klerb
klerb

Reputation: 21

How to chain multiple properties in an expression using maven help:evaluate?

Context:

I am trying to chain multiple maven properties (connected with a '-') in the same expression to be outputted to the command line using a single line command (this will be a command to be executed in a Jenkins pipeline). I believe I should be able to do achieve this using the maven-help-plugin. For example, if I run the following command:mvn help:evaluate

Then when prompted I interactively supply the multi-property expression: ${project.artifactId}-${project.version}

I get back the expected value: maven-tests-0.0.3-SNAPSHOT

The Goal:

I want to be able to use the plugin non-interactively by supplying the expression using the -Dexpression flag. As specified in the documentation for the maven-help-plugin, properties in the expression should not be wrapped by ${}, so I used the following command:
mvn help:evaluate -Dexpression=project.artifactId-project.version -q -DforceStdout

In return I get a null object or invalid expression error.

It may be that the plugin completely disallows multiple properties in one expression using this method, but I could not find anything that seemed to suggest this.

What I've tried:

Pom.xml

The version of the maven-help-plugin used is 3.2.0, managed from spring-boot-starter-parent.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.1.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.x.y</groupId>
    <artifactId>maven-tests</artifactId>
    <version>0.0.3-SNAPSHOT</version>
    <name>maven-tests</name>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-release-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-help-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>versions-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>build-helper-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <id>parse-version</id>
                        <goals>
                            <goal>parse-version</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

Upvotes: 2

Views: 136

Answers (0)

Related Questions