Allow generation a report class

Author: reda-alaoui

api/src/main/java/com/cosium/json_schema_to_java_record_api/GenerateRecordsFromJsonSchemas.java

@@ -12,4 +12,9 @@
   JsonSchemaFileLocation[] schemaRootFileLocations();
 
   JsonSchemaConfiguration[] schemaConfigurations() default {};
+
+  /**
+   * @return A non-empty string to generate a report class. Empty otherwise.
+   */
+  String reportClassQualifiedName() default "";
 }

core/src/main/java/com/cosium/json_schema_to_java_record/AnnotationProcessor.java

@@ -7,6 +7,7 @@
 import java.util.concurrent.CopyOnWriteArraySet;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
+import javax.annotation.processing.Filer;
 import javax.annotation.processing.ProcessingEnvironment;
 import javax.annotation.processing.Processor;
 import javax.annotation.processing.RoundEnvironment;
@@ -28,13 +29,13 @@ public class AnnotationProcessor extends AbstractLoggingProcessor {
 
   private final Set<Command> processedCommands = new CopyOnWriteArraySet<>();
 
-  @Nullable private JavaTypes javaTypes;
+  @Nullable private Filer filer;
   @Nullable private JsonSchemas jsonSchemas;
 
   @Override
   public synchronized void init(ProcessingEnvironment processingEnv) {
     super.init(processingEnv);
-    this.javaTypes = new JavaTypes(processingEnv.getFiler());
+    this.filer = processingEnv.getFiler();
     jsonSchemas = new JsonSchemas(new ReadonlyClassPathResources(processingEnv.getFiler()));
   }
 
@@ -55,7 +56,7 @@ protected boolean doProcess(Set<? extends TypeElement> annotations, RoundEnviron
 
     commands.stream()
         .peek(command -> LOGGER.debug("Executing {}", command))
-        .forEach(command -> command.execute(javaTypes, jsonSchemas));
+        .forEach(command -> command.execute(filer, jsonSchemas));
 
     processedCommands.addAll(commands);
 

core/src/main/java/com/cosium/json_schema_to_java_record/Command.java

@@ -4,6 +4,7 @@
 
 import com.cosium.json_schema_to_java_record_api.GenerateRecordsFromJsonSchemas;
 import java.util.Arrays;
+import javax.annotation.processing.Filer;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.PackageElement;
 
@@ -17,12 +18,14 @@ record Command(Element annotatedElement, GenerateRecordsFromJsonSchemas annotati
     requireNonNull(annotation);
   }
 
-  public void execute(JavaTypes javaTypes, JsonSchemas jsonSchemas) {
+  public void execute(Filer filer, JsonSchemas jsonSchemas) {
     Configuration configuration = new Configuration(annotatedElementPackageName(), annotation);
 
-    Arrays.stream(annotation.schemaRootFileLocations())
-        .map(jsonSchemas::parse)
-        .forEach(jsonSchema -> jsonSchema.writeJavaType(javaTypes, configuration));
+    try (JavaTypes javaTypes = new JavaTypes(filer, annotation)) {
+      Arrays.stream(annotation.schemaRootFileLocations())
+          .map(jsonSchemas::parse)
+          .forEach(jsonSchema -> jsonSchema.writeJavaType(javaTypes, configuration));
+    }
   }
 
   private String annotatedElementPackageName() {

core/src/main/java/com/cosium/json_schema_to_java_record/JavaTypes.java

@@ -5,28 +5,45 @@
 import com.cosium.json_schema_to_java_record_api.GenerateRecordsFromJsonSchemas;
 import com.palantir.javapoet.AnnotationSpec;
 import com.palantir.javapoet.ClassName;
+import com.palantir.javapoet.CodeBlock;
+import com.palantir.javapoet.FieldSpec;
 import com.palantir.javapoet.JavaFile;
+import com.palantir.javapoet.MethodSpec;
+import com.palantir.javapoet.ParameterizedTypeName;
 import com.palantir.javapoet.TypeSpec;
 import java.io.IOException;
 import java.io.UncheckedIOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.function.Predicate;
 import javax.annotation.processing.Filer;
 import javax.annotation.processing.FilerException;
 import javax.annotation.processing.Generated;
+import javax.lang.model.element.Modifier;
 import javax.tools.StandardLocation;
+import org.jspecify.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
  * @author Réda Housni Alaoui
  */
-class JavaTypes {
+class JavaTypes implements AutoCloseable {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(JavaTypes.class);
 
   private final Filer filer;
+  @Nullable private final ClassName reportClassName;
+  private final Map<String, ClassName> classNameBySchemaId = new HashMap<>();
 
-  JavaTypes(Filer filer) {
+  JavaTypes(Filer filer, GenerateRecordsFromJsonSchemas annotation) {
     this.filer = requireNonNull(filer);
+    reportClassName =
+        Optional.of(annotation.reportClassQualifiedName())
+            .filter(Predicate.not(String::isBlank))
+            .map(ClassName::bestGuess)
+            .orElse(null);
   }
 
   public boolean existsOnClassPath(ClassName className) {
@@ -39,12 +56,16 @@ public boolean existsOnClassPath(ClassName className) {
     }
   }
 
-  public void write(String packageName, TypeSpec.Builder typeSpecBuilder) {
-    typeSpecBuilder.addAnnotation(
-        AnnotationSpec.builder(Generated.class)
-            .addMember("value", "$S", GenerateRecordsFromJsonSchemas.class.getName())
-            .build());
-    write(JavaFile.builder(packageName, typeSpecBuilder.build()).build());
+  public void write(
+      @Nullable String schemaId, String packageName, TypeSpec.Builder typeSpecBuilder) {
+
+    TypeSpec typeSpec = markAsGenerated(typeSpecBuilder).build();
+
+    if (schemaId != null) {
+      classNameBySchemaId.put(schemaId, ClassName.get(packageName, typeSpec.name()));
+    }
+
+    write(JavaFile.builder(packageName, typeSpec).build());
   }
 
   private void write(JavaFile javaFile) {
@@ -61,4 +82,48 @@ private void write(JavaFile javaFile) {
       throw new UncheckedIOException(e);
     }
   }
+
+  @Override
+  public void close() {
+    if (reportClassName == null) {
+      return;
+    }
+
+    TypeSpec.Builder reportBuilder =
+        markAsGenerated(TypeSpec.classBuilder(reportClassName))
+            .addModifiers(Modifier.PUBLIC)
+            .addModifiers(Modifier.FINAL)
+            .addMethod(MethodSpec.constructorBuilder().addModifiers(Modifier.PRIVATE).build());
+
+    CodeBlock classBySchemaIdFieldEntries =
+        classNameBySchemaId.entrySet().stream()
+            .map(
+                schemaIdToClassName ->
+                    CodeBlock.of(
+                        "$T.entry($S,$T.class)",
+                        Map.class,
+                        schemaIdToClassName.getKey(),
+                        schemaIdToClassName.getValue()))
+            .collect(CodeBlock.joining(","));
+
+    FieldSpec classBySchemaIdField =
+        FieldSpec.builder(
+                ParameterizedTypeName.get(Map.class, String.class, Class.class), "classBySchemaId")
+            .addModifiers(Modifier.PUBLIC)
+            .addModifiers(Modifier.STATIC)
+            .addModifiers(Modifier.FINAL)
+            .initializer("$T.ofEntries($L)", Map.class, classBySchemaIdFieldEntries)
+            .build();
+
+    reportBuilder.addField(classBySchemaIdField);
+
+    write(JavaFile.builder(reportClassName.packageName(), reportBuilder.build()).build());
+  }
+
+  private TypeSpec.Builder markAsGenerated(TypeSpec.Builder typeBuilder) {
+    return typeBuilder.addAnnotation(
+        AnnotationSpec.builder(Generated.class)
+            .addMember("value", "$S", GenerateRecordsFromJsonSchemas.class.getName())
+            .build());
+  }
 }

core/src/main/java/com/cosium/json_schema_to_java_record/JsonSchemaContent.java

@@ -167,7 +167,7 @@ public TypeName writeJavaType(
         .map(ClassName::bestGuess)
         .forEach(typeBuilder::addSuperinterface);
 
-    javaTypes.write(className.packageName(), typeBuilder);
+    javaTypes.write($id, className.packageName(), typeBuilder);
 
     return className;
   }

tests/src/test/java/com/cosium/json_schema_to_java_record_tests/case1/package-info.java

@@ -18,7 +18,8 @@
           javaTypeQualifiedName = "com.cosium.json_schema_to_java_record_tests.case1.Country",
           javaInterfaceQualifiedNames =
               "com.cosium.json_schema_to_java_record_tests.case1.Location"),
-    })
+    },
+    reportClassQualifiedName = "com.cosium.json_schema_to_java_record_tests.case1.Report")
 package com.cosium.json_schema_to_java_record_tests.case1;
 
 import com.cosium.json_schema_to_java_record_api.GenerateRecordsFromJsonSchemas;