Maven插件参数的用户属性是什么意思 [英] What's the meaning of user property of maven plugin parameter

问题描述

我是Maven的新手. 当我尝试引用任何Maven插件文档时，我总是会看到以下格式的参数定义: 名称说明 {参数名称} {说明} 默认值为:... 用户属性是:...

I am a newbie to Maven. When I try to refer to any maven plugin document, I always see following format for the parameter definition: Name Description {parameter name} {description} Default Value is: ... User property is: ...

在大多数情况下，我看到用户属性与参数名称相同. 我想知道用户属性"和参数名称"之间有什么区别.我认为在配置它们时指定相应插件的参数值时，参数名称应为元素标签名称，但是用户属性"的用途是什么?

For most cases, I saw the user property is the same with parameter name. I wonder here what's the difference between "User Property" and "Parameter Name". I think the parameter name should be element tag name when specify the parameter value of the correspond plugin when configure them, but what's the usage of "User Property"?

推荐答案

注意:这是针对Maven 3的.早期版本有所不同.

TL; DR:

用户属性"指定可以使用的 Maven属性的名称设置插件参数.这允许从<configuration>部分之外配置插件.请注意，这仅在<configuration>部分中未指定 的情况下有效(请参见 MNG-4979-无法从命令行覆盖配置参数).

"User property" specifies the name of the Maven property that can be used to set a plugin parameter. This allows configuring a plugin from outside the <configuration> section. Note that this only works if the parameter is not specified in the <configuration> section (see MNG-4979 - Cannot override configuration parameter from command line).

Maven属性可以在POM的<properties>部分中设置，也可以在命令行中设置为-DmyProperty=myValue.

Maven properties can be set in the POM in the section <properties>, or on the command line as -DmyProperty=myValue.

长版

在Maven中，通常在POM的 <configuration>部分中设置插件的参数.插件文档中提供的参数名称"是在配置设置中使用的名称.

In Maven, the parameters of a plugin are usually set in an <configuration> section in the POM. The "parameter name" given in the plugin's documentation is the name to be used in the configuration setting.

例如，Surefire目标 surefire:test 具有参数"failIfNoSpecifiedTests".要将其设置在POM中，请使用:

For example, the Surefire goal surefire:test has a parameter "failIfNoSpecifiedTests". To set it in the POM, use:

<configuration>
<failIfNoSpecifiedTests>false</failIfNoSpecifiedTests>
</configuration>

但是，有时在<configuration>部分之外设置插件参数很有用，例如，在命令行或Maven配置文件中进行设置.为此，插件还可以声明它将从Maven属性(如果已设置)中读取参数值.此属性是文档在 User属性中列出的内容.

However, sometimes it is useful to set a plugin parameter from outside the <configuration> section, for example to set it on the command line, or in a Maven profile. To allow this, a plugin can also declare that it will read the parameter value from a Maven property (if set). This property is what the docs list as the User property.

failIfNoSpecifiedTests的用户属性为surefire.failIfNoSpecifiedTests.因此，也可以使用属性surefire.failIfNoSpecifiedTests代替上面的<configuration>部分.例如:

The User property for failIfNoSpecifiedTests is surefire.failIfNoSpecifiedTests. So instead of the <configuration> section above, one could also use the property surefire.failIfNoSpecifiedTests. For example:

在命令行上
• 通过指定-Dsurefire.failIfNoSpecifiedTests=false
• 在POM配置文件中:<properties> <surefire.failIfNoSpecifiedTests> false </surefire.failIfNoSpecifiedTests> ...

• on the command line, by specifying -Dsurefire.failIfNoSpecifiedTests=false
• in a POM profile: <properties> <surefire.failIfNoSpecifiedTests> false </surefire.failIfNoSpecifiedTests> ...

请注意，插件必须为每个参数声明User属性，因此并非所有参数都具有一个.例如，参数basedir没有用户属性，因此无法在命令行上设置.

Note that the User property must be declared by the plugin for each parameter, so not all parameters will have one. For example, the parameter basedir does not have a User property, so can not be set on the command line.

在插件的源代码中，未明确声明参数名称；它取自Java字段的名称. "failIfNoSpecifiedTests"的源代码为:

In the source code of the plugin, the parameter name not explicitly declared; it is taken from the name of the Java field. The source code for "failIfNoSpecifiedTests" is:

/**
 * Set this to "true" to cause a failure if the none of the tests
 * specified in -Dtest=... are run. Defaults to "true".
 *
 * @since 2.12
 */
@Parameter( property = "surefire.failIfNoSpecifiedTests" )
private Boolean failIfNoSpecifiedTests;

您可以看到参数名称"failIfNoSpecifiedTests"是从字段名称中获取的.注释参数属性"定义了要使用的Maven属性.

You can see that the parameter name "failIfNoSpecifiedTests" is taken from the field name. The annotation parameter "property" defines the Maven property to use.

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