我在IntelliJ上使用spring依赖管理gradle插件。我有一个根模块,其中包含以下内容
apply plugin: "io.spring.dependency-management"
dependencyManagement {
dependencies {
dependencySet(group: "org.apache.hadoop", version: "2.6.0-cdh5.14.4") {
entry "hadoop-common"
entry "hadoop-hdfs"
}
}
}
如果我添加
dependency 'org.apache.hadoop:hadoop-tools:2.6.0-mr1-cdh5.14.4'
或
dependencySet(group: "org.apache.hadoop", version: "2.6.0-mr1-cdh5.14.4") {
entry ("hadoop-tools") {
exclude group: 'ch.qos.logback', module: 'logback-classic'
exclude group: 'org.slf4j', module: 'slf4j-log4j12'
}
}
在根模块中,它不会下载hadoop-tools
jar。仅当我在子模块中添加以下内容时,它才会下载此依赖项。
plugins {
id "com.github.johnrengelman.shadow" version "2.0.4"
}
dependencies {
compile ("org.apache.hadoop:hadoop-tools:2.6.0-mr1-cdh5.14.4") {
exclude group: 'ch.qos.logback', module: 'logback-classic'
exclude group: 'org.slf4j', module: 'slf4j-log4j12'
}
}
为什么会有这种行为?
为了理解这种行为,你需要了解 Spring 依赖管理插件是如何工作的(参见官方文档中的这一部分(:
- 依赖项管理 { }块用于配置将应用于依赖项的约束(要使用的版本、传递依赖项的排除项等(,但此块不会将这些依赖项应用于您的项目,
- 项目的依赖项必须使用依赖项{ }块进行配置
在您的示例中:
-
首先,您在根项目中配置了对"Hadoop-common"和"Hadoop-HDFS"模块的约束的dependencyManagement块,然后在"Hadoop-tools"上添加了contraint(在dependencyManagement块中使用"dependency"或">dependencySet"(:在此阶段,您尚未向项目显式添加任何依赖项,而仅配置了依赖项约束
==> 这就解释了为什么"Hadoop-tools"依赖项没有添加/下载到您的项目中。
-
然后,您使用依赖项块在"Hadoop-tools"上添加了"编译">依赖项,这是声明依赖项的正确方法,这使得"Hadoop-tools"库在您的项目中可用。
如果我很好地理解您的要求,则根据您在问题中提供的源代码:您可以按如下方式配置您的项目:
根项目的脚本
buildscript {
repositories {
jcenter()
}
dependencies {
classpath "org.springframework.boot:spring-boot-gradle-plugin:2.0.4.RELEASE"
}
}
// configure plugins to be applied and dependencies contraints for all subprojects
subprojects {
apply plugin: 'java'
apply plugin: io.spring.gradle.dependencymanagement.DependencyManagementPlugin
dependencyManagement {
dependencies {
// set version for hadoop-common & hadoop-hdfs to "2.6.0-cdh5.14.4"
dependencySet(group: "org.apache.hadoop", version: "2.6.0-cdh5.14.4") {
entry "hadoop-common"
entry "hadoop-hdfs"
}
// set version "2.6.0-mr1-cdh5.14.4" for hadoop-tool,
// and exclude slf4j-log4j12 module from transitive dependencies
dependency (group: "org.apache.hadoop" , name: "hadoop-tools", version : "2.6.0-mr1-cdh5.14.4") {
exclude 'org.slf4j:slf4j-log4j12'
}
}
}
repositories {
jcenter()
maven {
url = 'https://repository.cloudera.com/content/repositories/releases/'
}
}
}
子项目脚本
dependencies{
// hadoop-tools module version is defined (constrained)
// by dependencyManagement in root project build script
compile 'org.apache.hadoop:hadoop-tools'
}