convert find-output to GraphML to visualize directory structures in yEd

FilesTreeToGraphML.java

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static java.nio.file.Files.newInputStream;

public class FilesTreeToGraphML {

	public static void main(String[] args) {
		(new FilesTreeToGraphML()).run();
	}

	private void run() {
		/*
		Expects a textfile as input that contains the output of a tree or find command to list
		directories and files.
		This linux-command "find -type d > dev.txt" for instance collects all directories starting
		from where it gets run. The output will look like this (remove the first line of just "."):
		.
		./dir1
		./dir1/dir2
		./dir1/dir3
		./dir1/dir3/dir4
		./dir5/dir6
		*/
		Path input = Paths.get("/Users/benja/Desktop/dev.txt");
		String filename = input.getFileName().toString();
		filename = filename.substring(0, filename.lastIndexOf('.'));
		Path output = input.resolveSibling(filename + ".graphml");

		Node root = new Node(filename.toUpperCase());

		try (BufferedReader lines = new BufferedReader(new InputStreamReader(newInputStream(input)))) {
			String line;
			while ((line = lines.readLine()) != null) {
				String[] nodeNames = line.substring(2).split("/");
				Node parent = root;
				for (String nodeName : nodeNames) {
					parent = parent.addChildIfAbsent(nodeName.replaceAll("&", "&"));
				}
			}
		} catch (IOException ignored) {}

		List<Node> nodes = new ArrayList<>();
		List<Edge> edges = new ArrayList<>();
		root.collectNodesAndBuildEdges(nodes, edges);

		doExport(nodes, edges, output);
	}

	class Node {

		String name;
		Map<String, Node> children = new HashMap<>();

		Node(String name) {
			this.name = name;
		}

		Node addChildIfAbsent(String nodeName) {
			children.putIfAbsent(nodeName, new Node(nodeName));
			return children.get(nodeName);
		}

		void collectNodesAndBuildEdges(List<Node> nodes, List<Edge> edges) {
			nodes.add(this);
			children.values().forEach(child -> {
				edges.add(new Edge(this, child));
				child.collectNodesAndBuildEdges(nodes, edges);
			});
		}
	}

	class Edge {

		Node from, to;

		Edge(Node from, Node to) {
			this.from = from;
			this.to = to;
		}
	}

	// GraphML Exporter

	private static PrintWriter output;

	private void doExport(List<FilesTreeToGraphML.Node> nodes, List<FilesTreeToGraphML.Edge> edges, Path path) {
		try {
			output = new PrintWriter(path.toFile());
		} catch (FileNotFoundException ignored) {}

		output.println("<graphml xmlns=\"http://graphml.graphdrawing.org/xmlns\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:y=\"http://www.yworks.com/xml/graphml\" xmlns:yed=\"http://www.yworks.com/xml/yed/3\" xsi:schemaLocation=\"http://graphml.graphdrawing.org/xmlns http://www.yworks.com/xml/schema/graphml/1.1/ygraphml.xsd\">");
		output.println("\t<key attr.name=\"description\" attr.type=\"string\" for=\"node\" id=\"d5\"/>");
		output.println("\t<key for=\"node\" id=\"d6\" yfiles.type=\"nodegraphics\"/>");
		output.println("\t<key attr.name=\"description\" attr.type=\"string\" for=\"edge\" id=\"d9\"/>");
		output.println("\t<key for=\"edge\" id=\"d10\" yfiles.type=\"edgegraphics\"/>");
		output.println("<graph>");

		for (FilesTreeToGraphML.Node node : nodes) {
			writeNode(node.hashCode(), node.name);
		}

		for (FilesTreeToGraphML.Edge edge : edges) {
			writeEdge(edge.hashCode(), edge.from.hashCode(), edge.to.hashCode());
		}

		output.println("</graph>");
		output.println("</graphml>");
		output.close();
	}

	private void writeNode(int ID, String name) {
		output.println("<node id=" + '"' + ID + '"' + ">" +
				"<data key=\"d6\">" +
				"<y:ShapeNode><y:Fill color=\"#FFCC00\" transparent=\"false\"/>" +
				"<y:BorderStyle color=\"#FF0000\" type=\"line\" width=\"1.0\"/>" +
				"<y:NodeLabel textColor=\"#000000\">" + name + "</y:NodeLabel>" +
				"<y:Shape type=\"ellipse\"/></y:ShapeNode></data></node>");
	}

	private void writeEdge(int ID, int sourceID, int targetID) {
		output.println("<edge id=" + '"' + ID + '"' + " source=" + '"' + sourceID + '"' + " target=" + '"' + targetID + '"' + ">" +
				"<data key=\"d9\"><![CDATA[Edge ID: " + ID + "]]></data>" +
				"<data key=\"d10\"><y:BezierEdge>" +
				"<y:LineStyle color=\"#000000\" type=\"line\" width=\"1.0\"/>" +
				"<y:Arrows source=\"none\" target=\"standard\"/>" +
				"</y:BezierEdge></data></edge>");
	}
}

Example result of a directory structure. The Circular Layout algorithm in yEd was applied: