Replace generated javax.annotation.PostConstruct with jakarta (#110)

* Replace generated javax.annotation.PostConstruct with jakarta.annotation.PostConstruct

* Auto detect jakarta vs javax PostConstruct

* Use annotation processing mechanism to discover PostConstruct package

* Add a test for jakarta PostConstruct

---------

Co-authored-by: Jeff Schnitzer <[email protected]>

Author: stickfigure

extensions/src/main/java/org/mapstruct/extensions/spring/converter/ConverterRegistrationConfigurationGenerator.java

@@ -55,10 +55,19 @@ protected TypeSpec createMainTypeSpec(final ConversionServiceAdapterDescriptor d
         .build();
   }
 
-  private static MethodSpec createRegistrationMethodSpec(
+  private ClassName postConstructClassName() {
+    if (isTypeAvailable("jakarta.annotation.PostConstruct")) {
+      return ClassName.get("jakarta.annotation", "PostConstruct");
+    } else {
+      return ClassName.get("javax.annotation", "PostConstruct");
+    }
+  }
+
+  private MethodSpec createRegistrationMethodSpec(
       final FieldSpec convertersFieldSpec, final FieldSpec conversionServiceFieldSpec) {
+
     return MethodSpec.methodBuilder("registerConverters")
-        .addAnnotation(ClassName.get("javax.annotation", "PostConstruct"))
+        .addAnnotation(postConstructClassName())
         .addStatement(
             "$N.forEach($N::addConverter)", convertersFieldSpec, conversionServiceFieldSpec)
         .build();

extensions/src/main/java/org/mapstruct/extensions/spring/converter/Generator.java

@@ -80,7 +80,7 @@ private boolean isSourceVersionAtLeast9() {
     return getProcessingEnvironment().getSourceVersion().compareTo(RELEASE_8) > 0;
   }
 
-  private boolean isTypeAvailable(final String name) {
+  protected boolean isTypeAvailable(final String name) {
     return getProcessingEnvironment().getElementUtils().getTypeElement(name) != null;
   }
 

extensions/src/test/java/org/mapstruct/extensions/spring/converter/ConverterRegistrationConfigurationGeneratorTest.java

@@ -3,20 +3,26 @@
 import static java.lang.Boolean.TRUE;
 import static javax.lang.model.SourceVersion.RELEASE_8;
 import static javax.lang.model.SourceVersion.RELEASE_9;
+import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 import java.io.IOException;
 import java.util.Map;
 import javax.annotation.processing.ProcessingEnvironment;
 import javax.lang.model.SourceVersion;
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.util.Elements;
+
+import org.junit.Rule;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.junit.MockitoRule;
 import org.mockito.junit.jupiter.MockitoExtension;
 import org.mockito.stubbing.Answer;
 
@@ -122,6 +128,24 @@ void shouldGenerateMatchingOutput() throws IOException {
                 underTest::writeGeneratedCodeToOutput);
       }
     }
+
+    @Nested
+    class NoGeneratedJakartaAnnotation {
+      @BeforeEach
+      void initElements() {
+        isAtLeastJava9 = false;
+        when(elements.getTypeElement(anyString()))
+            .thenReturn(null, mock(TypeElement.class)); // first for Generated, second for PostConstruct
+      }
+
+      @Test
+      void shouldGenerateMatchingOutput() throws IOException {
+        ConverterRegistrationConfigurationGeneratorTest.this
+            .shouldGenerateMatchingOutputWhenUsingCustomConversionService(
+                    "ConverterRegistrationConfigurationNoGeneratedJakartaAnnotation.java",
+                    underTest::writeGeneratedCodeToOutput);
+      }
+    }
   }
 
   @Nested

extensions/src/test/resources/ConverterRegistrationConfigurationNoGeneratedJakartaAnnotation.java

@@ -0,0 +1,26 @@
+package org.mapstruct.extensions.spring.converter;
+
+import jakarta.annotation.PostConstruct;
+import java.util.List;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.core.convert.support.ConfigurableConversionService;
+
+@Configuration
+class ConverterRegistrationConfiguration {
+  private final ConfigurableConversionService myConversionService;
+  private final List<Converter<?, ?>> converters;
+
+  ConverterRegistrationConfiguration(
+      @Qualifier("myConversionService") final ConfigurableConversionService myConversionService,
+      final List<Converter<?, ?>> converters) {
+    this.myConversionService = myConversionService;
+    this.converters = converters;
+  }
+  
+  @PostConstruct
+  void registerConverters() {
+    converters.forEach(myConversionService::addConverter);
+  }
+}