To make a preview image of a PDF document I do use PDFBox that is an Apache library made to work with PDF.

You can install the library manually or use the Maven repository:


<dependency>
<groupId>org.apache.pdfbox<groupId>
<artifactId>pdfbox</artifactId>
<version>1.6.0</version>
<dependency>


To convert the PDF, here it is the code:


PDDocument doc = PDDocument.load("myFile.pdf");
PDPage firstPage = (PDPage) doc.getDocumentCatalog().getAllPages().get(0);
BufferedImage bufferedImage = firstPage.convertToImage();


You can even load the PDF document by a Stream or a Url. You have the first page preview of your PDF file in the BufferdImage variable. Then you can save it into the preferred extension.