Getting some information with JavaParser

Bla.java

import com.github.javaparser.JavaParser;
import com.github.javaparser.ast.CompilationUnit;
import com.github.javaparser.ast.Modifier;
import com.github.javaparser.ast.body.ClassOrInterfaceDeclaration;
import com.github.javaparser.ast.body.FieldDeclaration;
import com.github.javaparser.ast.body.MethodDeclaration;
import com.github.javaparser.ast.body.VariableDeclarator;

import java.util.ArrayList;
import java.util.List;

public class FieldNames {

    public static void main(String[] args) {
        String s = "public class X{public int a, b; public void zzz(){}} class Y{String y;}";
        CompilationUnit cu = JavaParser.parse(s);

        List<ClassOrInterfaceDeclaration> classes = cu.findAll(ClassOrInterfaceDeclaration.class);
        for (ClassOrInterfaceDeclaration coid : classes) {
            String className = coid.getNameAsString();
            System.out.println("class: " + className);
            for (FieldDeclaration field : coid.getFields()) {
                List<String> modifierNames = new ArrayList<>();
                for (Modifier modifier : field.getModifiers()) {
                    modifierNames.add(modifier.getKeyword().asString());
                }
                List<String> variableNames = new ArrayList<>();
                for (VariableDeclarator variable : field.getVariables()) {
                    variableNames.add(variable.getNameAsString());
                }
                System.out.println("field: " + modifierNames + variableNames);
            }
            for (MethodDeclaration method : coid.getMethods()) {
                String methodName = method.getNameAsString();
                List<String> modifierNames = new ArrayList<>();
                for (Modifier modifier : method.getModifiers()) {
                    modifierNames.add(modifier.getKeyword().asString());
                }
                System.out.println("method: " + modifierNames + methodName);
            }
        }
    }
}