get mojo parameters in maven plugin

问题

Is there any way to access a plugins properties within the execution method?

I have a base mojo that has some properties, like so:

@Parameter(defaultValue = "DEV", property = "dbEnvironment", required = true)
protected Environment dbEnvironment;

@Parameter(defaultValue = "true", property = "validate")
protected boolean validate;

The child mojo then adds some additional properties. I'd like to be able to read all of these properties, to validate them, but it's not obvious how to do so. When I run it, with debug, I see this:

[DEBUG] Configuring mojo 'com.company.tools:something-maven-plugin:0.2.11-SNAPSHOT:export-job' with basic configurator -->
[DEBUG]   (f) dbEnvironment = DEV
[DEBUG]   (f) jobName = scrape_extract
[DEBUG]   (f) project = MavenProject: com.company.tools:something-maven-plugin-it:1.0-SNAPSHOT @ /Users/selliott/intellij-workspace/tools-something-maven-plugin/something-maven-plugin/src/it/simple-it/pom.xml
[DEBUG]   (f) session = org.apache.maven.execution.MavenSession@3fd2322d
[DEBUG]   (f) validate = true
[DEBUG] -- end configuration --

So, it looks like those props are somewhere, but where? I've tried getting them from the session, session.settings, session.request to no avail.

回答1:

Ok, after much debugging, I was able to figure it out based on how AbstractConfigurationConverter works, specifically the fromExpression method.

To get the properties you need the following added to your mojo:

@Parameter(defaultValue = "${session}")
protected MavenSession session;

@Parameter(defaultValue = "${mojoExecution}")
protected MojoExecution mojoExecution;

From there, you can now create an evaluator and configuration (maybe you can inject them in directly, I'm not sure), and with that you can do this:

    PluginParameterExpressionEvaluator expressionEvaluator = new PluginParameterExpressionEvaluator(session, mojoExecution);
    PlexusConfiguration pomConfiguration = new XmlPlexusConfiguration(mojoExecution.getConfiguration());

    for (PlexusConfiguration plexusConfiguration : pomConfiguration.getChildren()) {
        String value = plexusConfiguration.getValue();
        String defaultValue = plexusConfiguration.getAttribute("default-value");
        try {
            String evaluated = defaultIfNull(expressionEvaluator.evaluate(defaultIfBlank(value, defaultValue)), "").toString();
            System.out.println(plexusConfiguration.getName() + " -> " + defaultIfBlank(evaluated, defaultValue));
        } catch (ExpressionEvaluationException e) {
            e.printStackTrace();
        }
    }

来源：https://stackoverflow.com/questions/50823602/get-mojo-parameters-in-maven-plugin

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java

maven

maven-3