public Object getValue(String expression) {
            Object value = valueSource.getValue(expression);

            if (value != null && expression.startsWith(bannedPrefix)) {
                String msg = "The expression ${" + expression + "} is deprecated.";
                if (newPrefix != null && !newPrefix.isEmpty()) {
                    msg += " Please use ${" + newPrefix + expression.substring(bannedPrefix.length()) + "} instead.";

                        "Error evaluating plugin parameter expression: " + expression, e);
            }
        } else if ("reactorProjects".equals(expression)) {
            value = session.getProjects();
        } else if ("project".equals(expression)) {
            value = project;
        } else if ("executedProject".equals(expression)) {
            value = project.getExecutionProject();

    /**
     * Interpolates all expressions in the src parameter.
     * <p>
     * The algorithm used for each expression is:
     * <ul>
     *   <li>If it starts with either "pom." or "project.", the expression is evaluated against the model.</li>
     *   <li>If the value is null, get the value from the context.</li>
     *   <li>If the value is null, but the context contains the expression, don't replace the expression string

import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
import org.codehaus.plexus.component.configurator.expression.TypeAwareExpressionEvaluator;

/**
 * Evaluator for plugin parameters expressions. Content surrounded by <code>${</code> and <code>}</code> is evaluated.
 * Recognized values are:
 * <table border="1">
 * <caption>Expression matrix</caption>

import org.codehaus.plexus.component.configurator.ConfigurationListener;
import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator;
import org.codehaus.plexus.component.repository.ComponentDescriptor;
import org.codehaus.plexus.component.repository.exception.ComponentLifecycleException;

permissions and limitations * under the License. */ import org.apache.maven.plugin.AbstractMojo; /** * Does nothing. * * @goal java * @phase generate-sources * * @author Benjamin Bentmann */ public class AMojo extends AbstractMojo { /** @parameter expression="${version}" default-value="1.0" */ private String version; /** @parameter */ private String[] models; public void execute() { } } src/main/java/org/apache/maven/plugins/coreit/BMojo.java src/main/java/org/apache/maven/plugins/coreit/BMojo.java...

import org.apache.maven.project.MavenProject;
import org.codehaus.plexus.MutablePlexusContainer;
import org.codehaus.plexus.PlexusContainer;
import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator;
import org.codehaus.plexus.configuration.DefaultPlexusConfiguration;
import org.codehaus.plexus.util.Os;
import org.eclipse.aether.DefaultRepositorySystemSession;
import org.eclipse.aether.RepositorySystem;

                    filters.add(new HighestVersionFilter(num));
                } else if ("l".equals(expression)) {
                    filters.add(new LowestVersionFilter());
                } else if (expression.startsWith("l(") && expression.endsWith(")")) {
                    int num = Integer.parseInt(expression.substring(2, expression.length() - 1));

import org.apache.maven.project.MavenProject;
import org.codehaus.plexus.MutablePlexusContainer;
import org.codehaus.plexus.PlexusContainer;
import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator;
import org.codehaus.plexus.configuration.DefaultPlexusConfiguration;
import org.codehaus.plexus.util.Os;
import org.junit.jupiter.api.Test;

          </description>
        </field>
        <field>
          <name>expression</name>
          <version>2.0.0+</version>
          <type>String</type>
          <description>Parameter expression, to let user override default value with a user property, system property or project property.</description>
        </field>
        <field>