From a15ab195c64fe38c9bb19c348ebd6b752d66a00e Mon Sep 17 00:00:00 2001
From: lazy <65394407+liuzg-coder@users.noreply.github.com>
Date: Wed, 1 Nov 2023 07:28:06 -0500
Subject: [PATCH] extract variables (#13284)

---
 .../apache/dubbo/common/constants/CommonConstants.java    | 4 ++++
 .../java/org/apache/dubbo/config/ReferenceConfig.java     | 8 +++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/dubbo-common/src/main/java/org/apache/dubbo/common/constants/CommonConstants.java b/dubbo-common/src/main/java/org/apache/dubbo/common/constants/CommonConstants.java
index c3aea739ee..b75b5a53d0 100644
--- a/dubbo-common/src/main/java/org/apache/dubbo/common/constants/CommonConstants.java
+++ b/dubbo-common/src/main/java/org/apache/dubbo/common/constants/CommonConstants.java
@@ -646,4 +646,8 @@ public interface CommonConstants {
     String SERVICE_DEPLOYER_ATTRIBUTE_KEY = "serviceDeployer";
 
     String DUBBO_MANUAL_REGISTER_KEY = "dubbo.application.manual-register";
+
+    String POD_NAMESPACE = "POD_NAMESPACE";
+
+    String CLUSTER_DOMAIN = "CLUSTER_DOMAIN";
 }
diff --git a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java
index 9d8280d312..343f8d0ac1 100644
--- a/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java
+++ b/dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java
@@ -66,6 +66,7 @@ import java.util.Set;
 import java.util.TreeSet;
 
 import static org.apache.dubbo.common.constants.CommonConstants.ANY_VALUE;
+import static org.apache.dubbo.common.constants.CommonConstants.CLUSTER_DOMAIN;
 import static org.apache.dubbo.common.constants.CommonConstants.CLUSTER_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.COMMA_SEPARATOR;
 import static org.apache.dubbo.common.constants.CommonConstants.COMMA_SEPARATOR_CHAR;
@@ -77,6 +78,7 @@ import static org.apache.dubbo.common.constants.CommonConstants.LOCALHOST_VALUE;
 import static org.apache.dubbo.common.constants.CommonConstants.MESH_ENABLE;
 import static org.apache.dubbo.common.constants.CommonConstants.METHODS_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.MONITOR_KEY;
+import static org.apache.dubbo.common.constants.CommonConstants.POD_NAMESPACE;
 import static org.apache.dubbo.common.constants.CommonConstants.PROXY_CLASS_REF;
 import static org.apache.dubbo.common.constants.CommonConstants.REVISION_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.SEMICOLON_SPLIT_PATTERN;
@@ -504,21 +506,21 @@ public class ReferenceConfig<T> extends ReferenceConfigBase<T> {
 
         // get pod namespace from env if annotation not present the provider namespace
         if (StringUtils.isEmpty(podNamespace)) {
-            if (StringUtils.isEmpty(System.getenv("POD_NAMESPACE"))) {
+            if (StringUtils.isEmpty(System.getenv(POD_NAMESPACE))) {
                 if (logger.isWarnEnabled()) {
                     logger.warn(CONFIG_FAILED_LOAD_ENV_VARIABLE, "", "", "Can not get env variable: POD_NAMESPACE, it may not be running in the K8S environment , " +
                             "finally use 'default' replace.");
                 }
                 podNamespace = "default";
             } else {
-                podNamespace = System.getenv("POD_NAMESPACE");
+                podNamespace = System.getenv(POD_NAMESPACE);
             }
         }
 
         // In mesh mode, providedBy equals K8S Service name.
         String providedBy = referenceParameters.get(PROVIDED_BY);
         // cluster_domain default is 'cluster.local',generally unchanged.
-        String clusterDomain = Optional.ofNullable(System.getenv("CLUSTER_DOMAIN")).orElse(DEFAULT_CLUSTER_DOMAIN);
+        String clusterDomain = Optional.ofNullable(System.getenv(CLUSTER_DOMAIN)).orElse(DEFAULT_CLUSTER_DOMAIN);
         // By VirtualService and DestinationRule, envoy will generate a new route rule,such as 'demo.default.svc.cluster.local:80',the default port is 80.
         Integer meshPort = Optional.ofNullable(getProviderPort()).orElse(DEFAULT_MESH_PORT);
         // DubboReference default is -1, process it.