Render web documents as PDF, PNG, and JPEG files Leave feedback

GroupDocs.Viewer for Java allows you to render web documents as PDF, PNG, and JPEG files. Use this library to view web files within your Java application.

To start using the GroupDocs.Viewer API, create a Viewer class instance. Pass a web document you want to view to the class constructor. You can load the document from a file or stream. Call one of the Viewer.view method overloads to convert the document to PDF or image format. These methods allow you to render the entire document or specific pages.

View web files online View demos and examples on GitHub

GroupDocs.Viewer supports the following web file formats:

• Hypertext Markup Language Format (.HTML / .HTM)
• MIME HTML Format (.MHTML)
• MHTML Web Archive (.MHT)
• Compiled HTML Help Format (.CHM)

Create a PdfViewOptions class instance and pass it to the Viewer.view method to convert a web file to PDF. The PdfViewOptions class properties allow you to control the conversion process. For instance, you can protect the output PDF file, reorder its pages, and specify the quality of document images. Refer to the following documentation section for details: Rendering to PDF.

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.PdfViewOptions;
// ...

try (Viewer viewer = new Viewer("groupdocs-documentation.mhtml")) {
    // Create a PDF file for the document.
    // Specify the PDF file name.
    PdfViewOptions viewOptions = new PdfViewOptions("output.pdf");
    viewer.view(viewOptions);
}

The following image demonstrates the result:

Create a PngViewOptions class instance and pass it to the Viewer.view method to convert a web file to PNG. Use the PngViewOptions.setHeight and PngViewOptions.setWidth methods to specify the output image size in pixels.

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.PngViewOptions;
// ...

try (Viewer viewer = new Viewer("groupdocs-documentation.mhtml")) {
    // Convert the web file to PNG.
    // {0} is replaced with the page numbers in the output image names.
    PngViewOptions viewOptions = new PngViewOptions("output_{0}.png");
    // Set width and height.
    viewOptions.setWidth(950);
    viewOptions.setHeight(800);
    viewer.view(viewOptions);
}

The following image demonstrates the result:

Create a JpgViewOptions class instance and pass it to the Viewer.view method to convert a web file to JPEG. Use the JpgViewOptions.setHeight and JpgViewOptions.setWidth methods to specify the output image size in pixels.

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.JpgViewOptions;
// ...

try (Viewer viewer = new Viewer("groupdocs-documentation.mhtml")) {
    // Create a JPEG image for each drawing page.
    // {0} is replaced with the current page number in the image name.
    JpgViewOptions viewOptions = new JpgViewOptions("output_{0}.jpg");
    // Set width and height.
    viewOptions.setWidth(1600);
    viewOptions.setHeight(650);
    viewer.view(viewOptions);
}

CHM is a Microsoft proprietary online help format that is often used for software documentation. With GroupDocs.Viewer, you can convert a CHM file to HTML to display this file in a web browser. To do this, create an HtmlViewOptions class instance and pass it to the Viewer.view method. The HtmlViewOptions class properties allow you to control the conversion process. For instance, you can embed all external resources in the generated HTML file, minify the output file, and optimize it for printing. Refer to the following documentation section for details: Rendering to HTML.

To save all elements of an HTML page (including text, graphics, and stylesheets) into a single file, call the HtmlViewOptions.forEmbeddedResources method and specify the output file name.

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.HtmlViewOptions;
// ...

try (Viewer viewer = new Viewer("sample.chm")) {
    // Convert the CHM file to HTML.
    // {0} is replaced with the page numbers in the output file names.
    HtmlViewOptions viewOptions = HtmlViewOptions.forEmbeddedResources("chm_result_{0}.html");
    // Enable the following option to display all CHM content on a single HTML page.
    // viewOptions.setRenderToSinglePage(true);
    viewer.view(viewOptions);
}

The following image demonstrates the result:

If you want to store an HTML file and additional resource files (such as fonts, images, and stylesheets) separately, call the HtmlViewOptions.forExternalResources method and pass the following parameters:

• The output file path format
• The path format for the folder with external resources
• The resource URL format

import com.groupdocs.viewer.Viewer;
import com.groupdocs.viewer.options.HtmlViewOptions;
// ...

try (Viewer viewer = new Viewer("sample.chm")) {
    // Convert the CHM file to HTML.
    // Specify the output file names and location of external resources.
    HtmlViewOptions viewOptions = HtmlViewOptions.forExternalResources("page_{0}.html", "page_{0}/resource_{0}_{1}", "page_{0}/resource_{0}_{1}");
    viewer.view(viewOptions);
}