refactor: move towards annotation hash generators.

accounting_reporting_core/src/main/java/org/cardanofoundation/lob/app/accounting_reporting_core/service/internal/LOBVersionProcessor.java

@@ -0,0 +1,84 @@
+package org.cardanofoundation.lob.app.accounting_reporting_core.service.internal;
+
+import com.google.auto.service.AutoService;
+import com.squareup.javapoet.JavaFile;
+import com.squareup.javapoet.MethodSpec;
+import com.squareup.javapoet.TypeSpec;
+import org.cardanofoundation.lob.app.accounting_reporting_core.domain.core.annotations.LOBVersionSinkRelevant;
+import org.cardanofoundation.lob.app.accounting_reporting_core.domain.core.annotations.LOBVersionSourceRelevant;
+
+import javax.annotation.processing.*;
+import javax.lang.model.SourceVersion;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.Modifier;
+import javax.lang.model.element.TypeElement;
+import javax.tools.Diagnostic;
+import java.io.IOException;
+import java.util.Set;
+
+@AutoService(Processor.class)
+@SupportedAnnotationTypes({
+        "org.cardanofoundation.lob.app.accounting_reporting_core.domain.core.annotations.LOBVersionSourceRelevant",
+        "org.cardanofoundation.lob.app.accounting_reporting_core.domain.core.annotations.LOBVersionSinkRelevant"
+})
+@SupportedSourceVersion(SourceVersion.RELEASE_21)
+public class LOBVersionProcessor extends AbstractProcessor {
+
+    private Messager messager;
+
+    @Override
+    public synchronized void init(ProcessingEnvironment processingEnv) {
+        super.init(processingEnv);
+        messager = processingEnv.getMessager();
+        messager.printMessage(Diagnostic.Kind.NOTE, "Initializing LOBVersionProcessor...");
+    }
+
+    @Override
+    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
+        messager.printMessage(Diagnostic.Kind.NOTE, "Generating class based on: LOBVersionSourceRelevant and LOBVersionSinkRelevant annotations");
+
+        // Collect all elements (fields) annotated with @LOBVersionSourceRelevant and @LOBVersionSinkRelevant
+        Set<? extends Element> sourceElements = roundEnv.getElementsAnnotatedWith(LOBVersionSourceRelevant.class);
+        Set<? extends Element> sinkElements = roundEnv.getElementsAnnotatedWith(LOBVersionSinkRelevant.class);
+
+        // Generate code to compute hash
+        if (!sourceElements.isEmpty()) {
+            generateHashMethod(sourceElements, "computeSourceHash", "LOBVersionSourceRelevant");
+        }
+
+        if (!sinkElements.isEmpty()) {
+            generateHashMethod(sinkElements, "computeSinkHash", "LOBVersionSinkRelevant");
+        }
+
+        return true; // annotations are claimed by this processor
+    }
+
+    private void generateHashMethod(Set<? extends Element> elements, String methodName, String annotationType) {
+        TypeSpec.Builder classBuilder = TypeSpec.classBuilder(methodName + "Generator")
+                .addModifiers(Modifier.PUBLIC, Modifier.FINAL);
+
+        MethodSpec.Builder methodBuilder = MethodSpec.methodBuilder(methodName)
+                .addModifiers(Modifier.PUBLIC, Modifier.STATIC)
+                .returns(String.class)
+                .addParameter(Object.class, "obj")
+                .addStatement("StringBuilder builder = new StringBuilder()");
+
+        for (Element element : elements) {
+            String fieldName = element.getSimpleName().toString();
+            methodBuilder.addStatement("builder.append(obj.getClass().getDeclaredField($S).get(obj))", fieldName);
+        }
+
+        methodBuilder.addStatement("return org.cardanofoundation.lob.app.support.crypto.SHA3.digestAsHex(builder.toString())");
+
+        classBuilder.addMethod(methodBuilder.build());
+
+        JavaFile javaFile = JavaFile.builder("org.cardanofoundation.lob.app.accounting_reporting_core.generated", classBuilder.build())
+                .build();
+
+        try {
+            javaFile.writeTo(processingEnv.getFiler());
+        } catch (IOException e) {
+            messager.printMessage(Diagnostic.Kind.ERROR, e.toString());
+        }
+    }
+}

build.gradle.kts

@@ -48,6 +48,7 @@ subprojects {
         }
     }
 
+
     extra["springBootVersion"] = "3.3.3"
     extra["springCloudVersion"] = "2023.0.0"
     extra["springModulithVersion"] = "1.2.3"
@@ -95,6 +96,11 @@ subprojects {
         implementation("org.apache.commons:commons-collections4:4.4")
         implementation("org.javers:javers-core:7.6.1")
 
+        compileOnly("com.google.auto.service:auto-service:1.1.1")
+        annotationProcessor("com.google.auto.service:auto-service:1.1.1")
+
+        implementation("com.squareup:javapoet:1.13.0")
+
         compileOnly("org.projectlombok:lombok:1.18.32")
         annotationProcessor("org.projectlombok:lombok:1.18.32")
         implementation("org.springdoc:springdoc-openapi-starter-webmvc-ui:2.5.0")