增加 yudao-spring-boot-starter-env 组件，完成 tag 请求头的读取到上下文

yudao-framework/yudao-spring-boot-starter-env/src/main/java/cn/iocoder/yudao/framework/env/config/EnvProperties.java

@@ -0,0 +1,18 @@
+package cn.iocoder.yudao.framework.env.config;
+
+import lombok.Data;
+
+/**
+ * 环境
+ *
+ * @author 芋道源码
+ */
+@Data
+public class EnvProperties {
+
+    /**
+     * 环境标签
+     */
+    private String tag;
+
+}

yudao-framework/yudao-spring-boot-starter-env/src/main/java/cn/iocoder/yudao/framework/env/config/YudaoEnvWebAutoConfiguration.java

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+package cn.iocoder.yudao.framework.env.config;
+
+import cn.iocoder.yudao.framework.common.enums.WebFilterOrderEnum;
+import cn.iocoder.yudao.framework.env.core.web.EnvWebFilter;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
+import org.springframework.boot.web.servlet.FilterRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@ConditionalOnWebApplication(type = ConditionalOnWebApplication.Type.SERVLET)
+public class YudaoEnvWebAutoConfiguration {
+
+    /**
+     * 创建 {@link EnvWebFilter} Bean
+     */
+    @Bean
+    public FilterRegistrationBean<EnvWebFilter> envWebFilterFilter() {
+        EnvWebFilter filter = new EnvWebFilter();
+        FilterRegistrationBean<EnvWebFilter> bean = new FilterRegistrationBean<>(filter);
+        bean.setOrder(WebFilterOrderEnum.ENV_TAG_FILTER);
+        return bean;
+    }
+
+}

yudao-framework/yudao-spring-boot-starter-env/src/main/java/cn/iocoder/yudao/framework/env/core/context/EnvContextHolder.java

@@ -0,0 +1,39 @@
+package cn.iocoder.yudao.framework.env.core.context;
+
+import cn.hutool.core.collection.CollUtil;
+import com.alibaba.ttl.TransmittableThreadLocal;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 开发环境上下文
+ *
+ * @author 芋道源码
+ */
+public class EnvContextHolder {
+
+    /**
+     * 标签的上下文
+     *
+     * 使用 {@link List} 的原因，可能存在多层设置或者清理
+     */
+    private static final ThreadLocal<List<String>> tagContext = TransmittableThreadLocal.withInitial(ArrayList::new);
+
+    public static void setTag(String tag) {
+        tagContext.get().add(tag);
+    }
+
+    public static String getTag() {
+        return CollUtil.getLast(tagContext.get());
+    }
+
+    public static void removeTag() {
+        List<String> tags = tagContext.get();
+        if (CollUtil.isEmpty(tags)) {
+            return;
+        }
+        tags.remove(tags.size() - 1);
+    }
+
+}

yudao-framework/yudao-spring-boot-starter-env/src/main/java/cn/iocoder/yudao/framework/env/core/package-info.java

@@ -0,0 +1 @@
+package cn.iocoder.yudao.framework.env.core;

yudao-framework/yudao-spring-boot-starter-env/src/main/java/cn/iocoder/yudao/framework/env/core/util/EnvUtils.java

@@ -0,0 +1,26 @@
+package cn.iocoder.yudao.framework.env.core.util;
+
+import cn.hutool.core.net.NetUtil;
+
+import javax.servlet.http.HttpServletRequest;
+import java.util.Objects;
+
+/**
+ * 环境 Utils
+ *
+ * @author 芋道源码
+ */
+public class EnvUtils {
+
+    private static final String HEADER_DUBBO_TAG = "tag";
+
+    private static final String HOST_NAME_VALUE = "${HOSTNAME}";
+
+    public static String getTag(HttpServletRequest request) {
+        String tag = request.getHeader(HEADER_DUBBO_TAG);
+        // 如果请求的是 "${HOSTNAME}"，则解析成对应的本地主机名
+        // 目的：特殊逻辑，解决 IDEA Rest Client 不支持环境变量的读取，所以就服务器来做
+        return Objects.equals(tag, HOST_NAME_VALUE) ? NetUtil.getLocalHostName() : tag;
+    }
+
+}

yudao-framework/yudao-spring-boot-starter-env/src/main/java/cn/iocoder/yudao/framework/env/core/web/EnvWebFilter.java

@@ -0,0 +1,41 @@
+package cn.iocoder.yudao.framework.env.core.web;
+
+import cn.hutool.core.util.StrUtil;
+import cn.iocoder.yudao.framework.env.core.context.EnvContextHolder;
+import cn.iocoder.yudao.framework.env.core.util.EnvUtils;
+import org.springframework.web.filter.OncePerRequestFilter;
+
+import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * 环境的 {@link javax.servlet.Filter} 实现类
+ * 当有 tag 请求头时，设置到 {@link EnvContextHolder} 的标签上下文
+ *
+ * @author 芋道源码
+ */
+public class EnvWebFilter extends OncePerRequestFilter {
+
+    @Override
+    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
+            throws ServletException, IOException {
+        // 如果没有 tag，则走默认的流程
+        String tag = EnvUtils.getTag(request);
+        if (StrUtil.isEmpty(tag)) {
+            chain.doFilter(request, response);
+            return;
+        }
+
+        // 如果有 tag，则设置到上下文
+        EnvContextHolder.setTag(tag);
+        try {
+            chain.doFilter(request, response);
+        } finally {
+            EnvContextHolder.removeTag();
+        }
+    }
+
+}

yudao-framework/yudao-spring-boot-starter-env/src/main/java/cn/iocoder/yudao/framework/env/package-info.java

@@ -0,0 +1,7 @@
+/**
+ * 开发环境拓展，实现类似阿里的特性环境的能力
+ * 1. https://segmentfault.com/a/1190000018022987
+ *
+ * @author 芋道源码
+ */
+package cn.iocoder.yudao.framework.env;

yudao-framework/yudao-spring-boot-starter-env/src/main/resources/META-INF/spring.factories

@@ -0,0 +1,2 @@
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+  cn.iocoder.yudao.framework.env.config.YudaoEnvWebAutoConfiguration