liquibase gradle插件找不到org.postgresql.Driver

Question

我正在尝试使用liquibase-gradle-plugin在数据库和Springboot实体之间生成数据库差异。但是，我总是得到错误说

  

liquibase.exception.LiquibaseException：运行Liquibase时出现意外错误：java.lang.RuntimeException：找不到数据库驱动程序：class org.postgresql.Driver

我根据一些谷歌搜索结果将类路径依赖项放在buildscripts块中。但它没有帮助。下面是我的build.gradle

buildscript {
    ext {
        springBootVersion = '1.5.6.RELEASE'
    }
    repositories {
        mavenCentral()
        maven { url "https://repo.spring.io/milestone" }
        maven {
            url "https://plugins.gradle.org/m2/"
          }
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
        classpath('org.postgresql:postgresql:9.4.1212')
    }
}

//When the liquibase plugin is applied, it creates a Gradle task for each command supported by Liquibase.
plugins {
    id 'org.liquibase.gradle' version '1.2.4'
}

apply from: 'liquibase.gradle'

liquibase {
    activities {
      diffMain {
        url gradle.ext.url
        username gradle.ext.username
        password gradle.ext.password
        referenceUrl gradle.ext.referenceUrl
        driver org.postgresql.Driver
      }
    }
    runList = 'diffMain'
}