#214 - ENH: Add support for using @prototype on @factory @bean methods

Author: rbygrave

blackbox-test-inject/src/main/java/org/example/myapp/config/AppConfig.java

@@ -1,7 +1,11 @@
 package org.example.myapp.config;
 
 import io.avaje.inject.Bean;
+import io.avaje.inject.Component;
 import io.avaje.inject.Factory;
+import io.avaje.inject.Prototype;
+import jakarta.inject.Inject;
+import jakarta.inject.Provider;
 import org.example.myapp.HelloData;
 
 @Factory
@@ -20,8 +24,9 @@ public String helloData() {
     }
   }
 
+  @Prototype
   @Bean
-  Builder newBuilder() {
+  public Builder newBuilder() {
     return new Builder();
   }
 
@@ -35,4 +40,19 @@ public static class Builder {
 
   public static class Generated {
   }
+
+  @Component
+  public static class BuilderUser {
+
+    final Provider<Builder> builderProvider;
+
+    @Inject
+    public BuilderUser(Provider<Builder> builderProvider) {
+      this.builderProvider = builderProvider;
+    }
+
+    public Builder createBuilder() {
+      return builderProvider.get();
+    }
+  }
 }

blackbox-test-inject/src/test/java/org/example/myapp/FactoryPrototypeMethodTest.java

@@ -0,0 +1,28 @@
+package org.example.myapp;
+
+import io.avaje.inject.BeanScope;
+import org.example.myapp.config.AppConfig;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class FactoryPrototypeMethodTest {
+
+  @Test
+  void test() {
+    try (BeanScope beanScope = BeanScope.builder().build()) {
+
+      AppConfig.Builder one = beanScope.get(AppConfig.Builder.class);
+      AppConfig.Builder two = beanScope.get(AppConfig.Builder.class);
+      assertThat(one).isNotNull();
+      assertThat(one).isNotSameAs(two);
+
+      AppConfig.BuilderUser builderUser = beanScope.get(AppConfig.BuilderUser.class);
+      AppConfig.Builder b0 = builderUser.createBuilder();
+      AppConfig.Builder b1 = builderUser.createBuilder();
+
+      assertThat(b0).isNotNull();
+      assertThat(b0).isNotSameAs(b1);
+    }
+  }
+}

inject-generator/src/main/java/io/avaje/inject/generator/AllScopes.java

@@ -42,8 +42,9 @@ boolean providedByDefaultModule(String dependency) {
   void readBeans(RoundEnvironment roundEnv) {
     for (Data data : scopeAnnotations.values()) {
       for (Element customBean : roundEnv.getElementsAnnotatedWith(data.type)) {
-        // context.logWarn("read custom scope bean " + customBean + " for scope " + entry.getKey());
-        data.scopeInfo.read((TypeElement) customBean, false);
+        if (customBean instanceof TypeElement) {
+          data.scopeInfo.read((TypeElement) customBean, false);
+        }
       }
     }
   }

inject-generator/src/main/java/io/avaje/inject/generator/MethodReader.java

@@ -17,6 +17,7 @@ class MethodReader {
   private final ExecutableElement element;
   private final String factoryType;
   private final String methodName;
+  private final boolean prototype;
   private final String returnTypeRaw;
   private final GenericType genericType;
   private final String shortName;
@@ -31,11 +32,12 @@ class MethodReader {
   private final boolean optionalType;
 
   MethodReader(ProcessingContext context, ExecutableElement element, TypeElement beanType) {
-    this(context, element, beanType, null, null);
+    this(context, element, beanType, null, null, false);
   }
 
-  MethodReader(ProcessingContext context, ExecutableElement element, TypeElement beanType, Bean bean, Named named) {
+  MethodReader(ProcessingContext context, ExecutableElement element, TypeElement beanType, Bean bean, Named named, boolean prototype) {
     this.isFactory = bean != null;
+    this.prototype = prototype;
     this.element = element;
     this.methodName = element.getSimpleName().toString();
     TypeMirror returnMirror = element.getReturnType();
@@ -129,6 +131,31 @@ String builderBuildBean() {
     return sb.toString();
   }
 
+  public void builderAddProtoBean(Append writer) {
+    if (isVoid) {
+      writer.append("Error - void @Prototype method ?").eol();
+      return;
+    }
+    if (optionalType) {
+      writer.append("Error - Optional type with @Prototype method is not supported").eol();
+      return;
+    }
+    String indent = "    ";
+    writer.append(indent).append("  // prototype scope bean method").eol();
+    writer.append(indent).append("  builder.registerProvider(() -> {").eol();
+    writer.append("%s    return ", indent);
+    writer.append(String.format("factory.%s(", methodName));
+    for (int i = 0; i < params.size(); i++) {
+      if (i > 0) {
+        writer.append(", ");
+      }
+      writer.append(params.get(i).builderGetDependency("builder", true));
+    }
+    writer.append(");").eol();
+    writer.append(indent).append("  });").eol();
+    writer.append(indent).append("}").eol();
+  }
+
   void builderBuildAddBean(Append writer) {
     if (!isVoid) {
       String indent = optionalType ? "        " : "      ";
@@ -228,11 +255,15 @@ public void commentBuildMethod(Append writer) {
     writer.append(CODE_COMMENT_BUILD_FACTORYBEAN, shortName, factoryShortName, methodName).eol();
   }
 
-  public boolean isPublic() {
+  boolean isProtoType() {
+    return prototype;
+  }
+
+  boolean isPublic() {
     return element.getModifiers().contains(Modifier.PUBLIC);
   }
 
-  public boolean isNotPrivate() {
+  boolean isNotPrivate() {
     return !element.getModifiers().contains(Modifier.PRIVATE);
   }
 

inject-generator/src/main/java/io/avaje/inject/generator/Processor.java

@@ -12,9 +12,14 @@
 import javax.annotation.processing.ProcessingEnvironment;
 import javax.annotation.processing.RoundEnvironment;
 import javax.lang.model.SourceVersion;
-import javax.lang.model.element.*;
+import javax.lang.model.element.AnnotationMirror;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.ElementKind;
+import javax.lang.model.element.TypeElement;
 import javax.lang.model.util.Elements;
-import java.util.*;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+import java.util.Set;
 
 public class Processor extends AbstractProcessor {
 
@@ -78,9 +83,10 @@ public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment
   private void readScopes(Set<? extends Element> scopes) {
     for (Element element : scopes) {
       if (element.getKind() == ElementKind.ANNOTATION_TYPE) {
-        // context.logDebug("detected scope annotation " + element);
-        TypeElement type = (TypeElement) element;
-        allScopes.addScopeAnnotation(type);
+        if (element instanceof TypeElement) {
+          TypeElement type = (TypeElement) element;
+          allScopes.addScopeAnnotation(type);
+        }
       }
     }
     addTestScope();
@@ -101,9 +107,8 @@ private void addTestScope() {
    */
   private void readChangedBeans(Set<? extends Element> beans, boolean factory) {
     for (Element element : beans) {
-      if (!(element instanceof TypeElement)) {
-        context.logError("unexpected type [" + element + "]");
-      } else {
+      // ignore methods (e.g. factory methods with @Prototype on them)
+      if (element instanceof TypeElement) {
         TypeElement typeElement = (TypeElement) element;
         final ScopeInfo scope = findScope(typeElement);
         if (!factory) {

inject-generator/src/main/java/io/avaje/inject/generator/SimpleBeanWriter.java

@@ -122,9 +122,13 @@ private void writeFactoryBeanMethod(MethodReader method) {
     writer.append("  public static void build_%s(%s builder) {", method.getName(), beanReader.builderType()).eol();
     method.buildAddFor(writer);
     writer.append(method.builderGetFactory()).eol();
-    writer.append(method.builderBuildBean()).eol();
-    method.builderBuildAddBean(writer);
-    writer.append("    }").eol();
+    if (method.isProtoType()) {
+      method.builderAddProtoBean(writer);
+    } else {
+      writer.append(method.builderBuildBean()).eol();
+      method.builderBuildAddBean(writer);
+      writer.append("    }").eol();
+    }
     writer.append("  }").eol().eol();
   }
 

inject-generator/src/main/java/io/avaje/inject/generator/TypeExtendsInjection.java

@@ -1,6 +1,7 @@
 package io.avaje.inject.generator;
 
 import io.avaje.inject.Bean;
+import io.avaje.inject.Prototype;
 import jakarta.inject.Inject;
 import jakarta.inject.Named;
 
@@ -147,7 +148,8 @@ private void checkForAspect(ExecutableElement methodElement) {
   private void addFactoryMethod(ExecutableElement methodElement, Bean bean) {
     // Not yet reading Qualifier annotations, Named only at this stage
     Named named = methodElement.getAnnotation(Named.class);
-    factoryMethods.add(new MethodReader(context, methodElement, baseType, bean, named).read());
+    boolean prototype = methodElement.getAnnotation(Prototype.class) != null;
+    factoryMethods.add(new MethodReader(context, methodElement, baseType, bean, named, prototype).read());
   }
 
   BeanAspects hasAspects() {

inject/src/main/java/io/avaje/inject/Prototype.java

@@ -1,7 +1,5 @@
 package io.avaje.inject;
 
-import jakarta.inject.Scope;
-
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -21,8 +19,7 @@
  * }
  * }</pre>
  */
-@Target({ElementType.TYPE})
+@Target({ElementType.TYPE, ElementType.METHOD})
 @Retention(RetentionPolicy.RUNTIME)
-@Scope
 public @interface Prototype {
 }