Address comments.

Author: shunping

buildSrc/build.gradle.kts

@@ -18,8 +18,7 @@
 import java.net.HttpURLConnection
 import java.net.URL
 
-fun checkMavenCentralAccessibility(): Boolean {
-  val testUrl = "https://repo.maven.apache.org/maven2/org/slf4j/slf4j-api/1.7.2/slf4j-api-1.7.2.pom"
+fun checkMavenCentralAccessibility(testUrl: String): Boolean {
   val accessible = try {
     val connection = URL(testUrl).openConnection() as HttpURLConnection
     connection.requestMethod = "GET"
@@ -40,8 +39,10 @@ fun checkMavenCentralAccessibility(): Boolean {
   return accessible
 }
 
-val isMavenAccessible = checkMavenCentralAccessibility()
-val mavenCentralMirrorUrl = "https://maven-central.storage-download.googleapis.com/maven2/"
+val mavenCentralTestUrl = providers.gradleProperty("mavenCentralTestUrl").getOrElse("https://repo.maven.apache.org/maven2/org/slf4j/slf4j-api/1.7.2/slf4j-api-1.7.2.pom")
+val mavenCentralMirrorUrl = providers.gradleProperty("mavenCentralMirrorUrl").getOrElse("https://maven-central.storage-download.googleapis.com/maven2/")
+
+val isMavenAccessible = checkMavenCentralAccessibility(mavenCentralTestUrl)
 
 // Plugins for configuring _this build_ of the module
 plugins {

buildSrc/src/main/groovy/org/apache/beam/gradle/Repositories.groovy

@@ -26,11 +26,11 @@ class Repositories {
 
   private static Boolean isMavenAccessible = null
 
-  static synchronized boolean checkMavenCentral() {
+  static synchronized boolean checkMavenCentral(Project project) {
     if (isMavenAccessible != null) {
       return isMavenAccessible
     }
-    def testUrl = "https://repo.maven.apache.org/maven2/org/slf4j/slf4j-api/1.7.2/slf4j-api-1.7.2.pom"
+    def testUrl = project.findProperty("mavenCentralTestUrl") ?: "https://repo.maven.apache.org/maven2/org/slf4j/slf4j-api/1.7.2/slf4j-api-1.7.2.pom"
     try {
       def url = new URL(testUrl)
       def connection = (HttpURLConnection) url.openConnection()
@@ -47,12 +47,13 @@ class Repositories {
     if (isMavenAccessible) {
       println "Maven Central is accessible. Using default repositories."
     } else {
-      println "Maven Central is not accessible. Falling back to Google Maven Mirror."
+      println "Maven Central is not accessible. Redirecting to Google Maven Mirror."
     }
     return isMavenAccessible
   }
 
   static void register(Project project) {
+    def mirrorUrl = project.findProperty("mavenCentralMirrorUrl") ?: "https://maven-central.storage-download.googleapis.com/maven2/"
 
     project.repositories {
       maven { url project.offlineRepositoryRoot }
@@ -66,10 +67,10 @@ class Repositories {
         return
       }
 
-      if (checkMavenCentral()) {
+      if (checkMavenCentral(project)) {
         mavenCentral()
       } else {
-        maven { url "https://maven-central.storage-download.googleapis.com/maven2/" }
+        maven { url mirrorUrl }
       }
       mavenLocal()
 
@@ -102,10 +103,10 @@ class Repositories {
     project.offlineDependencies {
       repositories {
         mavenLocal()
-        if (checkMavenCentral()) {
+        if (checkMavenCentral(project)) {
           mavenCentral()
         } else {
-          maven { url "https://maven-central.storage-download.googleapis.com/maven2/" }
+          maven { url mirrorUrl }
         }
         maven { url "https://plugins.gradle.org/m2/" }
         maven { url "https://repo.spring.io/plugins-release" }

gradle.properties

@@ -44,3 +44,7 @@ flink_versions=1.17,1.18,1.19,1.20,2.0
 spark_versions=3,4
 # supported python versions
 python_versions=3.10,3.11,3.12,3.13,3.14
+
+# Maven Central fallback mirror and connectivity test URL
+mavenCentralMirrorUrl=https://maven-central.storage-download.googleapis.com/maven2/
+mavenCentralTestUrl=https://repo.maven.apache.org/maven2/org/slf4j/slf4j-api/1.7.2/slf4j-api-1.7.2.pom

settings.gradle.kts

@@ -18,8 +18,11 @@
 import com.gradle.enterprise.gradleplugin.internal.extension.BuildScanExtensionWithHiddenFeatures
 
 pluginManagement {
+    val mavenCentralTestUrl = settings.providers.gradleProperty("mavenCentralTestUrl").getOrElse("https://repo.maven.apache.org/maven2/org/slf4j/slf4j-api/1.7.2/slf4j-api-1.7.2.pom")
+    val mavenCentralMirrorUrl = settings.providers.gradleProperty("mavenCentralMirrorUrl").getOrElse("https://maven-central.storage-download.googleapis.com/maven2/")
+
     val isMavenAccessible = try {
-        val connection = java.net.URL("https://repo.maven.apache.org/maven2/org/slf4j/slf4j-api/1.7.2/slf4j-api-1.7.2.pom").openConnection() as java.net.HttpURLConnection
+        val connection = java.net.URL(mavenCentralTestUrl).openConnection() as java.net.HttpURLConnection
         connection.requestMethod = "GET"
         connection.setRequestProperty("User-Agent", "Gradle")
         connection.connectTimeout = 2000
@@ -29,7 +32,6 @@ pluginManagement {
     } catch (e: Exception) {
         false
     }
-    val mavenCentralMirrorUrl = "https://maven-central.storage-download.googleapis.com/maven2/"
 
     if (isMavenAccessible) {
         logger.lifecycle("Maven Central is accessible. Using default repositories for settings plugins.")