Android Studio 3.0 Gradle同步报错：无法识别Java版本9.0.4求助

Hey there! Let's work through this issue you're hitting with Android Studio 3.0 and JDK 9.0.4. The core problem here is that Android Studio 3.0 doesn't offer full compatibility with Java 9—it was released before Java 9's widespread adoption, so version detection and Gradle sync break as a result. Below are actionable solutions, ordered by simplicity and reliability:

1. Downgrade to JDK 8 (Recommended) #

JDK 8 is the most stable and fully supported version for Android Studio 3.0. Here's how to make the switch:

• Uninstall JDK 9.0.4 from your Windows 10 system (go to Settings → Apps → Apps & features, find JDK 9.0.4 and select Uninstall).
• Download a compatible JDK 8 release (look for the latest update of JDK 8, e.g., 8u391) from the official Java distribution channel.
• Install JDK 8, then configure your system environment variables:
  • Right-click "This PC" → Properties → Advanced system settings → Environment Variables.
  • Create a new System Variable named JAVA_HOME, set its value to your JDK 8 installation path (e.g., C:\Program Files\Java\jdk1.8.0_391).
  • Edit the Path system variable, add %JAVA_HOME%\bin to the list, and remove any entries pointing to JDK 9.
• Verify the change: Open Command Prompt and run java -version—you should see output showing a 1.8.x version.

2. Force Android Studio to Use JDK 8 (Without Uninstalling JDK 9) #

If you need to keep JDK 9 for other projects, you can tell Android Studio to use JDK 8 exclusively:

• Open Android Studio, go to File → Project Structure → SDK Location.
• In the JDK location section, click the dropdown menu and select your JDK 8 installation path, or manually type it in.
• Click OK, then trigger a Gradle sync by clicking the "Sync Project with Gradle Files" button (the elephant icon in the toolbar).

3. Upgrade Gradle and Plugin (Limited Compatibility with JDK 9) #

If you're set on using JDK 9, you can try upgrading your Gradle setup to a version that has partial support for Java 9. Note that this might not resolve all issues, but it's worth a shot:

• Open your project's root-level build.gradle file.
• Update the Android Gradle Plugin version in the dependencies block to com.android.tools.build:gradle:3.2.1 (this is the latest 3.x plugin with better Java 9 support).
• Open gradle/wrapper/gradle-wrapper.properties and update the distributionUrl to match the compatible Gradle version: https\://services.gradle.org/distributions/gradle-4.6-all.zip.
• Sync your project. If you still run into errors, you'll likely need to fall back to JDK 8.

Additional Troubleshooting Tip #

If Gradle sync still fails after trying the above, clear Android Studio's cache:

• Go to File → Invalidate Caches / Restart.
• Select Invalidate and Restart from the popup—this will clear cached data and restart the IDE, often resolving stubborn sync issues.

内容的提问来源于stack exchange，提问作者NitinNair