The gradle wrapper validator won't work in the machine without internet access

To reproduce it with the latest CI build:

1. Turn off your wifi and keep it without internet access.
2. Clean up ~/tooling/gradle, local gradle user home ~/.gradle, and leave all gradle vscode settings to the default value.
3. Open a sample gradle wrapper project below in VS Code. springbootgradledemo.zip
4. You would be prompted about security warning, and click Trust to continue.
5. Even though the LS status is 👍, but actually it fails to import the gradle project. No .classpath is generated. No projects are displayed in the Java Dependency View.

Both GradleProjectImporter and update project configuration failed with exception. See log.txt for more details.

[fbricon]

Related: https://github.com/eclipse/buildship/pull/998

[testforstephen]

I see, the offline checksum will mitigate the gradle wrapper validator for bad network scenario. But it doesn’t completely solve the offline problem. In fact, gradle wrapper doesn’t really work in OFFLINE, because buildship still needs download the gradle distribution specified by the gradle-wrapper.properties from internet. In OFFLINE mode, only the local gradle home java.import.gradle.home works.

One improvement I can think of at the moment is polishing the description about the gradle user setting.

For example, JLS provides three user settings about specifying a gradle distribution, but the description is not intuitive.

• java.import.gradle.wrapper.enabled - Enable/disable Gradle wrapper. Defaults to true.
• java.import.gradle.version - Gradle version, used if the gradle wrapper is missing or disabled.
• java.import.gradle.home - Setting for GRADLE_HOME

If the user specifies the gradle home via java.import.gradle.home, this setting might not take effect. Because JLS will check the wrapper setting first, and use wrapper distribution if your project contains gradlew script. In order to use the local gradle home, you must disable wrapper and the fixed gradle version settings at the same. The current user setting doesn’t reflect the implicit relationship of these settings.

Another question is about the gradle security, i got new update and will sync up with you offline.