Use a temporary repository location to download certain ecj versions ("drops") (#14703)

Author: dweiss

gradle/libs.versions.toml

@@ -8,8 +8,8 @@ assertj = "3.27.3"
 commons-codec = "1.18.0"
 # benchmark/ bzip2 compression
 commons-compress = "1.27.1"
-# @keep This version refers to ECJ batch compiler from p2 repositories ("drops").
-ecjP2Drop = "ecj-4.36M1"
+# See ecj-lint.gradle (used for more linting).
+ecj = "4.36M1"
 # java linting
 errorprone = "2.38.0"
 # markdown documentation generation
@@ -67,6 +67,7 @@ antlr-runtime = { module = "org.antlr:antlr4-runtime", version.ref = "antlr" }
 assertj = { module = "org.assertj:assertj-core", version.ref = "assertj" }
 commons-codec = { module = "commons-codec:commons-codec", version.ref = "commons-codec" }
 commons-compress = { module = "org.apache.commons:commons-compress", version.ref = "commons-compress" }
+ecj = { module = "org.eclipse.jdt:ecj", version.ref = "ecj" }
 errorprone = { module = "com.google.errorprone:error_prone_core", version.ref = "errorprone" }
 flexmark-core = { module = "com.vladsch.flexmark:flexmark", version.ref = "flexmark" }
 flexmark-ext-abbreviation = { module = "com.vladsch.flexmark:flexmark-ext-abbreviation", version.ref = "flexmark" }

gradle/validation/ecj-lint.gradle

@@ -17,41 +17,45 @@
 
 // This adds 'ecjLint' task.
 
-configure(rootProject) {
-  apply plugin: deps.plugins.undercouch.download.get().pluginId
-
-  def ecjVersion = deps.versions.ecjP2Drop.get()
-  def ecjDropJar = project.layout.buildDirectory.file("ecj-drop/${ecjVersion}.jar")
-  def downloadEcjDrop = tasks.register("downloadEcjDrop", Download, {
-    src "https://www.eclipse.org/downloads/download.php?r=1&file=/eclipse/downloads/drops4/S-4.36M1-202504031800/${ecjVersion}.jar"
-    dest project.layout.buildDirectory.dir("ecj-drop")
-    overwrite false
-    onlyIf {
-      !ecjDropJar.get().asFile.exists()
-    }
-  })
-
-  configurations {
-    ecjDropDeps
-  }
-
-  artifacts {
-    add("ecjDropDeps", ecjDropJar, {
-      builtBy downloadEcjDrop
-    })
-  }
-}
-
 def resources = scriptResources(buildscript)
 
 allprojects {
   plugins.withType(JavaPlugin).configureEach {
+
+    // Use Lucene's storage space for "drop" versions that are ahead
+    // of official Maven publications.
+    //
+    // Drop versions are at:
+    // https://www.eclipse.org/downloads/download.php?r=1&file=/eclipse/downloads/drops4/S-4.36M1-202504031800/ecj-${ecjVersion}.jar
+    boolean useDropMirror = deps.versions.ecj.get() in ["4.36M1"]
+    if (useDropMirror) {
+      repositories {
+        exclusiveContent {
+          forRepository {
+            ivy {
+              url = 'https://s3.amazonaws.com/lucene-testdata/temp-repo/ecj/'
+              patternLayout {
+                artifact "[artifact]-[revision](.[ext])"
+                m2compatible = true
+              }
+              metadataSources {
+                it.artifact()
+              }
+            }
+          }
+          filter {
+            includeGroup "org.eclipse.jdt"
+          }
+        }
+      }
+    }
+
     configurations {
       ecjDeps
     }
 
     dependencies {
-      ecjDeps project(path: ":", configuration: "ecjDropDeps")
+      ecjDeps deps.ecj
     }
 
     def ecjConfiguration = configurations.ecjDeps