*/
    @Nonnull
    String defaultValue() default "";

    /**
     * is the parameter required?
     * @return <code>true</code> if the Mojo should fail when the parameter cannot be injected
     */
    boolean required() default false;

    /**
     * Specifies that this parameter cannot be configured directly by the user (as in the case of POM-specified

        DEPRECATED_CORE_PARAMETERS = deprecatedCoreParameters;
    }

    @Inject
    DeprecatedCoreExpressionValidator(PluginValidationManager pluginValidationManager) {
        super(pluginValidationManager);
    }

    @Override
    protected String getParameterLogReason(Parameter parameter) {
        return "uses deprecated parameter expression '" + parameter.getDefaultValue() + "': "

            mojoDescriptor.getParameters().stream()
                    .filter(parameter -> parameter.getDeprecated() != null)
                    .filter(Parameter::isEditable)
                    .forEach(parameter -> checkParameter(
                            mavenSession, mojoDescriptor, mojoClass, parameter, pomConfiguration, expressionEvaluator));
        }
    }

    private void checkParameter(

    protected abstract String getParameterLogReason(Parameter parameter);

    protected String formatParameter(Parameter parameter) {
        StringBuilder stringBuilder = new StringBuilder()
                .append("Parameter '")
                .append(parameter.getName())
                .append('\'');

        if (parameter.getExpression() != null) {

    }

    private Stream<String> getParameterNames(Parameter parameter) {
        if (parameter.getAlias() != null) {
            return Stream.of(parameter.getName(), parameter.getAlias());
        } else {
            return Stream.of(parameter.getName());
        }
    }

    private Set<String> getUnknownParameters(MojoExecution mojoExecution, Set<String> parameters) {

            if (properties != null) {
                // We will attempt to get nab a property as a way to specify a parameter
                // to a plugin. My particular case here is allowing the surefire plugin
                // to run a single test so I want to specify that class on the cli as
                // a parameter.

                value = properties.getProperty(expression);
            }

    private final Map<String, Parameter> missingParameters;

    ValidatingConfigurationListener(Object mojo, MojoDescriptor mojoDescriptor, ConfigurationListener delegate) {
        this.mojo = mojo;
        this.delegate = delegate;
        this.missingParameters = new HashMap<>();

        if (mojoDescriptor.getParameters() != null) {
            for (Parameter param : mojoDescriptor.getParameters()) {

        </field>
      </fields>
    </class>

    <class xdoc.anchorName="parameter">
      <name>Parameter</name>
      <version>1.0.0+</version>
      <description>A phase mapping definition.</description>
      <!-- see o.a.m.plugin.descriptor.Parameter -->
      <fields>
        <field>
          <name>name</name>
          <version>1.0.0+</version>

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 package org.apache.maven.plugin.coreit;...

            return;
        }

        List<Parameter> invalidParameters = new ArrayList<>();

        for (Parameter parameter : mojoDescriptor.getParameters()) {
            if (!parameter.isRequired()) {
                continue;
            }

            Object value = null;

            PlexusConfiguration config = configuration.getChild(parameter.getName(), false);
            if (config != null) {