1. system 提供 OAuth2TokenApi 接口

2. gateway 通过 feign 引入 OAuth2TokenApi 接口

yudao-gateway/pom.xml

@@ -16,6 +16,13 @@
     <url>https://github.com/YunaiV/yudao-cloud</url>
 
     <dependencies>
+        <!-- 业务组件 -->
+        <dependency>
+            <groupId>cn.iocoder.cloud</groupId>
+            <artifactId>yudao-module-system-api</artifactId>
+            <version>${revision}</version>
+        </dependency>
+
         <!-- Gateway 网关相关 -->
         <dependency>
             <groupId>org.springframework.cloud</groupId>
@@ -28,6 +35,11 @@
             <artifactId>spring-cloud-starter-loadbalancer</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-openfeign</artifactId>
+        </dependency>
+
         <!-- Registry 注册中心相关 -->
         <dependency>
             <groupId>com.alibaba.cloud</groupId>

yudao-gateway/src/main/java/cn/iocoder/yudao/gateway/GatewayServerApplication.java

@@ -1,9 +1,14 @@
 package cn.iocoder.yudao.gateway;
 
+import cn.iocoder.yudao.module.system.api.auth.OAuth2TokenApi;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.openfeign.EnableFeignClients;
 
 @SpringBootApplication
+@EnableFeignClients(clients = {
+        OAuth2TokenApi.class
+}) // TODO 芋艿：需要改下
 public class GatewayServerApplication {
 
     public static void main(String[] args) {

yudao-gateway/src/main/java/cn/iocoder/yudao/gateway/filter/TokenAuthenticationFilter.java

@@ -0,0 +1,45 @@
+package cn.iocoder.yudao.gateway.filter;
+
+import cn.iocoder.yudao.module.system.api.auth.OAuth2TokenApi;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.cloud.gateway.filter.GatewayFilterChain;
+import org.springframework.cloud.gateway.filter.GlobalFilter;
+import org.springframework.core.Ordered;
+import org.springframework.http.HttpHeaders;
+import org.springframework.stereotype.Component;
+import org.springframework.web.server.ServerWebExchange;
+import reactor.core.publisher.Mono;
+
+import javax.annotation.Resource;
+import java.util.function.Consumer;
+
+/**
+ * Token 过滤器，验证 token 的有效性
+ * 1. 验证通过时，将 userId、userType、tenantId 通过 Header 转发给服务
+ * 2. 验证不通过，还是会转发给服务。因为，接口是否需要登录的校验，还是交给服务自身处理
+ *
+ * @author 芋道源码
+ */
+@Component // TODO 芋艿：要改成 configuration
+public class TokenAuthenticationFilter implements GlobalFilter, Ordered {
+
+    @Resource
+    private OAuth2TokenApi oauth2TokenApi;
+
+    @Override
+    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
+        exchange = exchange.mutate().request(r -> r.headers(new Consumer<HttpHeaders>() {
+            @Override
+            public void accept(HttpHeaders headers) {
+                headers.set("user-id", "1");
+            }
+        })).build();
+        return chain.filter(exchange);
+    }
+
+    @Override
+    public int getOrder() {
+        return -100; // 和 Spring Security Filter 的顺序对齐
+    }
+
+}

yudao-gateway/src/main/java/cn/iocoder/yudao/gateway/util/SecurityFrameworkUtils.java

@@ -0,0 +1,39 @@
+package cn.iocoder.yudao.gateway.util;
+
+import org.springframework.util.StringUtils;
+import org.springframework.web.server.ServerWebExchange;
+
+/**
+ * 安全服务工具类
+ *
+ * copy from yudao-spring-boot-starter-security 的 SecurityFrameworkUtils 类
+ *
+ * @author 芋道源码
+ */
+public class SecurityFrameworkUtils {
+
+    public static final String AUTHORIZATION_HEADER = "Authorization";
+
+    public static final String AUTHORIZATION_BEARER = "Bearer";
+
+    private SecurityFrameworkUtils() {}
+
+    /**
+     * 从请求中，获得认证 Token
+     *
+     * @param exchange 请求
+     * @return 认证 Token
+     */
+    public static String obtainAuthorization(ServerWebExchange exchange) {
+        String authorization = exchange.getRequest().getHeaders().getFirst(AUTHORIZATION_HEADER);
+        if (!StringUtils.hasText(authorization)) {
+            return null;
+        }
+        int index = authorization.indexOf(AUTHORIZATION_BEARER + " ");
+        if (index == -1) { // 未找到
+            return null;
+        }
+        return authorization.substring(index + 7).trim();
+    }
+
+}