pdfbox: how to solve font (STSong-Light) problem when converting pdf to image?

I'm using pdfbox 2.0.26 to convert pdf to image. The maven dependencies are as following.

        <dependency>
            <groupId>org.apache.pdfbox</groupId>
            <artifactId>fontbox</artifactId>
            <version>2.0.26</version>
        </dependency>

        <dependency>
            <groupId>org.apache.pdfbox</groupId>
            <artifactId>pdfbox</artifactId>
            <version>2.0.26</version>
        </dependency>

The program that I wrote is like

        FileInputStream fin = new FileInputStream("/path/to/sample.pdf");
        try(final PDDocument doc = PDDocument.load(fin)){

            PDFRenderer pdfRenderer = new PDFRenderer((doc));

            BufferedImage bim = pdfRenderer.renderImageWithDPI(0, 300, ImageType.RGB);
            File myObj = new File("/path/to/sample.png");
            FileOutputStream fos = new FileOutputStream(myObj);
            ImageIOUtil.writeImage(bim, "png", fos);
            fin.close();
            fos.close();

        } catch (IOException e) {
            System.out.println("error");
        }

It works fine on my macOS (although the fonts in the image is different from the one in the pdf), but the Chinese characters are lost when I run it on the linux server.

The source PDF file can be found here the source file. I detected the font using adobe reader, the result are pasted as following.

The resulting image file is like:

What shall I do to solve the problem? Thank you