Java 类org.reflections.scanners.MethodParameterScanner 实例源码

/**
 * Scans the specified packages for annotated classes, and applies Config values to them.
 * 
 * @param config the Config to derive values from
 * @param packageNamePrefix the prefix to limit scanning to - e.g. "com.github"
 * @return The constructed TypesafeConfigModule.
 */
public static TypesafeConfigModule fromConfigWithPackage(Config config, String packageNamePrefix) {
     ConfigurationBuilder configBuilder = 
         new ConfigurationBuilder()
         .filterInputsBy(new FilterBuilder().includePackage(packageNamePrefix))
         .setUrls(ClasspathHelper.forPackage(packageNamePrefix))
         .setScanners(
            new TypeAnnotationsScanner(), 
            new MethodParameterScanner(), 
            new MethodAnnotationsScanner(), 
            new FieldAnnotationsScanner()
         );
    Reflections reflections = new Reflections(configBuilder);

    return new TypesafeConfigModule(config, reflections);
}

private void init(String packageName) {
  FilterBuilder filters = new FilterBuilder().includePackage(packageName);

  Scanner[] scanners = {
      new TypeAnnotationsScanner(),
      new MethodAnnotationsScanner(),
      new MethodParameterScanner(),
      new FieldAnnotationsScanner(),
      new SubTypesScanner().filterResultsBy(filters)
  };

  reflections = new ConfigurationBuilder()
      .addUrls(ClasspathHelper.forPackage(packageName))
      .addScanners(scanners)
      .filterInputsBy(filters)
      .build();
}

/**
 * Initializes the instance based on what is returned by {@link #ignoreAllAnnotationsAssociatedWithTheseProjectClasses()}
 * and {@link #specificAnnotationDeclarationExclusionsForProject()}. This is time consuming and should only be done
 * once per project if possible - see the usage info in the {@link ReflectionBasedJsr303AnnotationTrollerBase}
 * class-level javadocs.
 *
 * <p>The given set of extra packages for constraint annotation searching will be passed into {@link
 * #getFinalPackagesToSearchForConstraintAnnotations(Set)} to generate the final set of packages that are searched.
 * If you don't want the {@link #DEFAULT_CONSTRAINT_SEARCH_PACKAGES} default packages to be searched you can
 * override {@link #getDefaultPackagesToSearchForConstraintAnnotations()}.
 */
public ReflectionBasedJsr303AnnotationTrollerBase(Set<String> extraPackagesForConstraintAnnotationSearch) {

    /*
     * Set up the {@link #ignoreAllAnnotationsAssociatedWithTheseClasses} and
     * {@link #specificAnnotationDeclarationsExcludedFromStrictMessageRequirement} fields so we know which
     * annotations are project-relevant vs. unit-test-only.
     */
    ignoreAllAnnotationsAssociatedWithTheseClasses =
        new ArrayList<>(setupIgnoreAllAnnotationsAssociatedWithTheseClasses());
    specificAnnotationDeclarationsExcludedFromStrictMessageRequirement =
        new ArrayList<>(setupSpecificAnnotationDeclarationExclusions());

    /*
     * Set up the {@link #reflections}, {@link #constraintAnnotationClasses}, and
     * {@link #allConstraintAnnotationsMasterList} fields. This is where the crazy reflection magic happens to troll
     * the project for the JSR 303 annotation declarations.
     */
    // Create the ConfigurationBuilder to search the relevant set of packages.
    ConfigurationBuilder configurationBuilder = new ConfigurationBuilder();
    for (String packageToAdd : getFinalPackagesToSearchForConstraintAnnotations(
        extraPackagesForConstraintAnnotationSearch)) {
        configurationBuilder.addUrls(ClasspathHelper.forPackage(packageToAdd));
    }

    // Create the Reflections object so it scans for all validation annotations we care about and all project
    //      classes that might have annotations on them.
    reflections = new Reflections(configurationBuilder.setScanners(
        new SubTypesScanner(), new MethodParameterScanner(), new TypeAnnotationsScanner(),
        new MethodAnnotationsScanner(), new FieldAnnotationsScanner()
    ));

    // Gather the list of all JSR 303 validation annotations in the project. Per the JSR 303 spec this is any
    //      annotation class type that is marked with @Constraint.
    constraintAnnotationClasses = new ArrayList<>();
    for (Class<?> constraintAnnotatedType : reflections.getTypesAnnotatedWith(Constraint.class, true)) {
        if (constraintAnnotatedType.isAnnotation()) {
            //noinspection unchecked
            constraintAnnotationClasses.add((Class<? extends Annotation>) constraintAnnotatedType);
        }
    }

    // We're not done gathering validation annotations though, unfortunately. JSR 303 also says that *any*
    //      annotation (whether it is a Constraint or not) that has a value field that returns an array of actual
    //      Constraints is treated as a "multi-value constraint", and the validation processor will run each
    //      of the Constraints in the array as if they were declared separately on the annotated element. Therefore,
    //      we have to dig through all the annotations in the project, find any that fall into this "multi-value
    //      constraint" category, and include them in our calculations.
    for (Class<? extends Annotation> annotationClass : reflections.getSubTypesOf(Annotation.class)) {
        if (isMultiValueConstraintClass(annotationClass))
            constraintAnnotationClasses.add(annotationClass);
    }

    // Setup the master constraint list
    allConstraintAnnotationsMasterList =
        new ArrayList<>(setupAllConstraintAnnotationsMasterList(reflections, constraintAnnotationClasses));

    /*
     * Finally use the info we've gathered/constructed previously to populate the
     * {@link #projectRelevantConstraintAnnotationsExcludingUnitTestsList} field, which is the main chunk of data
     * that extensions of this class will care about.
     */
    projectRelevantConstraintAnnotationsExcludingUnitTestsList = Collections.unmodifiableList(
        getSubAnnotationListUsingExclusionFilters(allConstraintAnnotationsMasterList,
                                                  ignoreAllAnnotationsAssociatedWithTheseClasses,
                                                  specificAnnotationDeclarationsExcludedFromStrictMessageRequirement));
}