今天想用 Capacitor 編譯 Android 版本的 app，

結果出現如下的錯誤，老實說看不太懂：

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':capacitor-android:compileDebugJavaWithJavac'.
> Could not resolve all files for configuration ':capacitor-android:androidJdkImage'.
> Failed to transform core-for-system-modules.jar to match attributes {artifactType=_internal_android_jdk_image,
org.gradle.libraryelements=jar, org.gradle.usage=java-runtime}.
> Execution failed for JdkImageTransform:
/Users/testuser/Library/Android/sdk/platforms/android-33/core-for-system-modules.jar.
> Error while executing process /Users/testuser/.sdkman/candidates/java/21.0.2-oracle/bin/jlink with arguments
{--module-path
/Users/testuser/.gradle/caches/transforms-3/d20b91a7c402245d65bf0047643c0671/transformed/output/temp/jmod
--add-modules java.base --output
/Users/testuser/.gradle/caches/transforms-3/d20b91a7c402245d65bf0047643c0671/transformed/output/jdkImage
--disable-plugin system-modules}

 

跟 ChatGPT 問了一下，感覺可能是 Android 用到的 Java 沒有支援到 21 那麼新…

上網查了一下，目前 Android 支援的 Java 版本如下，

看起來真的沒有支援到 Java 21…

• Android 14 (API 34) = Java 17
• Android 13 (API 33) = Java 11
• Android 12 (API 32) = Java 11

 

因為我有用 SDKMAN! 來管理不同的 Java 版本，

因此先看一下目前的 Java 版本，果然是 21.0.2：

$ sdk list java

================================================================================
Available Java Versions for macOS ARM 64bit
================================================================================
 Vendor        | Use | Version      | Dist    | Status     | Identifier
--------------------------------------------------------------------------------
 Oracle        |     | 23.0.1       | oracle  |            | 23.0.1-oracle
               |     | 23           | oracle  |            | 23-oracle
               |     | 22.0.2       | oracle  |            | 22.0.2-oracle
               |     | 21.0.5       | oracle  |            | 21.0.5-oracle
               |     | 21.0.4       | oracle  |            | 21.0.4-oracle
               | >>> | 21.0.2       | oracle  | local only | 21.0.2-oracle
               |     | 17.0.12      | oracle  |            | 17.0.12-oracle

 

使用 SDKMAN! 安裝 Oracle Java 17.0.12 版本，

安裝後它問是否要設成預設值 (default)，回答 yes：

sdk install java 17.0.12-oracle

 

這時再重新跑 Capacitor 編譯 Android 程式，看來就沒問題了：

$ npx cap run android

✔ Copying web assets from www to android/app/src/main/assets/public in 142.36ms
✔ Creating capacitor.config.json in android/app/src/main/assets in 10.53ms
[info] Inlining sourcemaps
✔ copy android in 163.82ms
✔ Updating Android plugins in 459.75μs
✔ update android in 27.45ms
✔ Running Gradle build in 70.09s
✔ Deploying app-debug.apk to Pixel_7_Pro_API_35 in 21.00s

 

參考資料：Android 建構作業中的 Java 版本