在exec-maven-plugin中设置systemProperty不起作用 [英] set systemProperty in exec-maven-plugin does not work

问题描述

这是我的pom.xml文件:

Here is my pom.xml file:

<project>
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.test</groupId>
    <artifactId>test</artifactId>
    <version>1.0-SNAPSHOT</version>

    <profiles>
        <profile>
            <id>my_proj</id>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.codehaus.mojo</groupId>
                        <artifactId>exec-maven-plugin</artifactId>
                        <version>1.4.0</version>
                        <executions>
                            <execution>
                                <phase>install</phase>
                                <goals>
                                    <goal>exec</goal>
                                </goals>
                            </execution>
                        </executions>
                        <configuration>

                            <executable>java</executable>
                            <arguments>
                                <argument>-classpath</argument>
                                <classpath />
                                <argument>com.test.Main</argument>

                            </arguments>
                            <systemProperties>
                                <systemProperty>
                                    <key>someKey</key>
                                    <value>someValue</value>
                                </systemProperty>
                            </systemProperties>
                            <environmentVariables>
                                <someKey>
                                    someValue
                                </someKey>
                            </environmentVariables>
                        </configuration>
                    </plugin>
                </plugins>
            </build>

        </profile>
    </profiles>

</project>

和Main.java

and in Main.java

public static void main(String[] args) {

    System.out.println("hello world" + System.getenv("someKey") + " " + System.getProperty("someKey"));
}

我运行时的输出

mvn install -Pmy_proj

是

hello worldsomeValue null

我似乎无法获得systemProperty值.我做错了什么?

I cannot seem to get the systemProperty value. What did I do wrong ?

推荐答案

systemProperty不能仅仅因为它不是 exec-maven-plugin .

The systemProperty does not work simply because it is not an expected element of the exec goal of the exec-maven-plugin.

检查正式的 exec目标页面，否指定了systemProperties元素.这样，您的配置仍然对Maven仍然有效，只是因为它是格式正确的XML，但exec-maven-plugin会忽略它.

Check the official exec goal page, no systemProperties element is specified. As such, your configuration is still valid for Maven simply because is well-formed XML, but it is ignored by the exec-maven-plugin.

有关插件configuration元素的官方 Maven Pom参考:

可能需要注意的是，所有配置元素，无论它们位于POM内的什么地方，都旨在将值传递给另一个基础系统，例如插件.换句话说:POM模式从不明确要求配置元素中的值，但是插件目标具有要求配置值的所有权利.

It may be good to note that all configuration elements, wherever they are within the POM, are intended to pass values to another underlying system, such as a plugin. In other words: values within a configuration element are never explicitly required by the POM schema, but a plugin goal has every right to require configuration values.

---

您对 systemProperties 通过其 java 目标预见的配置条目.此选项因其上下文而在此处可用:它是为Java执行而设计的.另一方面，exec目标更加通用，因此无法预见仅Java程序需要的选项.

---

You are making confusion with the systemProperties configuration entry foreseen by its java goal. This option is available there because of its context: it's crafted for java executions. On the other hand, the exec goal is much more generic and as such cannot foresee an option required only by java programs.

要通过exec目标将系统属性传递给Java执行，可以使用 arguments 配置条目，并使用 -D表示法

To pass system properties to a Java execution via the exec goal, you can use the arguments configuration entry and use the -D notation

-Dproperty=value设置系统属性值.

-Dproperty=value Sets a system property value.

根据官方使用exec目标文档运行Java程序，应首先使用-D参数:

Further note, as per official Running Java programs with the exec goal documentation, the -D arguments should go first:

<configuration>
    <executable>java</executable>
    <arguments>
        <argument>-DsomeKey2=someValue2</argument>
        <argument>-classpath</argument>
        <classpath />
        <argument>com.test.Main</argument>
    </arguments>
    <environmentVariables>
        <someKey>someValue</someKey>
    </environmentVariables>
</configuration>

此外，您不应为环境设置相同的变量名，并且作为系统属性，否则将不会设置系统属性.

Moreover, you should not set the same variable name for environment and as system property, the system property would not be set otherwise.

这篇关于在exec-maven-plugin中设置systemProperty不起作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！