How to use

org.apache.batik.transcoder.image.PNGTranscoder

constructor

@PutMapping(value = "/{modelId}")
@ResponseStatus(value = HttpStatus.OK)
@Authorize(action = Permission.ACTION_UPDATE)
public void saveModel(@PathVariable String modelId,
           @RequestParam Map<String, String> values) throws TranscoderException, IOException {
  Model model = repositoryService.getModel(modelId);
  JSONObject modelJson = JSON.parseObject(model.getMetaInfo());
  modelJson.put(MODEL_NAME, values.get("name"));
  modelJson.put(MODEL_DESCRIPTION, values.get("description"));
  model.setMetaInfo(modelJson.toString());
  model.setName(values.get("name"));
  repositoryService.saveModel(model);
  repositoryService.addModelEditorSource(model.getId(), values.get("json_xml").getBytes("utf-8"));
  InputStream svgStream = new ByteArrayInputStream(values.get("svg_xml").getBytes("utf-8"));
  TranscoderInput input = new TranscoderInput(svgStream);
  PNGTranscoder transcoder = new PNGTranscoder();
  // Setup output
  ByteArrayOutputStream outStream = new ByteArrayOutputStream();
  TranscoderOutput output = new TranscoderOutput(outStream);
  // Do the transformation
  transcoder.transcode(input, output);
  final byte[] result = outStream.toByteArray();
  repositoryService.addModelEditorSourceExtra(model.getId(), result);
  outStream.close();
}

try (FileReader in = new FileReader(svgPath);
  OutputStream out = new FileOutputStream(pngPath)) {
 PNGTranscoder transcoder = new PNGTranscoder();
 transcoder.addTranscodingHint(PNGTranscoder.KEY_WIDTH, w);
 transcoder.addTranscodingHint(PNGTranscoder.KEY_HEIGHT, h);

TranscoderInput input = new TranscoderInput(svgStream);
PNGTranscoder transcoder = new PNGTranscoder();

@VisibleForTesting
PNGTranscoder createPngTranscoder()
{
  return new PNGTranscoder();
}

private byte[] pngBytesFromSvg(String svg) throws TranscoderException {
  final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
  final TranscoderInput input = new TranscoderInput(new StringReader(svg));
  final TranscoderOutput output = new TranscoderOutput(outputStream);
  final PNGTranscoder converter = new PNGTranscoder();
  converter.transcode(input, output);
  byte[] bytes = outputStream.toByteArray();
  try {
    outputStream.close();
  } catch (IOException e) {
    e.printStackTrace();
  }
  return bytes;
}

/**
 * Helper method: creates a valid reference image
 */
public static URL createValidReferenceImage(String svgContent) throws Exception{
  TranscoderInput validSrc = new TranscoderInput(new StringReader(svgContent));
  
  File tmpFile = File.createTempFile(SVGRenderingAccuracyTest.TEMP_FILE_PREFIX,
                    SVGRenderingAccuracyTest.TEMP_FILE_SUFFIX);
  
  TranscoderOutput validDst 
    = new TranscoderOutput(new FileOutputStream(tmpFile));
  
  ImageTranscoder transcoder 
    = new PNGTranscoder();
  
  transcoder.transcode(validSrc, validDst);
  
  tmpFile.deleteOnExit();
  
  return tmpFile.toURI().toURL();
}

public static byte[] convertToPngAsBytes(String path, Map<String, Object> paramMap)
    throws Exception {
  try {
    Document doc = SvgDocumentHelper.loadDocument(path, paramMap);
    PNGTranscoder t = new PNGTranscoder();
    ByteArrayOutputStream output = saveAsBytes(t, doc);
    byte[] ans = output.toByteArray();
    output.close();
    // 加速内存回收
    doc = null;
    return ans;
  } catch (Exception e) {
    log.error("render svg to png error! path:{}, data:{}, e: {}", path, paramMap, e);
    return null;
  }
}

private void convertSvgToPng(File svg, File png) throws Exception {
  String svgUriInput = svg.toURI().toURL().toString();
  TranscoderInput inputSvgImage = new TranscoderInput(svgUriInput);
  //Step-2: Define OutputStream to PNG Image and attach to TranscoderOutput
  OutputStream pngOStream = new FileOutputStream(png);
  TranscoderOutput outputPngImage = new TranscoderOutput(pngOStream);
  // Step-3: Create PNGTranscoder and define hints if required
  PNGTranscoder myConverter = new PNGTranscoder();
  // Step-4: Convert and Write output
  myConverter.transcode(inputSvgImage, outputPngImage);
  // Step 5- close / flush Output Stream
  pngOStream.flush();
  pngOStream.close();
}
public String replaceSvgWithPng(File htmlFile) throws Exception {

/**
 * 将SVG转换成PNG
 *
 * @param path     SVG文件路径
 * @param paramMap 变更参数键值对，key为svg元素Id value为替换内容
 * @throws TranscoderException
 * @throws IOException
 */
public static BufferedImage convertToPngAsImg(String path, Map<String, Object> paramMap)
    throws Exception {
  try {
    Document doc = SvgDocumentHelper.loadDocument(path, paramMap);
    PNGTranscoder t = new PNGTranscoder();
    BufferedImage bf = saveAsImg(t, doc);
    // 加速内存回收
    doc = null;
    return bf;
  } catch (Exception e) {
    log.error("render svg to png error! path:{}, data:{}, e: {}", path, paramMap, e);
    e.printStackTrace();
    return null;
  }
}

/**
 * Returns a transcoder object of the result image type.
 *
 * @return Transcoder object or <code>null</code> if there isn't a proper transcoder.
 */
protected Transcoder getTranscoder(){
  switch(code) {
    case PNG_CODE:
      return new PNGTranscoder();
    case JPEG_CODE:
      return new JPEGTranscoder();
    case TIFF_CODE:
      return new TIFFTranscoder();
    case PDF_CODE:
      try {
        Class pdfClass = Class.forName("org.apache.fop.svg.PDFTranscoder");
        return (Transcoder)pdfClass.getDeclaredConstructor().newInstance();
      } catch(Exception e) {
        return null;
      }
    default:
      return null;
  }
}

 import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.OutputStream;

import org.apache.batik.transcoder.TranscoderInput;
import org.apache.batik.transcoder.TranscoderOutput;
import org.apache.batik.transcoder.image.PNGTranscoder;

public class Test {
  public static void main(String[] args) throws Exception {
    PNGTranscoder t = new PNGTranscoder();
    t.addTranscodingHint(PNGTranscoder.KEY_WIDTH, new Float(12600));
    t.addTranscodingHint(PNGTranscoder.KEY_HEIGHT, new Float(12600));
    FileInputStream fis = new FileInputStream("C:\\StackOverflow\\SVG-logo.svg");
    TranscoderInput input = new TranscoderInput(fis);
    OutputStream ostream = new FileOutputStream("C:\\StackOverflow\\res.png");
    TranscoderOutput output = new TranscoderOutput(ostream);

    System.out.println("AllocatedMemory: \t" + (Runtime.getRuntime().totalMemory() / 1024) + " Kb");
    t.transcode(input, output);
    System.out.println("AllocatedMemory: \t" + (Runtime.getRuntime().totalMemory() / 1024) + " Kb");

    ostream.flush();
    ostream.close();

  }
}

/**
 * Transcode file to PNG.
 *
 * @param file Output filename
 * @param width Width
 * @param height Height
 * @throws IOException On write errors
 * @throws TranscoderException On input/parsing errors.
 */
public void saveAsPNG(File file, int width, int height) throws IOException, TranscoderException {
 PNGTranscoder t = new PNGTranscoder();
 t.addTranscodingHint(PNGTranscoder.KEY_WIDTH, new Float(width));
 t.addTranscodingHint(PNGTranscoder.KEY_HEIGHT, new Float(height));
 transcode(file, t);
}

/**
 * Returns a transcoder object of the result image type.
 *
 * @return Transcoder object or <code>null</code> if there isn't a proper transcoder.
 */
protected Transcoder getTranscoder(){
  switch(code) {
    case PNG_CODE:
      return new PNGTranscoder();
    case JPEG_CODE:
      return new JPEGTranscoder();
    case TIFF_CODE:
      return new TIFFTranscoder();
    case PDF_CODE:
      try {
        Class pdfClass = Class.forName("org.apache.fop.svg.PDFTranscoder");
        return (Transcoder)pdfClass.newInstance();
      } catch(Exception e) {
        return null;
      }
    default:
      return null;
  }
}

/**
 * Transcode file to PNG.
 *
 * @param file Output filename
 * @param width Width
 * @param height Height
 * @throws IOException On write errors
 * @throws TranscoderException On input/parsing errors.
 */
public void saveAsPNG(File file, int width, int height) throws IOException, TranscoderException {
 PNGTranscoder t = new PNGTranscoder();
 t.addTranscodingHint(PNGTranscoder.KEY_WIDTH, new Float(width));
 t.addTranscodingHint(PNGTranscoder.KEY_HEIGHT, new Float(height));
 transcode(file, t);
}

BASE64Decoder decoder = new BASE64Decoder();
 byte[] image = decoder.decodeBuffer(string);
 String fileLocation  = "C:\temp";
 String fileName = "New-" + System.currentTimeMillis();
 File file = new File(fileLocation +File.separator+ fileName + ".svg");
 FileOutputStream fop = new FileOutputStream(file);
 if (!file.exists()) {
  file.createNewFile();
 }
 fop.write(image);
 fop.flush();
 fop.close();
 PNGTranscoder transcoder = new PNGTranscoder();
 TranscoderInput tinput = new TranscoderInput(new FileInputStream(fileLocation + File.separator + fileName +".svg"));
 OutputStream ostream = new FileOutputStream(fileLocation + File.separator + fileName +".png");
 TranscoderOutput toutput = new TranscoderOutput(ostream);
 try {
    transcoder.transcode(tinput, toutput);
 } catch (TranscoderException e) { 
    System.out.println("error*");
     e.printStackTrace();
 }
 ostream.close();

/**
 * 将SVG输入流转换并写入到PNG输出流
 *
 * @param reader SVG字符流
 * @param output PNG输出流
 * @throws TranscoderException 转换异常
 */
public static void svg2png(Reader reader, OutputStream output) throws TranscoderException {
  if (reader == null) {
    throw new IllegalArgumentException("Reader must not be null");
  }
  if (output == null) {
    throw new IllegalArgumentException("OutputStream must not be null");
  }
  Transcoder transcoder = new PNGTranscoder();
  transcoder.transcode(new TranscoderInput(reader), new TranscoderOutput(output));
}

/**
 * 将SVG输入流转换并写入到PNG输出流
 *
 * @param input  SVG输入流
 * @param output PNG输出流
 * @throws TranscoderException 转换异常
 */
public static void svg2png(InputStream input, OutputStream output) throws TranscoderException {
  if (input == null) {
    throw new IllegalArgumentException("InputStream must not be null");
  }
  if (output == null) {
    throw new IllegalArgumentException("OutputStream must not be null");
  }
  Transcoder transcoder = new PNGTranscoder();
  transcoder.transcode(new TranscoderInput(input), new TranscoderOutput(output));
}

private void rasterize(TranscoderInput input, TranscoderOutput output, int width, int height)
{
  PNGTranscoder transcoder = new PNGTranscoder();
  if (width > 0) {
    transcoder.addTranscodingHint(SVGAbstractTranscoder.KEY_WIDTH, new Float(width));
  }
  if (height > 0) {
    transcoder.addTranscodingHint(SVGAbstractTranscoder.KEY_HEIGHT, new Float(height));
  }
  // Set maximum width and height to 8k to avoid DoS attacks
  transcoder.addTranscodingHint(SVGAbstractTranscoder.KEY_MAX_WIDTH, new Float(8192));
  transcoder.addTranscodingHint(SVGAbstractTranscoder.KEY_MAX_HEIGHT, new Float(8192));
  try {
    transcoder.transcode(input, output);
  } catch (TranscoderException ex) {
    this.logger.warn("Failed to rasterize SVG image: {}", ex.getMessage());
  }
}

private void rasterize(TranscoderInput input, TranscoderOutput output, int width, int height)
{
  PNGTranscoder transcoder = new PNGTranscoder();
  if (width > 0) {
    transcoder.addTranscodingHint(SVGAbstractTranscoder.KEY_WIDTH, new Float(width));
  }
  if (height > 0) {
    transcoder.addTranscodingHint(SVGAbstractTranscoder.KEY_HEIGHT, new Float(height));
  }
  // Set maximum width and height to 8k to avoid DoS attacks
  transcoder.addTranscodingHint(SVGAbstractTranscoder.KEY_MAX_WIDTH, new Float(8192));
  transcoder.addTranscodingHint(SVGAbstractTranscoder.KEY_MAX_HEIGHT, new Float(8192));
  try {
    transcoder.transcode(input, output);
  } catch (TranscoderException ex) {
    this.logger.warn("Failed to rasterize SVG image: {}", ex.getMessage());
  }
}

private InputStream renderSVGToInputStream(RenderingContext context, ImageXMLDOM imageSVG) throws IOException {
  PNGTranscoder png = new PNGTranscoder();
  Float width = getDimension(imageSVG.getDocument(), "width") * 8;
  png.addTranscodingHint(SVGAbstractTranscoder.KEY_WIDTH, width);
  Float height = getDimension(imageSVG.getDocument(), "height") * 8;
  png.addTranscodingHint(SVGAbstractTranscoder.KEY_HEIGHT, height);
  TranscoderInput input = new TranscoderInput(imageSVG.getDocument());
  ByteArrayOutputStream os = new ByteArrayOutputStream();
  TranscoderOutput output = new TranscoderOutput(os);
  try {
    png.transcode(input, output);
  } catch (TranscoderException ex) {
    SVGEventProducer eventProducer = SVGEventProducer.Provider.get(
        context.getUserAgent().getEventBroadcaster());
    eventProducer.svgRenderingError(this, ex, imageSVG.getInfo().getOriginalURI());
  } finally {
    os.flush();
    os.close();
  }
  return new ByteArrayInputStream(os.toByteArray());
}