e) {
            throw new IllegalStateException(e);
        }
    }

可以看出所有在mini中的路由定义是通过代码来实现的。
It can be seen that all routing definitions in mini are implemented through code.

3.配置谓词

和路由一样，mini也没有实现SCG配置谓词的能力，所以这块其实是需要在mini中编码实现，例如，在 PredicateConfig 中的如下代码代码演示了如何创建一个匹配查询参数中包含 love 的谓词：
Like routing, mini does not have the ability to implement SCG configuration predicates, so it actually needs to be coded and implemented in mini. For example, the following code in PredicateConfig demonstrates how to create a predicate that matches the love contained in the query parameters:

    @Bean
    public Predicate myThirdPredicate(@Qualifier("myThirdRoute")final Route thirdRoute) {
        return new Predicate() {
            @Override
            public boolean match(ServerWebExchange exchange) {
                return exchange.getRequest().getQueryParams().containsKey("love");
            }

            @Override
            public Route getRoute() {
                return thirdRoute;
            }

            @Override
            public int getOrder() {
                return 2;
            }
        };
    }

我们可以注意到，上述的谓词和 第2步 创建的路由是绑定的，mini遵循了SCG的设计，一个谓词只能绑定到一个路由（但不同的谓词可以绑定到同一个路由）。
We can notice that the above predicates and the route created in step 2 are bound. Mini follows the design of SCG. A predicate can only be bound to one route (but different predicates can be bound to the same route).

4.运行mini

直接运行 SpringCloudGatewayMiniApplication 即可。
Just run SpringCloudGatewayMiniApplication directly.

特殊说明（Special Instructions）

1. 不用怀疑，spring-cloud-gateway-mini 中绝大部分代码来自 spring-cloud-gateway，请允许我擅自修改了部分类名。(No doubt, most of the code in spring-cloud-gateway-mini comes from spring-cloud-gateway, please allow me to modify some class names without authorization.)
2. spring-cloud-gateway-mini 只能用于学习，请勿用于生产或商业用途。（spring-cloud-gateway-mini can only be used for learning, not for production or commercial use）
3. spring-cloud-gateway-mini 中包含了 spring-cloud-gateway 的核心实现，如果有你认为的"核心实现"未在mini中体现，请联系作者或自行补充，毕竟每个人对spring-cloud-gateway理解会有一定程度的偏差。（spring-cloud-gateway-mini contains the core implementation of spring-cloud-gateway. If there is a "core implementation" that you think is not reflected in the mini, please contact the author or add it yourself. After all, everyone is not interested in spring-cloud-gateway. There will be a certain degree of deviation in understanding）
4. 很遗憾，如有侵权行为，请第一时间联系作者：835576511@qq.com、dubbocommitter@gmail.com。（Unfortunately, if there is any infringement, please contact the author as soon as possible: 835576511@qq.com, dubbocommitter@gmail.com）