Why Java‑Groovy Builds Fail on Jenkins and How to Fix Them

When mixing Java and Groovy code, the author found that cross‑calls worked on the local machine but caused a "cannot find symbol" compilation error on Jenkins and when executing Gradle tasks.

错误: 找不到符号
import com.fission.alpha.base.Util;

After consulting a colleague, the solution was to rename the problematic file with a .groovy extension and to apply the Groovy compilation plugin in build.gradle. This forces Gradle to compile Groovy sources first, after which Java sources can reference the generated classes without errors.

After the change, the project’s directory layout looks like the following (illustrated in the image):

The updated build.gradle includes the necessary plugins:

apply plugin: 'java'
apply plugin: 'idea'
apply plugin: 'groovy'

With these adjustments, the build succeeds both locally and on Jenkins, eliminating the symbol‑not‑found error.