org.apache.batik.transcoder.TranscoderException: null Premature end of file

Question

I am struggling to convert svg file to an image in Swing. I tried to use batik library for the same. The svg file when opened in the browser, shows the image correctly. But when the following program is executed to convert svg to an Image / BufferedImage in Swing, I am getting exception saying TranscoderException: null Premature End of File. Can someone please help me out with this?

Thanks

public class TestSymbolCreation {
    static JFrameWin jFrameWindow;
    static Image bufImage;
    public static void main(String args[]) {
        ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
        ScriptEngine scriptEngine = scriptEngineManager.getEngineByName("JavaScript");

        System.out.println(new File(".").getAbsoluteFile());

        File file = new File("./src/resources/milsymbol.js");
        try {
            Reader reader = new FileReader(file);
            scriptEngine.eval(reader);
            TestSymbolCreation testCreation = new TestSymbolCreation();
            scriptEngine.put("testCreation", testCreation);
            scriptEngine.eval("function run(testCreation){testCreation.getCanvas(new ms.Symbol('SFG-UCI----D',{size:35}).asSVG());} run(testCreation);");
        } catch (FileNotFoundException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (ScriptException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    public void getCanvas(String canvas) {
        System.out.println("Value of Canvas111 =>"+canvas);
        bufImage = createImageFromSVG();
        SwingUtilities.invokeLater(runJFrameLater);
    }

    public void test() {
        System.out.println("Test...");
    }

    public Image createImageFromSVG() {
        File file = new File("./src/svgImg.svg");
        System.out.println("File Exists =>"+file.exists());
        System.out.println("File Exists =>"+file.isFile());
        FileReader fr;
        try {
            fr = new FileReader(file);
            BufferedReader reader = new BufferedReader(fr);

            String s = "", line = null;
            try {
                while ((line = reader.readLine()) != null) {
                    s += line;
                }
                System.out.print(s);        
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }

            TranscoderInput svgImage = new TranscoderInput(reader);
            Dimension component = new Dimension();
            component.setSize(800, 800);
            BufferedImageTranscoder transcoder = new BufferedImageTranscoder();
            transcoder.addTranscodingHint(PNGTranscoder.KEY_WIDTH, (float) component.getWidth());
            transcoder.addTranscodingHint(PNGTranscoder.KEY_HEIGHT, (float) component.getHeight());
            try {
                transcoder.transcode(svgImage, null); // Exception thrown at this line
            } catch (TranscoderException e) {
                e.printStackTrace();;
            }

            return transcoder.createImage(60,60);
        } catch (FileNotFoundException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        return null;

    }

    public static class JFrameWin extends JPanel {

        public JFrameWin(){
            this.setSize(300, 200);

            System.out.println("Going to set BufferedImage....");
            JFrame jFrame = new JFrame();
                jFrame.setTitle("Test Rotation!!!");
                jFrame.getContentPane().add(this);
                jFrame.pack();
                jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
                jFrame.setVisible(true);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.drawImage(bufImage, 0, 0, this); // see javadoc for more info on the parameters            
        }
    }

    static Runnable runJFrameLater = new Runnable() {
        @Override
        public void run() {
            jFrameWindow = new JFrameWin();
            jFrameWindow.setVisible(true);
        }
    };



}

SVG file contents:

<svg xmlns="http://www.w3.org/2000/svg" version="1.2" baseProfile="tiny" width="55.3" height="47.425" viewBox="21 18.5 158 135.5"><path d="M25,50 l150,0 0,100 -150,0 z" stroke-width="4" stroke="black" fill="rgb(128,224,255)" fill-opacity="1" ></path><path d="M25,50 L175,150 M25,150 L175,50" stroke-width="4" stroke="black" fill="black" ></path><g transform="translate(0,0)" stroke-width="4" stroke="black" fill="none" ><circle cx="100" cy="30" r="7.5" fill="black" ></circle><circle cx="70" cy="30" r="7.5" fill="black" ></circle><circle cx="130" cy="30" r="7.5" fill="black" ></circle></g></svg>

Answer 1

        BufferedReader reader = new BufferedReader(fr);

Here the reader points to the beginning of the file.

        String s = "", line = null;
        try {
            while ((line = reader.readLine()) != null) {

the reader iterates over the file.

                s += line;
            }
            System.out.print(s);        

...

So here the reader is at the end of the file, we've read the whole of the file.

        TranscoderInput svgImage = new TranscoderInput(reader);

When the transcoder tries to use the reader to read the file, there's nothing to read.

Options:

• remove all the code that creates s so the reader is at the start of the file when you pass it to the transcoder
• use mark and reset to reset the reader to the start of the file before passing it to the transcoder
• pass s rather than the reader to the transcoder