Converting HTML to PDF using iText

后端未结

关注

 2  1985

I am posting this question because many developers ask more or less the same question in different forms. I will answer this question myself (I am the Founder/CTO of iText G

相关标签:

2条回答

再見小時候

2020-11-22 02:27
Why your code doesn't work

As explained in the introduction of the HTML to PDF tutorial, HTMLWorker has been deprecated many years ago. It wasn't intended to convert complete HTML pages. It doesn't know that an HTML page has a <head> and a <body> section; it just parses all the content. It was meant to parse small HTML snippets, and you could define styles using the StyleSheet class; real CSS wasn't supported.

Then came XML Worker. XML Worker was meant as a generic framework to parse XML. As a proof of concept, we decided to write some XHTML to PDF functionality, but we didn't support all of the HTML tags. For instance: forms weren't supported at all, and it was very hard to support CSS that is used to position content. Forms in HTML are very different from forms in PDF. There was also a mismatch between the iText architecture and the architecture of HTML + CSS. Gradually, we extended XML Worker, mostly based on requests from customers, but XML Worker became a monster with many tentacles.

Eventually, we decided to rewrite iText from scratch, with the requirements for HTML + CSS conversion in mind. This resulted in iText 7. On top of iText 7, we created several add-ons, the most important one in this context being pdfHTML.

How to solve the problem

Using the latest version of iText (iText 7.1.0 + pdfHTML 2.0.0) the code to convert the HTML from the question to PDF is reduced to this snippet:
```
public static final String SRC = "src/main/resources/html/sample.html";
public static final String DEST = "target/results/sample.pdf";
public void createPdf(String src, String dest) throws IOException {
    HtmlConverter.convertToPdf(new File(src), new File(dest));
}
```
The result looks like this:

As you can see, this is pretty much the result you'd expect. Since iText 7.1.0 / pdfHTML 2.0.0, the default font is Times-Roman. The CSS is being respected: the image is now floating on the right.

Some additional thoughts.

Developers often feel opposed to upgrade to a newer iText version when I give the advice to upgrade to iText 7 / pdfHTML 2. Allow me to answer to the top 3 of arguments I hear:

I need to use the free iText, and iText 7 isn't free / the pdfHTML add-on is closed source.

iText 7 is released using the AGPL, just like iText 5 and XML Worker. The AGPL allows free use in the sense of free of charge in the context of open source projects. If you are distributing a closed source / proprietary product (e.g. you use iText in a SaaS context), you can't use iText for free; in that case, you have to purchase a commercial license. This was already true for iText 5; this is still true for iText 7. As for versions prior to iText 5: you shouldn't use these at all. Regarding pdfHTML: the first versions were indeed only available as closed source software. We have had heavy discussion within iText Group: on the one hand, there were the people who wanted to avoid the massive abuse by companies who don't listen to their developers when those developers tell the powers that be that open source isn't the same as free. Developers were telling us that their boss forced them to do the wrong thing, and that they couldn't convince their boss to purchase a commercial license. On the other hand, there were the people who argued that we shouldn't punish developers for the wrong behavior of their bosses. Eventually, the people in favor of open sourcing pdfHTML, that is: the developers at iText, won the argument. Please prove that they weren't wrong, and use iText correctly: respect the AGPL if you're using iText for free; make sure that your boss purchases a commercial license if you're using iText in a closed source context.

I need to maintain a legacy system, and I have to use an old iText version.

Seriously? Maintenance also involves applying upgrades and migrating to new versions of the software you're using. As you can see, the code needed when using iText 7 and pdfHTML is very simple, and less error-prone than the code needed before. A migration project shouldn't take too long.

I've only just started and I didn't know about iText 7; I only found out after I finished my project.

That's why I'm posting this question and answer. Think of yourself as an eXtreme Programmer. Throw away all of your code, and start anew. You'll notice that it's not as much work as you imagined, and you'll sleep better knowing that you've made your project future-proof because iText 5 is being phased out. We still offer support to paying customers, but eventually, we'll stop supporting iText 5 altogether.
0 讨论(0)
发布评论:

提交评论
- 加载中...

小蘑菇

2020-11-22 02:40

Use iText 7 and this code:

public void generatePDF(String htmlFile) {
    try {

        //HTML String
        String htmlString = htmlFile;
        //Setting destination 
        FileOutputStream fileOutputStream = new FileOutputStream(new File(dirPath + "/USER-16-PF-Report.pdf"));

        PdfWriter pdfWriter = new PdfWriter(fileOutputStream);
        ConverterProperties converterProperties = new ConverterProperties();
        PdfDocument pdfDocument = new PdfDocument(pdfWriter);

        //For setting the PAGE SIZE
        pdfDocument.setDefaultPageSize(new PageSize(PageSize.A3));

        Document document = HtmlConverter.convertToDocument(htmlFile, pdfDocument, converterProperties);
        document.close();
    } 
    catch (Exception e) {
         e.printStackTrace();
    }

}

0 讨论(0)

Converting HTML to PDF using iText

Why your code doesn't work

How to solve the problem

Some additional thoughts.