Spark graphx moved to a new project due to a incompatibility of scala compiler

annotations/annotation-processing/src/main/java/com/baeldung/annotation/processor/BuilderProcessor.java

@@ -0,0 +1,123 @@
+package com.baeldung.annotation.processor;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import javax.annotation.processing.*;
+import javax.lang.model.SourceVersion;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.TypeElement;
+import javax.lang.model.type.ExecutableType;
+import javax.tools.Diagnostic;
+import javax.tools.JavaFileObject;
+
+import com.google.auto.service.AutoService;
+
+@SupportedAnnotationTypes("com.baeldung.annotation.processor.BuilderProperty")
+@SupportedSourceVersion(SourceVersion.RELEASE_8)
+@AutoService(Processor.class)
+public class BuilderProcessor extends AbstractProcessor {
+
+    @Override
+    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
+        for (TypeElement annotation : annotations) {
+
+            Set<? extends Element> annotatedElements = roundEnv.getElementsAnnotatedWith(annotation);
+
+            Map<Boolean, List<Element>> annotatedMethods = annotatedElements.stream().collect(Collectors.partitioningBy(element -> ((ExecutableType) element.asType()).getParameterTypes().size() == 1 && element.getSimpleName().toString().startsWith("set")));
+
+            List<Element> setters = annotatedMethods.get(true);
+            List<Element> otherMethods = annotatedMethods.get(false);
+
+            otherMethods.forEach(element -> processingEnv.getMessager().printMessage(Diagnostic.Kind.ERROR, "@BuilderProperty must be applied to a setXxx method with a single argument", element));
+
+            if (setters.isEmpty()) {
+                continue;
+            }
+
+            String className = ((TypeElement) setters.get(0).getEnclosingElement()).getQualifiedName().toString();
+
+            Map<String, String> setterMap = setters.stream().collect(Collectors.toMap(setter -> setter.getSimpleName().toString(), setter -> ((ExecutableType) setter.asType()).getParameterTypes().get(0).toString()));
+
+            try {
+                writeBuilderFile(className, setterMap);
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+
+        }
+
+        return true;
+    }
+
+    private void writeBuilderFile(String className, Map<String, String> setterMap) throws IOException {
+
+        String packageName = null;
+        int lastDot = className.lastIndexOf('.');
+        if (lastDot > 0) {
+            packageName = className.substring(0, lastDot);
+        }
+
+        String simpleClassName = className.substring(lastDot + 1);
+        String builderClassName = className + "Builder";
+        String builderSimpleClassName = builderClassName.substring(lastDot + 1);
+
+        JavaFileObject builderFile = processingEnv.getFiler().createSourceFile(builderClassName);
+        try (PrintWriter out = new PrintWriter(builderFile.openWriter())) {
+
+            if (packageName != null) {
+                out.print("package ");
+                out.print(packageName);
+                out.println(";");
+                out.println();
+            }
+
+            out.print("public class ");
+            out.print(builderSimpleClassName);
+            out.println(" {");
+            out.println();
+
+            out.print("    private ");
+            out.print(simpleClassName);
+            out.print(" object = new ");
+            out.print(simpleClassName);
+            out.println("();");
+            out.println();
+
+            out.print("    public ");
+            out.print(simpleClassName);
+            out.println(" build() {");
+            out.println("        return object;");
+            out.println("    }");
+            out.println();
+
+            setterMap.entrySet().forEach(setter -> {
+                String methodName = setter.getKey();
+                String argumentType = setter.getValue();
+
+                out.print("    public ");
+                out.print(builderSimpleClassName);
+                out.print(" ");
+                out.print(methodName);
+
+                out.print("(");
+
+                out.print(argumentType);
+                out.println(" value) {");
+                out.print("        object.");
+                out.print(methodName);
+                out.println("(value);");
+                out.println("        return this;");
+                out.println("    }");
+                out.println();
+            });
+
+            out.println("}");
+
+        }
+    }
+
+}

annotations/annotation-processing/src/main/java/com/baeldung/annotation/processor/BuilderProperty.java

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+package com.baeldung.annotation.processor;
+
+import java.lang.annotation.*;
+
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.SOURCE)
+public @interface BuilderProperty {
+}

annotations/annotation-processing/src/main/resources/logback.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>