src/java.compiler/share/classes/javax/lang/model/util/Elements.java

@@ -23,13 +23,16 @@
  * questions.
  */
 
 package javax.lang.model.util;
 
-
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
+import java.util.LinkedHashSet;
 
 import javax.lang.model.AnnotatedConstruct;
 import javax.lang.model.element.*;
 
 

@@ -70,10 +73,51 @@
     default PackageElement getPackageElement(ModuleElement module, CharSequence name) {
         return null;
     }
 
     /**
+     * Returns all package elements with the given canonical name.
+     *
+     * There may be more than one package element with the same canonical
+     * name if the package elements are in different modules.
+     *
+     * @implSpec The default implementation of this method calls
+     * {@link #getAllModuleElements() getAllModuleElements} and stores
+     * the result. If the set of modules is empty, {@link
+     * #getPackageElement(CharSequence) getPackageElement(name)} is
+     * called passing through the name argument. If {@code
+     * getPackageElement(name)} is null, an empty set of package
+     * elements is returned; otherwise, a single-element set with the
+     * found package element is returned. If the set of modules is
+     * nonempty, the modules are iterated over and any non-null result
+     * of {@link #getPackageElement(ModuleElement, CharSequence)
+     * getPackageElement(module, name)} are accumulated into a
+     * set. The set is then returned.
+     *
+     * @param name  the canonical name
+     * @return the package elements, or an empty set if no package with the name can be found
+     * @since 9
+     */
+    default Set<? extends PackageElement> getAllPackageElements(CharSequence name) {
+        Set<? extends ModuleElement> modules = getAllModuleElements();
+        if (modules.isEmpty()) {
+            PackageElement packageElt = getPackageElement(name);
+            return (packageElt != null) ?
+                Collections.singleton(packageElt):
+                Collections.emptySet();
+        } else {
+            Set<PackageElement> result = new LinkedHashSet<>(1); // Usually expect at most 1 result
+            for (ModuleElement module: modules) {
+                PackageElement packageElt = getPackageElement(module, name);
+                if (packageElt != null)
+                    result.add(packageElt);
+            }
+            return Collections.unmodifiableSet(result);
+        }
+    }
+
+    /**
      * Returns a type element given its canonical name if the type element is unique in the environment.
      * If running with modules, all modules in the modules graph are searched for matching
      * type elements.
      *
      * @param name  the canonical name

@@ -95,10 +139,51 @@
     default TypeElement getTypeElement(ModuleElement module, CharSequence name) {
         return null;
     }
 
     /**
+     * Returns all type elements with the given canonical name.
+     *
+     * There may be more than one type element with the same canonical
+     * name if the type elements are in different modules.
+     *
+     * @implSpec The default implementation of this method calls
+     * {@link #getAllModuleElements() getAllModuleElements} and stores
+     * the result. If the set of modules is empty, {@link
+     * #getTypeElement(CharSequence) getTypeElement(name)} is called
+     * passing through the name argument. If {@code
+     * getTypeElement(name)} is null, an empty set of type elements is
+     * returned; otherwise, a single-element set with the found type
+     * element is returned. If the set of modules is nonempty, the
+     * modules are iterated over and any non-null result of {@link
+     * #getTypeElement(ModuleElement, CharSequence)
+     * getTypeElement(module, name)} are accumulated into a set. The
+     * set is then returned.
+     *
+     * @param name  the canonical name
+     * @return the type elements, or an empty set if no type with the name can be found
+     * @since 9
+     */
+    default Set<? extends TypeElement> getAllTypeElements(CharSequence name) {
+        Set<? extends ModuleElement> modules = getAllModuleElements();
+        if (modules.isEmpty()) {
+            TypeElement typeElt = getTypeElement(name);
+            return (typeElt != null) ?
+                Collections.singleton(typeElt):
+                Collections.emptySet();
+        } else {
+            Set<TypeElement> result = new LinkedHashSet<>(1); // Usually expect at most 1 result
+            for (ModuleElement module: modules) {
+                TypeElement typeElt = getTypeElement(module, name);
+                if (typeElt != null)
+                    result.add(typeElt);
+            }
+            return Collections.unmodifiableSet(result);
+        }
+    }
+
+    /**
      * Returns a module element given its fully qualified name.
      * If the named module cannot be found, null is returned. One situation where a module
      * cannot be found is if the environment does not include modules, such as
      * an annotation processing environment configured for
      * a {@linkplain

@@ -116,10 +201,30 @@
     default ModuleElement getModuleElement(CharSequence name) {
         return null;
     }
 
     /**
+     * Returns all module elements in the current environment.
+     *
+     * If no modules are present, an empty set is returned. One
+     * situation where no modules are present occurs when the
+     * environment does not include modules, such as an annotation
+     * processing environment configured for a {@linkplain
+     * javax.annotation.processing.ProcessingEnvironment#getSourceVersion
+     * source version} without modules.
+     *
+     * @implSpec The default implementation of this method returns
+     * an empty set.
+     *
+     * @return the known module elements, or an empty set if there are no modules
+     * @since 9
+     */
+    default Set<? extends ModuleElement> getAllModuleElements() {
+        return Collections.emptySet();
+    }
+
+    /**
      * Returns the values of an annotation's elements, including defaults.
      *
      * @see AnnotationMirror#getElementValues()
      * @param a  annotation to examine
      * @return the values of the annotation's elements, including defaults