GH-392 Add example for the DI Wiki post

panda-utilities/src/main/java/org/panda_lang/utilities/annotations/adapter/JavassistAdapter.java

@@ -38,13 +38,15 @@
 import java.util.Arrays;
 import java.util.List;
 
+
+
 public final class JavassistAdapter implements MetadataAdapter<ClassFile, FieldInfo, MethodInfo> {
 
     public static final boolean includeInvisibleTag = true;
 
     @Override
     public boolean acceptsInput(String file) {
-        return file.endsWith(".class");
+        return file.endsWith(".class") && !file.contains("module-info.class");
     }
 
     private List<String> splitDescriptorToTypeNames(String descriptors) {
@@ -171,21 +173,16 @@ public String getFieldName(FieldInfo field) {
     }
 
     @Override
-    public @Nullable ClassFile getOfCreateClassObject(AnnotationsScanner scanner, AnnotationsScannerFile file) {
+    public ClassFile getOfCreateClassObject(AnnotationsScanner scanner, AnnotationsScannerFile file) throws Exception {
         InputStream inputStream = null;
 
         try {
             inputStream = file.openInputStream();
             DataInputStream dis = new DataInputStream(new BufferedInputStream(inputStream));
             return new ClassFile(dis);
-        } catch (Exception e) {
-            scanner.getLogger().exception(e);
-            scanner.getLogger().error("Could not create class file from " + file.getInternalPath());
         } finally {
             IOUtils.close(inputStream);
         }
-
-        return null;
     }
 
     @Override

panda-utilities/src/main/java/org/panda_lang/utilities/annotations/adapter/MetadataAdapter.java

@@ -53,7 +53,7 @@ public interface MetadataAdapter<C, F, M> {
 
     String getFieldName(F field);
 
-    C getOfCreateClassObject(AnnotationsScanner scanner, AnnotationsScannerFile file);
+    C getOfCreateClassObject(AnnotationsScanner scanner, AnnotationsScannerFile file) throws Exception;
 
     String getMethodModifier(M method);
 

panda-utilities/src/main/java/org/panda_lang/utilities/inject/InjectorAnnotation.java

@@ -22,6 +22,12 @@
 import java.util.HashMap;
 import java.util.Map;
 
+/**
+ * Annotation data wrapper.
+ * Stores data about the annotation in {@link org.panda_lang.utilities.inject.InjectorAnnotation.Metadata} container.
+ *
+ * @param <T> annotation type
+ */
 public final class InjectorAnnotation<T extends Annotation> {
 
     private final T annotation;
@@ -53,6 +59,11 @@ public T getAnnotation() {
         return annotation;
     }
 
+    /**
+     * Stores in key-value format data about the associated annotation
+     *
+     * @param <T>
+     */
     public static final class Metadata<T extends Annotation> {
 
         private final Class<? extends Annotation> annotationType;

panda-utilities/src/main/java/org/panda_lang/utilities/inject/InjectorResources.java

@@ -35,16 +35,16 @@ public interface InjectorResources {
      *
      * @param annotation the annotation to bind
      * @param <T> type of annotation
-     * @return the bind based on associate annotation
+     * @return the bind based on associated annotation
      */
     <T extends Annotation> InjectorResourceBind<T, T> annotatedWith(Class<T> annotation);
 
     /**
-     * Create bind for parameters annotated with the specified annotation with no
+     * Create bind for parameters annotated with the specified annotation converted into to {@link org.panda_lang.utilities.inject.InjectorAnnotation}
      *
      * @param annotation the annotation to bind
      * @param <T> type of annotation
-     * @return the bind based on associate annotation
+     * @return the bind based on associated annotation
      */
     <T extends Annotation> InjectorResourceBind<T, InjectorAnnotation<T>> annotatedWithMetadata(Class<T> annotation);
 

panda-utilities/src/test/java/org/panda_lang/utilities/inject/DependencyInjectionWikiTest.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2015-2020 Dzikoysk
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.panda_lang.utilities.inject;
+
+import org.junit.jupiter.api.Test;
+import org.panda_lang.utilities.inject.annotations.Inject;
+import org.panda_lang.utilities.inject.annotations.Injectable;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.util.UUID;
+
+final class DependencyInjectionWikiTest {
+
+    @Test
+    void testWikiExample() throws Exception {
+        Injector injector = DependencyInjection.createInjector(resources -> {
+            resources.annotatedWith(AwesomeRandom.class).assignHandler((expectedType, annotation) -> {
+                if (expectedType.equals(String.class)) {
+                    return UUID.randomUUID().toString();
+                }
+
+                if (expectedType.equals(UUID.class)) {
+                    return UUID.randomUUID();
+                }
+
+                throw new IllegalArgumentException("Unsupported type " + expectedType);
+            });
+        });
+
+        Entity entityA = injector.newInstance(Entity.class);
+        Entity entityB = injector.newInstance(Entity.class);
+
+        System.out.println(entityA.getId());
+        System.out.println(entityB.getId());
+    }
+
+    @Injectable // mark annotation as DI ready annotation
+    @Retention(RetentionPolicy.RUNTIME) // make sure that the annotation is visible at runtime
+    @interface AwesomeRandom { }
+
+    private static final class Entity {
+        private final UUID id;
+
+        @Inject //it's not required, but it might be useful to disable "unused method" warnings/scanning for annotations
+        private Entity(@AwesomeRandom UUID random) {
+            this.id = random;
+        }
+
+        public UUID getId() {
+            return id;
+        }
+    }
+
+}