build - Gradle - タスク 'sonarAnalyze' の実行に失敗しました - java.lang.ClassCastException: java.util.ArrayList を java.lang.String にキャストできません

Question

私のgradleビルドスクリプトでソナーを実行すると、このエラーが発生します。

gradle sonarAnalyze

15:41:02.931 [ERROR] [org.gradle.BuildExceptionReporter] FAILURE: Build failed with an   exception.
15:41:02.931 [ERROR] [org.gradle.BuildExceptionReporter]
15:41:02.931 [ERROR] [org.gradle.BuildExceptionReporter] * What went wrong:
15:41:02.931 [ERROR] [org.gradle.BuildExceptionReporter] Execution failed for task  ':sonarAnalyze'.
15:41:02.934 [ERROR] [org.gradle.BuildExceptionReporter] > java.util.ArrayList cannot be cast to java.lang.String



 My sonar 

sonar {
        server { 
        url = "http://server.com:9000"
        }
        database {

            url="jdbc:mysql://server:3306/sonar?useUnicode=true&characterEncoding=utf8"
            driverClassName="com.mysql.jdbc.Driver"
            username="sonar"
            password="sonar"
                }
                project {
                    coberturaReportPath=file("$buildDir/reports/cobertura/coverage.xml")
                    language = "java"
                }

            }

何が問題なのですか？