无法获取类型为org.gradle.api.internal.initialization.DefaultScriptHandler的对象的未知属性

Question

执行gradle构建时遇到错误-

无法获取类型为org.gradle.api.internal.initialization.DefaultScriptHandler的对象的未知属性'maven_url'。

def checkUserProperty(String propertyName) {
  if (!project.hasProperty(propertyName)) {
    throw new GradleException('Property "' + propertyName + '" not defined, this should be defined in your "<USER_HOME>/.gradle/gradle.properties" file or on the command line using the -P flag.')
  }
}

checkUserProperty('maven_url')

ext.set('quantexa_explorer_releases', maven_url + "/quantexa-explorer-releases/")
ext.set('quantexa_explorer_snapshots', maven_url + "/quantexa-explorer-snapshots/")
ext.set('quantexa_accelerators_releases', maven_url + "/quantexa-accelerators-releases/")
ext.set('quantexa_accelerators_snapshots', maven_url + "/quantexa-accelerators-snapshots/")

def isDevMode() {
  return project.hasProperty('dev') && project.getProperty('dev') == 'true'
}

if (isDevMode()) {
  println "Development profile active, project jars will not be packed into containers"
}

buildscript {
  ext {
    if (gradle.startParameter.gradleHomeDir.getPath().contains("wrapper")) {
      print('Gradle wrapper version: ')
    } else {
      print('Gradle version: ')
    }
    println(gradle.gradleVersion)
    // Our custom gradle task (below) takes its version from gradle.properties
    propertiesGradleVersion = gradleVersion

    springBootVersion = '1.5.20.RELEASE'
    moowork = '1.2.0'
    gradleCredentials = '1.0.4'
    gradleRelease = '2.8.0'
    docker = '0.21.0'
    nexusPlugin = '2.3.1'
    quantexaPluginsVersion = "0.7.1"
    scalaTestPlugin = '0.23'
    gitInfoPlugin = "2.0.0"
  }
  ext.set('quantexa_gradle_plugins_releases', maven_url + "/quantexa-gradle-plugins-releases/")
  ext.set('quantexa_gradle_plugins_snapshots', maven_url + "/quantexa-gradle-plugins-snapshots/")
  ext.set('quantexa_releases', maven_url + "/quantexa-releases/")
````````````````````

Below is my gradle.properties file looks like -

maven_user = admin

maven_url = http://localhost:19201/nexus/content/repositories