PMDを用いたJavaソースコードのトークン化とASTツリー生成

ManyTokenizer.java

import net.sourceforge.pmd.lang.ParserOptions;
import net.sourceforge.pmd.lang.ast.JavaCharStream;
import net.sourceforge.pmd.lang.java.Java18Parser;
import net.sourceforge.pmd.lang.java.ast.*;

import java.io.BufferedReader;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class ManyTokenizer {
    static class SimpleJavaParserVisitor extends JavaParserVisitorAdapter {
        int depth = 0;
        @Override
        public Object visit(JavaNode node, Object data) {
            for (int i=0; i<depth; i++) {
                System.out.print(" ");
            }
            System.out.println(node.toString());
            depth++;
            Object returnValue = super.visit(node, data);
            depth--;
            return returnValue;
        }
    }

    public static void main(String[] args) throws IOException {
        Path path = Paths.get("src/main/java/ManyTokenizer.java");
        try (BufferedReader br = Files.newBufferedReader(path)) {
            JavaCharStream javaCharStream = new JavaCharStream(br);
            JavaParserTokenManager javaParserTokenManager = new JavaParserTokenManager(javaCharStream);
            Token token;
            while ((token = javaParserTokenManager.getNextToken()).kind > 0) {
                String desc = String.format("%4d:%-4d %s", token.beginLine, token.beginColumn, token.image);
                System.out.println(desc);
            }
        }
        try (BufferedReader br = Files.newBufferedReader(path)) {
            ParserOptions options = new ParserOptions();
            Java18Parser java18Parser = new Java18Parser(options);
            ASTCompilationUnit unit = (ASTCompilationUnit) java18Parser.parse(path.getFileName().toString(), br);
            SimpleJavaParserVisitor visitor = new SimpleJavaParserVisitor();
            visitor.visit(unit, null);
        }
    }
}