CleanPoJo.java

import com.github.javaparser.StaticJavaParser;
import com.github.javaparser.ast.CompilationUnit;
import com.github.javaparser.ast.body.ClassOrInterfaceDeclaration;
import com.github.javaparser.ast.body.ConstructorDeclaration;
import com.github.javaparser.ast.body.MethodDeclaration;
import com.github.javaparser.ast.expr.MarkerAnnotationExpr;
import com.github.javaparser.ast.expr.NormalAnnotationExpr;
import com.github.javaparser.ast.visitor.ModifierVisitor;
import com.github.javaparser.ast.visitor.Visitable;
import com.github.javaparser.printer.PrettyPrinterConfiguration;

public class CleanPoJo {


    public String clean(String code) {


        CompilationUnit unit = StaticJavaParser.parse(code);


        cleanMethodDeclaration(unit);
        cleanConstructorDeclaration(unit);
        cleanAnnotation(unit);
        addLombokOnClassOrInterfaceDeclaration(unit);


        PrettyPrinterConfiguration configuration = new PrettyPrinterConfiguration();

        configuration.setEndOfLineCharacter("\n");
        configuration.setOrderImports(true);

        return unit.toString(configuration);
    }

    private void cleanAnnotation(CompilationUnit unit) {
        unit.accept(new ModifierVisitor<Object>() {


            @Override
            public Visitable visit(NormalAnnotationExpr n, Object arg) {
                return null;
            }


            @Override
            public Visitable visit(MarkerAnnotationExpr n, Object arg) {
                return null;
            }
        }, null);
    }

    private void addLombokOnClassOrInterfaceDeclaration(CompilationUnit unit) {


        unit.accept(new ModifierVisitor<Object>() {


            @Override
            public Visitable visit(ClassOrInterfaceDeclaration n, Object arg) {
                if (!n.getAnnotationByClass(lombok.Data.class)
                        .isPresent()) {

                    n.addAndGetAnnotation(lombok.Data.class);
                }

                if (!n.getAnnotationByClass(lombok.AllArgsConstructor.class)
                        .isPresent()) {

                    n.addAndGetAnnotation(lombok.AllArgsConstructor.class);
                }

                if (!n.getAnnotationByClass(lombok.NoArgsConstructor.class)
                        .isPresent()) {

                    n.addAndGetAnnotation(lombok.NoArgsConstructor.class);
                }

                if (!n.getAnnotationByClass(lombok.experimental.FieldNameConstants.class)
                        .isPresent()) {

                    n.addAndGetAnnotation(lombok.experimental.FieldNameConstants.class);
                }
                return super.visit(n, arg);

            }

        }, null);
    }


    private void cleanConstructorDeclaration(CompilationUnit unit) {
        unit.accept(new ModifierVisitor<Object>() {


            @Override
            public Visitable visit(final ConstructorDeclaration n, final Object arg) {
                return null;

            }


        }, null);
    }

    private void cleanMethodDeclaration(CompilationUnit unit) {
        unit.accept(new ModifierVisitor<Object>() {


            @Override
            public Visitable visit(MethodDeclaration n, Object arg) {


                return null;


            }

        }, null);
    }
}