jmini/decodeDiagram.java

## decodeDiagram.java
///usr/bin/env jbang "$0" "$@" ; exit $?

//DEPS com.github.vlsi.mxgraph:jgraphx:4.2.2
//JAVA 8

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.URLDecoder;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Base64;
import java.util.zip.DataFormatException;
import java.util.zip.Inflater;

import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Node;

import com.mxgraph.util.mxXmlUtils;

public class decodeDiagram {

    public static void main(String... args) throws Exception {
        if (args == null || args.length != 1) {
            System.err.println("Usage: " + decodeDiagram.class.getSimpleName() + " <file path>");
            System.exit(1);
            throw new IllegalStateException("Unreachable code");
        }

        Path file = Paths.get(args[0]);
        if (!Files.exists(file)) {
            System.err.println("Can not read file: " + file);
            System.exit(1);
            throw new IllegalStateException("Unreachable code");
        }

        String content = new String(Files.readAllBytes(file), StandardCharsets.UTF_8);

        decodeDiagram instance = new decodeDiagram();
        Document document = instance.getDiagramData(content);

        printDocument(document, System.out);
    }

    public Document getDiagramData(String xmlString) throws DataFormatException, IOException {
        Document xmlDocument = mxXmlUtils.parseXml(xmlString);

        Node diagram = xmlDocument.getElementsByTagName("diagram")
                .item(0);
        String textContent = diagram.getTextContent();

        if (!textContent.startsWith("<")) {
            byte[] compressed = base64Decode(textContent);
            byte[] decompressed = inflate(compressed);
            textContent = urlDecode(new String(decompressed));

            Document expanded = mxXmlUtils.parseXml(textContent);
            Node imported = xmlDocument.importNode(expanded.getFirstChild(), true);
            diagram.setTextContent(null);
            diagram.appendChild(imported);
        }

        return xmlDocument;
    }

    private byte[] inflate(byte[] compressed) throws IOException, DataFormatException {
        int compressedDataLength = 0;
        Inflater compresser = new Inflater(true);
        compresser.setInput(compressed, 0, compressed.length);
        ByteArrayOutputStream o = new ByteArrayOutputStream(compressed.length);
        byte[] result = new byte[1024];
        try {
            while (!compresser.finished()) {
                compressedDataLength = compresser.inflate(result);
                if (compressedDataLength == 0) {
                    break;
                }
                o.write(result, 0, compressedDataLength);
            }
        } finally {
            o.close();
        }
        compresser.end();
        return o.toByteArray();
    }

    private byte[] base64Decode(String input) {
        return Base64.getDecoder()
                .decode(input);
    }

    private String urlDecode(String input) {
        return URLDecoder.decode(input);
    }

    public static void printDocument(Document doc, OutputStream out) throws IOException, TransformerException {
        TransformerFactory tf = TransformerFactory.newInstance();
        Transformer transformer = tf.newTransformer();
        transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
        transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
        transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");

        transformer.transform(new DOMSource(doc),
                new StreamResult(new OutputStreamWriter(out, "UTF-8")));
    }
}
	///usr/bin/env jbang "$0" "$@" ; exit $?

	//DEPS com.github.vlsi.mxgraph:jgraphx:4.2.2
	//JAVA 8

	import java.io.ByteArrayOutputStream;
	import java.io.IOException;
	import java.io.OutputStream;
	import java.io.OutputStreamWriter;
	import java.net.URLDecoder;
	import java.nio.charset.StandardCharsets;
	import java.nio.file.Files;
	import java.nio.file.Path;
	import java.nio.file.Paths;
	import java.util.Base64;
	import java.util.zip.DataFormatException;
	import java.util.zip.Inflater;

	import javax.xml.transform.OutputKeys;
	import javax.xml.transform.Transformer;
	import javax.xml.transform.TransformerException;
	import javax.xml.transform.TransformerFactory;
	import javax.xml.transform.dom.DOMSource;
	import javax.xml.transform.stream.StreamResult;

	import org.w3c.dom.Document;
	import org.w3c.dom.Node;

	import com.mxgraph.util.mxXmlUtils;

	public class decodeDiagram {

	public static void main(String... args) throws Exception {
	if (args == null \|\| args.length != 1) {
	System.err.println("Usage: " + decodeDiagram.class.getSimpleName() + " <file path>");
	System.exit(1);
	throw new IllegalStateException("Unreachable code");
	}

	Path file = Paths.get(args[0]);
	if (!Files.exists(file)) {
	System.err.println("Can not read file: " + file);
	System.exit(1);
	throw new IllegalStateException("Unreachable code");
	}

	String content = new String(Files.readAllBytes(file), StandardCharsets.UTF_8);

	decodeDiagram instance = new decodeDiagram();
	Document document = instance.getDiagramData(content);

	printDocument(document, System.out);
	}

	public Document getDiagramData(String xmlString) throws DataFormatException, IOException {
	Document xmlDocument = mxXmlUtils.parseXml(xmlString);

	Node diagram = xmlDocument.getElementsByTagName("diagram")
	.item(0);
	String textContent = diagram.getTextContent();

	if (!textContent.startsWith("<")) {
	byte[] compressed = base64Decode(textContent);
	byte[] decompressed = inflate(compressed);
	textContent = urlDecode(new String(decompressed));

	Document expanded = mxXmlUtils.parseXml(textContent);
	Node imported = xmlDocument.importNode(expanded.getFirstChild(), true);
	diagram.setTextContent(null);
	diagram.appendChild(imported);
	}

	return xmlDocument;
	}

	private byte[] inflate(byte[] compressed) throws IOException, DataFormatException {
	int compressedDataLength = 0;
	Inflater compresser = new Inflater(true);
	compresser.setInput(compressed, 0, compressed.length);
	ByteArrayOutputStream o = new ByteArrayOutputStream(compressed.length);
	byte[] result = new byte[1024];
	try {
	while (!compresser.finished()) {
	compressedDataLength = compresser.inflate(result);
	if (compressedDataLength == 0) {
	break;
	}
	o.write(result, 0, compressedDataLength);
	}
	} finally {
	o.close();
	}
	compresser.end();
	return o.toByteArray();
	}

	private byte[] base64Decode(String input) {
	return Base64.getDecoder()
	.decode(input);
	}

	private String urlDecode(String input) {
	return URLDecoder.decode(input);
	}

	public static void printDocument(Document doc, OutputStream out) throws IOException, TransformerException {
	TransformerFactory tf = TransformerFactory.newInstance();
	Transformer transformer = tf.newTransformer();
	transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
	transformer.setOutputProperty(OutputKeys.INDENT, "yes");
	transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
	transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");

	transformer.transform(new DOMSource(doc),
	new StreamResult(new OutputStreamWriter(out, "UTF-8")));
	}
	}