From 94079b9c619bf949a5ea03cee7d4dc2ae642d7b5 Mon Sep 17 00:00:00 2001
From: Reid Baker <reidbaker@google.com>
Date: Thu, 9 Nov 2023 13:38:18 -0500
Subject: [PATCH] Improved Java version parsing (#138155)

Fixes #135402
Add fallback logic for a different format of java version output and handle no patch versions.
Add tests for new logic output to prevent regressions.
---
 .../flutter_tools/lib/src/android/java.dart   | 11 ++++++++++
 .../test/general.shard/android/java_test.dart | 20 +++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/packages/flutter_tools/lib/src/android/java.dart b/packages/flutter_tools/lib/src/android/java.dart
index c99c3cf5e79..7a9f3565644 100644
--- a/packages/flutter_tools/lib/src/android/java.dart
+++ b/packages/flutter_tools/lib/src/android/java.dart
@@ -153,6 +153,17 @@ class Java {
     final Iterable<RegExpMatch> matches =
         jdkVersionRegex.allMatches(rawVersionOutput);
     if (matches.isEmpty) {
+      // Fallback to second string format like "java 21.0.1 2023-09-19 LTS"
+      final RegExp secondJdkVersionRegex =
+          RegExp(r'java\s+(?<version>\d+(\.\d+)?(\.\d+)?)\s+\d\d\d\d-\d\d-\d\d');
+      final RegExpMatch? match = secondJdkVersionRegex.firstMatch(versionLines[0]);
+      if (match != null) {
+        final Version? parsedVersion = Version.parse(match.namedGroup('version'));
+        if (parsedVersion == null) {
+          return null;
+        }
+        return parsedVersion;
+      }
       _logger.printWarning(_formatJavaVersionWarning(rawVersionOutput));
       return null;
     }
diff --git a/packages/flutter_tools/test/general.shard/android/java_test.dart b/packages/flutter_tools/test/general.shard/android/java_test.dart
index c7ff6786dae..937f8e05da5 100644
--- a/packages/flutter_tools/test/general.shard/android/java_test.dart
+++ b/packages/flutter_tools/test/general.shard/android/java_test.dart
@@ -280,6 +280,26 @@ OpenJDK 64-Bit Server VM 18.9 (build 11.0.2+9, mixed mode)
         expect(version.toString(), 'openjdk 19.0 2023-01-17');
         expect(version, equals(Version(19, 0, null)));
       });
+
+      testWithoutContext('parses jdk 21 with patch numbers', () {
+        addJavaVersionCommand('''
+java 21.0.1 2023-09-19 LTS
+Java(TM) SE Runtime Environment (build 21+35-LTS-2513)
+Java HotSpot(TM) 64-Bit Server VM (build 21+35-LTS-2513, mixed mode, sharing)
+''');
+        final Version? version = java.version;
+        expect(version, equals(Version(21, 0, 1)));
+      });
+
+      testWithoutContext('parses jdk 21 with no patch numbers', () {
+        addJavaVersionCommand('''
+java 21 2023-09-19 LTS
+Java(TM) SE Runtime Environment (build 21+35-LTS-2513)
+Java HotSpot(TM) 64-Bit Server VM (build 21+35-LTS-2513, mixed mode, sharing)
+''');
+        final Version? version = java.version;
+        expect(version, equals(Version(21, 0, 0)));
+      });
     });
   });
 }