Generates ConversionServiceBridge class.

Chessray · Chessray · commit 77b7cd2b5d0c · 2020-03-30T10:50:07.000+01:00
diff --git a/additions/build.gradle b/additions/build.gradle
@@ -1,5 +1,13 @@
+plugins {
+    id "io.freefair.lombok" version "5.0.0-rc6"
+}
+
 dependencies {
-    // This dependency is used internally, and not exposed to consumers on their own compile classpath.
     implementation 'org.mapstruct:mapstruct:1.3.1.Final'
     implementation 'org.springframework:spring-core:5.0.0.RELEASE'
+    implementation 'com.squareup:javapoet:1.12.1'
+    implementation 'org.apache.commons:commons-lang3:3.10'
+
+    testImplementation 'org.assertj:assertj-core:3.15.0'
+    testImplementation 'commons-io:commons-io:2.6'
 }
diff --git a/additions/lombok.config b/additions/lombok.config
@@ -0,0 +1,2 @@
+# This file is generated by the 'io.freefair.lombok' Gradle plugin
+config.stopBubbling = true
diff --git a/additions/src/main/java/uk/co/kleindelao/mapstruct/spring/converter/ConversionServiceBridgeDescriptor.java b/additions/src/main/java/uk/co/kleindelao/mapstruct/spring/converter/ConversionServiceBridgeDescriptor.java
@@ -0,0 +1,17 @@
+package uk.co.kleindelao.mapstruct.spring.converter;
+
+import com.squareup.javapoet.ClassName;
+import lombok.Builder;
+import lombok.Singular;
+import lombok.Value;
+import org.apache.commons.lang3.tuple.Pair;
+
+import java.util.List;
+
+@Value
+@Builder
+public class ConversionServiceBridgeDescriptor {
+    ClassName bridgeClassName;
+    @Singular
+    List<Pair<ClassName, ClassName>> fromToMappings;
+}
diff --git a/additions/src/main/java/uk/co/kleindelao/mapstruct/spring/converter/ConversionServiceBridgeGenerator.java b/additions/src/main/java/uk/co/kleindelao/mapstruct/spring/converter/ConversionServiceBridgeGenerator.java
@@ -0,0 +1,88 @@
+package uk.co.kleindelao.mapstruct.spring.converter;
+
+import com.squareup.javapoet.*;
+import lombok.Value;
+import org.springframework.core.convert.ConversionService;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.io.Writer;
+import java.time.Clock;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+
+import static java.util.stream.Collectors.toList;
+import static javax.lang.model.element.Modifier.*;
+
+@Value
+public class ConversionServiceBridgeGenerator {
+  Clock clock;
+
+  public void writeConversionServiceBridge(
+      ConversionServiceBridgeDescriptor descriptor, Writer out) {
+    try {
+      JavaFile.builder(
+              descriptor.getBridgeClassName().packageName(),
+              createConversionServiceTypeSpec(descriptor))
+          .build()
+          .writeTo(out);
+    } catch (IOException e) {
+      throw new UncheckedIOException(e);
+    }
+  }
+
+  private TypeSpec createConversionServiceTypeSpec(
+      final ConversionServiceBridgeDescriptor descriptor) {
+    final FieldSpec injectedConversionServiceFieldSpec = buildInjectedConversionServiceFieldSpec();
+    return TypeSpec.classBuilder(descriptor.getBridgeClassName())
+        .addModifiers(PUBLIC)
+        .addAnnotation(buildGeneratedAnnotationSpec())
+        .addAnnotation(ClassName.get("org.springframework.stereotype", "Component"))
+        .addField(injectedConversionServiceFieldSpec)
+        .addMethods(buildMappingMethods(descriptor, injectedConversionServiceFieldSpec))
+        .build();
+  }
+
+  private static Iterable<MethodSpec> buildMappingMethods(
+      final ConversionServiceBridgeDescriptor descriptor,
+      final FieldSpec injectedConversionServiceFieldSpec) {
+    return descriptor.getFromToMappings().stream()
+        .map(
+            sourceTargetPair -> {
+              final ParameterSpec sourceParameterSpec =
+                  buildSourceParameterSpec(sourceTargetPair.getLeft());
+              return MethodSpec.methodBuilder(
+                      "map"
+                          + sourceTargetPair.getLeft().simpleName()
+                          + "To"
+                          + sourceTargetPair.getRight().simpleName())
+                  .addParameter(sourceParameterSpec)
+                  .addModifiers(PUBLIC)
+                  .returns(sourceTargetPair.getRight())
+                  .addStatement(
+                      "return $N.convert($N, $T.class)",
+                      injectedConversionServiceFieldSpec,
+                      sourceParameterSpec,
+                      sourceTargetPair.getRight())
+                  .build();
+            })
+        .collect(toList());
+  }
+
+  private static ParameterSpec buildSourceParameterSpec(final TypeName sourceClassName) {
+    return ParameterSpec.builder(sourceClassName, "source", FINAL).build();
+  }
+
+  private static FieldSpec buildInjectedConversionServiceFieldSpec() {
+    return FieldSpec.builder(ConversionService.class, "conversionService", PRIVATE)
+        .addAnnotation(ClassName.get("org.springframework.beans.factory.annotation", "Autowired"))
+        .build();
+  }
+
+  private AnnotationSpec buildGeneratedAnnotationSpec() {
+    return AnnotationSpec.builder(ClassName.get("javax.annotation", "Generated"))
+        .addMember("value", "$S", ConversionServiceBridgeGenerator.class.getName())
+        .addMember("date", "$S", DateTimeFormatter.ISO_INSTANT.format(ZonedDateTime.now(clock)))
+        .build();
+  }
+}
diff --git a/additions/src/main/java/uk/co/kleindelao/mapstruct/spring/converter/ConverterMapperProcessor.java b/additions/src/main/java/uk/co/kleindelao/mapstruct/spring/converter/ConverterMapperProcessor.java
@@ -1,6 +1,9 @@
-package uk.co.kleindelao.mapstruct.spring;
+package uk.co.kleindelao.mapstruct.spring.converter;
 
+import com.squareup.javapoet.ClassName;
+import org.apache.commons.lang3.tuple.Pair;
 import org.springframework.core.convert.converter.Converter;
+import uk.co.kleindelao.mapstruct.spring.converter.ConversionServiceBridgeDescriptor.ConversionServiceBridgeDescriptorBuilder;
 
 import javax.annotation.processing.AbstractProcessor;
 import javax.annotation.processing.RoundEnvironment;
@@ -11,26 +14,37 @@
 import javax.lang.model.type.DeclaredType;
 import javax.lang.model.type.TypeMirror;
 import javax.lang.model.util.Types;
+import java.io.IOException;
+import java.io.Writer;
+import java.time.Clock;
 import java.util.Optional;
 import java.util.Set;
-import java.util.stream.Collectors;
 
 import static javax.lang.model.element.ElementKind.METHOD;
 import static javax.lang.model.element.Modifier.PUBLIC;
 import static javax.lang.model.type.TypeKind.DECLARED;
-import static javax.tools.Diagnostic.Kind.NOTE;
+import static javax.tools.Diagnostic.Kind.ERROR;
 
 @SupportedAnnotationTypes(ConverterMapperProcessor.ORG_MAPSTRUCT_MAPPER)
 public class ConverterMapperProcessor extends AbstractProcessor {
   protected static final String ORG_MAPSTRUCT_MAPPER = "org.mapstruct.Mapper";
 
+  private final ConversionServiceBridgeGenerator bridgeGenerator =
+      new ConversionServiceBridgeGenerator(Clock.systemUTC());
+
   @Override
   public boolean process(
       final Set<? extends TypeElement> annotations, final RoundEnvironment roundEnv) {
     final Types typeUtils = processingEnv.getTypeUtils();
+    final ConversionServiceBridgeDescriptorBuilder descriptorBuilder =
+        ConversionServiceBridgeDescriptor.builder()
+            .bridgeClassName(
+                ClassName.get(
+                    ConverterMapperProcessor.class.getPackage().getName(),
+                    "ConversionServiceBridge"));
     for (final TypeElement annotation : annotations) {
       if (ORG_MAPSTRUCT_MAPPER.contentEquals(annotation.getQualifiedName())) {
-          roundEnv.getElementsAnnotatedWith(annotation).stream()
+        roundEnv.getElementsAnnotatedWith(annotation).stream()
             .filter(mapper -> mapper.asType().getKind() == DECLARED)
             .filter(mapper -> getConverterSupertype(mapper).isPresent())
             .forEach(
@@ -48,17 +62,31 @@ public boolean process(
                                     getFirstTypeArgument(getConverterSupertype(mapper).get())))
                         .forEach(
                             convert ->
-                                processingEnv
-                                    .getMessager()
-                                    .printMessage(
-                                        NOTE,
-                                        "Found Mapper '"
-                                            + mapper
-                                            + "' with convert method mapping from '"
-                                            + ((ExecutableElement) convert).getParameters().stream().map(Element::asType).map(TypeMirror::toString).collect(Collectors.joining())
-                                            + "' to '"
-                                            + ((ExecutableElement) convert).getReturnType()
-                                            + "'.")));
+                                descriptorBuilder.fromToMapping(
+                                    Pair.of(
+                                        (ClassName)
+                                            ((ExecutableElement) convert)
+                                                .getParameters().stream()
+                                                    .map(Element::asType)
+                                                    .map(ClassName::get)
+                                                    .findFirst()
+                                                    .get(),
+                                        (ClassName)
+                                            ClassName.get(
+                                                ((ExecutableElement) convert).getReturnType())))));
+        try (final Writer outputWriter =
+                     processingEnv
+                             .getFiler()
+                             .createSourceFile(
+                                     ConverterMapperProcessor.class.getPackage().getName() + ".ConversionServiceBridge")
+                             .openWriter()) {
+          bridgeGenerator.writeConversionServiceBridge(descriptorBuilder.build(), outputWriter);
+        } catch (IOException e) {
+          processingEnv
+                  .getMessager()
+                  .printMessage(
+                          ERROR, "Error while opening ConversionServiceBridge output file: " + e.getMessage());
+        }
       }
     }
     return false;
diff --git a/additions/src/main/resources/META-INF/services/javax.annotation.processing.Processor b/additions/src/main/resources/META-INF/services/javax.annotation.processing.Processor
@@ -1 +1 @@
-uk.co.kleindelao.mapstruct.spring.ConverterMapperProcessor
+uk.co.kleindelao.mapstruct.spring.converter.ConverterMapperProcessor
diff --git a/additions/src/test/java/uk/co/kleindelao/mapstruct/spring/converter/ConversionServiceBridgeGeneratorTest.java b/additions/src/test/java/uk/co/kleindelao/mapstruct/spring/converter/ConversionServiceBridgeGeneratorTest.java
@@ -0,0 +1,45 @@
+package uk.co.kleindelao.mapstruct.spring.converter;
+
+import com.squareup.javapoet.ClassName;
+import org.apache.commons.lang3.tuple.Pair;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.time.Clock;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.apache.commons.io.IOUtils.resourceToString;
+import static org.assertj.core.api.BDDAssertions.then;
+
+class ConversionServiceBridgeGeneratorTest {
+  private static final Clock FIXED_CLOCK =
+      Clock.fixed(
+          ZonedDateTime.of(2020, 3, 29, 15, 21, 34, (int) (236 * Math.pow(10, 6)), ZoneId.of("Z")).toInstant(),
+          ZoneId.of("Z"));
+  private final ConversionServiceBridgeGenerator generator =
+      new ConversionServiceBridgeGenerator(FIXED_CLOCK);
+
+  @Test
+  void shouldGenerateMatchingOutput() throws IOException {
+    // Given
+    final ConversionServiceBridgeDescriptor descriptor =
+        ConversionServiceBridgeDescriptor.builder()
+            .bridgeClassName(
+                ClassName.get(
+                    ConversionServiceBridgeGeneratorTest.class.getPackage().getName(),
+                    "ConversionServiceBridge"))
+            .fromToMapping(Pair.of(ClassName.get("test", "Car"), ClassName.get("test", "CarDto")))
+            .build();
+    final StringWriter outputWriter = new StringWriter();
+
+    // When
+    generator.writeConversionServiceBridge(descriptor, outputWriter);
+
+    // Then
+    then(outputWriter.toString())
+        .isEqualToIgnoringWhitespace(resourceToString("/ConversionServiceBridge.java", UTF_8));
+  }
+}
diff --git a/additions/src/test/resources/ConversionServiceBridge.java b/additions/src/test/resources/ConversionServiceBridge.java
@@ -0,0 +1,23 @@
+package uk.co.kleindelao.mapstruct.spring.converter;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.core.convert.ConversionService;
+import org.springframework.stereotype.Component;
+import test.Car;
+import test.CarDto;
+
+import javax.annotation.Generated;
+
+@Generated(
+        value = "uk.co.kleindelao.mapstruct.spring.converter.ConversionServiceBridgeGenerator",
+        date = "2020-03-29T15:21:34.236Z"
+)
+@Component
+public class ConversionServiceBridge {
+    @Autowired
+    private ConversionService conversionService;
+
+    public CarDto mapCarToCarDto(final Car source) {
+        return conversionService.convert(source, CarDto.class);
+    }
+}
diff --git a/tests/build.gradle b/tests/build.gradle
@@ -1,12 +1,23 @@
 plugins {
-    id "io.freefair.lombok" version "5.0.0-rc6"
+    id 'io.freefair.lombok' version '5.0.0-rc6'
+    id 'org.assertj.generator' version '0.0.6b'
 }
 
 dependencies {
     annotationProcessor project(":additions")
     // This dependency is used internally, and not exposed to consumers on their own compile classpath.
+    compileOnly 'javax.annotation:jsr250-api:1.0'
     implementation 'org.mapstruct:mapstruct:1.3.1.Final'
     annotationProcessor 'org.mapstruct:mapstruct-processor:1.3.1.Final'
     implementation 'org.springframework:spring-core:5.0.0.RELEASE'
     implementation 'org.springframework:spring-context:5.0.0.RELEASE'
+    testImplementation 'org.springframework:spring-test:5.0.0.RELEASE'
+    testImplementation 'org.assertj:assertj-core:3.15.0'
 }
+
+sourceSets {
+    main {
+        // must specify assertJ block to have it applied
+        assertJ {}
+    }
+}
diff --git a/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/Car.java b/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/Car.java
@@ -1,10 +1,12 @@
 package uk.co.kleindelao.mapstruct.spring.example;
 
 import lombok.Data;
+import lombok.experimental.Accessors;
 
 @Data
+@Accessors(chain = true)
 public class Car {
     private String make;
-    private int numberOfSeats;
+    private SeatConfiguration seatConfiguration;
     private CarType type;
 }
diff --git a/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/CarDto.java b/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/CarDto.java
@@ -5,6 +5,6 @@
 @Data
 public class CarDto {
     private String make;
-    private int seatCount;
+    private SeatConfigurationDto seats;
     private String type;
 }
diff --git a/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/CarMapper.java b/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/CarMapper.java
@@ -6,6 +6,6 @@
 
 @Mapper(config = MapperSpringConfig.class)
 public interface CarMapper extends Converter<Car, CarDto> {
-    @Mapping(source = "numberOfSeats", target = "seatCount")
+    @Mapping(target = "seats", source = "seatConfiguration")
     CarDto convert(Car car);
 }
diff --git a/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/MapperSpringConfig.java b/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/MapperSpringConfig.java
@@ -1,7 +1,10 @@
 package uk.co.kleindelao.mapstruct.spring.example;
 
 import org.mapstruct.MapperConfig;
+import uk.co.kleindelao.mapstruct.spring.converter.ConversionServiceBridge;
 
-@MapperConfig(componentModel = "spring")
+import static org.mapstruct.ReportingPolicy.ERROR;
+
+@MapperConfig(componentModel = "spring", uses = ConversionServiceBridge.class, unmappedTargetPolicy = ERROR)
 public interface MapperSpringConfig {
 }
diff --git a/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/SeatConfiguration.java b/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/SeatConfiguration.java
@@ -0,0 +1,11 @@
+package uk.co.kleindelao.mapstruct.spring.example;
+
+import lombok.Data;
+import lombok.experimental.Accessors;
+
+@Data
+@Accessors(chain = true)
+public class SeatConfiguration {
+    private int numberOfSeats;
+    private SeatMaterial seatMaterial;
+}
diff --git a/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/SeatConfigurationDto.java b/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/SeatConfigurationDto.java
@@ -0,0 +1,9 @@
+package uk.co.kleindelao.mapstruct.spring.example;
+
+import lombok.Data;
+
+@Data
+public class SeatConfigurationDto {
+    private int seatCount;
+    private String material;
+}
diff --git a/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/SeatConfigurationMapper.java b/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/SeatConfigurationMapper.java
@@ -0,0 +1,12 @@
+package uk.co.kleindelao.mapstruct.spring.example;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.springframework.core.convert.converter.Converter;
+
+@Mapper(config = MapperSpringConfig.class)
+public interface SeatConfigurationMapper extends Converter<SeatConfiguration, SeatConfigurationDto> {
+    @Mapping(target = "seatCount", source = "numberOfSeats")
+    @Mapping(target = "material", source = "seatMaterial")
+    SeatConfigurationDto convert(SeatConfiguration seatConfiguration);
+}
diff --git a/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/SeatMaterial.java b/tests/src/main/java/uk/co/kleindelao/mapstruct/spring/example/SeatMaterial.java
diff --git a/tests/src/test/java/uk/co/kleindelao/mapstruct/spring/example/ConversionServiceBridgeIntegrationTest.java b/tests/src/test/java/uk/co/kleindelao/mapstruct/spring/example/ConversionServiceBridgeIntegrationTest.java

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+# This file is generated by the 'io.freefair.lombok' Gradle plugin`
	`2`	`+config.stopBubbling = true`
Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-uk.co.kleindelao.mapstruct.spring.ConverterMapperProcessor`
	`1`	`+uk.co.kleindelao.mapstruct.spring.converter.ConverterMapperProcessor`