Question

我正在努力将svg文件转换为Swing中的图像。我试着用同样的蜡染库。在浏览器中打开svg文件时，会正确显示图像。但是当执行以下程序将svg转换为Swing中的Image / BufferedImage时，我得到异常，说TranscoderException：null过早结束文件。有人可以帮我解决这个问题吗？

由于

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文件内容：

<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);

这里读者指向文件的开头。

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

读者遍历文件。

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

...

所以这里的读者在文件的末尾，我们已经阅读了整个文件。

        TranscoderInput svgImage = new TranscoderInput(reader);

当代码转换器尝试使用阅读器来读取文件时，没有什么可读的。

选项：

删除所有创建s的代码，以便在将文件传递给代码转换器时读取器位于文件的开头
使用标记和重置将阅读器重置到文件的开头，然后再将其传递给代码转换器
将s而不是阅读器传递给代码转换器

org.apache.batik.transcoder.TranscoderException：null文件的过早结束

1 个答案: