Render Excel and Apple Numbers spreadsheets as HTML, PDF, and image files

GroupDocs.Viewer for Java allows you to render your spreadsheet files in HTML, PDF, PNG, and JPEG formats. You do not need to use Microsoft Excel or other spreadsheet programs to load and view Excel documents within your Java application (web or desktop).

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

View Excel files online View demos and examples on GitHub

Supported Spreadsheet file formats

GroupDocs.Viewer supports the following file formats:

GroupDocs.Viewer can detect the document format automatically based on information in the file header.

Render spreadsheets as HTML

Create a HtmlViewOptions class instance and pass it to the view() method to convert a spreadsheet file to HTML. 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.

Create an HTML file with embedded resources

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.

Example 1: Convert an Excel workbook to HTML

try (Viewer viewer = new Viewer("invoice.xlsx")) {
    // Convert the spreadsheet to HTML.
    // Specify the HTML file names and location of external resources.
    // {0} and {1} are replaced with the current page number and resource name, respectively.
    HtmlViewOptions viewOptions = HtmlViewOptions.forExternalResources("page_{0}.html", "page_{0}/resource_{0}_{1}", "page_{0}/resource_{0}_{1}");
    viewer.view(viewOptions);
}

The following image demonstrates the result:

Render an Excel file to HTML

Example 2: Convert an Apple Numbers spreadsheet to HTML

try (Viewer viewer = new Viewer("Products.numbers")) {
    // Convert the spreadsheet to HTML.
    // {0} is replaced with the current page number in the file names.
    HtmlViewOptions viewOptions = HtmlViewOptions.forEmbeddedResources("page_{0}.html");
    viewer.view(viewOptions);
}

The following image demonstrates the result:

Render an Apple Numbers spreadsheet to HTML

Create an HTML file with external resources

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

Example 1: Convert an Excel workbook to HTML

try(Viewer viewer = new Viewer("invoice.xlsx")){
    // Convert the spreadsheet to HTML.
    // Specify the HTML file names and location of external resources.
    // {0} and {1} are replaced with the current page number and resource name, respectively.
    HtmlViewOptions viewOptions = HtmlViewOptions.forExternalResources("page_{0}.html","page_{0}/resource_{0}_{1}","page_{0}/resource_{0}_{1}");
    viewer.view(viewOptions);
}

Example 2: Convert an Apple Numbers spreadsheet to HTML

try(Viewer viewer = new Viewer("Products.numbers")){
    // Convert the spreadsheet to HTML.
    // Specify the HTML file names and location of external resources.
    // {0} and {1} are replaced with the current page number and resource name, respectively.
    HtmlViewOptions viewOptions = HtmlViewOptions.forExternalResources("page_{0}.html","page_{0}/resource_{0}_{1}","page_{0}/resource_{0}_{1}");
    viewer.view(viewOptions);
}

The image below demonstrates the result. External resources are placed in a separate folder.

Place HTML resources in a separate folder

Render spreadsheets as PDF

Create a PdfViewOptions class instance and pass it to the view() method to convert a spreadsheet 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.

Example 1: Convert an Excel workbook to PDF

try(Viewer viewer = new Viewer("invoice.xlsx")){
    // Convert the spreadsheet to PDF.
    PdfViewOptions viewOptions = new PdfViewOptions("output.pdf");
    viewer.view(viewOptions);
}

The following image demonstrates the result:

Render an Excel file to PDF

Example 2: Convert an Apple Numbers spreadsheet to PDF

try(Viewer viewer = new Viewer("Products.numbers")) {
    // Convert the spreadsheet to PDF.
    PdfViewOptions viewOptions = new PdfViewOptions("output.pdf");
    viewer.view(viewOptions);
}

The following image demonstrates the result:

Render an Apple Numbers spreadsheet to PDF

Render spreadsheets as PNG

Create a PngViewOptions class instance and pass it to the view() method to convert a spreadsheet file to PNG. Use the PngViewOptions.setHeight(…) and PngViewOptions.setWidth(…) properties to specify the output image size in pixels.

Example 1: Convert an Excel workbook to PNG

try (Viewer viewer = new Viewer("invoice.xlsx")) {
    // Convert the spreadsheet to PNG.
    // {0} is replaced with the current page number in the file names.
    PngViewOptions viewOptions = new PngViewOptions("output_{0}.png");
    viewOptions.setWidth(800);
    viewOptions.setHeight(900);
    viewer.view(viewOptions);
}
The following image demonstrates the result:

Render an Excel file to PNG

Example 2: Convert an Apple Numbers spreadsheet to PNG

try (Viewer viewer = new Viewer("Products.numbers")) {
    // Convert the spreadsheet to PNG.
    // {0} is replaced with the current page number in the file names.
    PngViewOptions viewOptions = new PngViewOptions("output_{0}.png");
    viewOptions.setWidth(800);
    viewOptions.setHeight(900);
    viewer.view(viewOptions);
}

The following image demonstrates the result:

Render an Apple Numbers spreadsheet to PNG

Render spreadsheets as JPEG

Create a JpgViewOptions class instance and pass it to the view() method to convert a spreadsheet file to JPEG. Use the JpgViewOptions.setHeight(…) and JpgViewOptions.setWidth(…) properties to specify the output image size in pixels.

Example 1: Convert an Excel workbook to JPEG

try (Viewer viewer = new Viewer("invoice.xlsx")) {
    // Convert the spreadsheet to JPEG.
    // {0} is replaced with the current page number in the file names.
    JpgViewOptions viewOptions = new JpgViewOptions("output_{0}.jpg");
    viewOptions.setWidth(800);
    viewOptions.setHeight(900);
    viewer.view(viewOptions);
}

Example 2: Convert an Apple Numbers spreadsheet to JPEG

try (Viewer viewer = new Viewer("Products.numbers")) {
    // Convert the spreadsheet to JPEG.
    // {0} is replaced with the current page number in the file names.
    JpgViewOptions viewOptions = new JpgViewOptions("output_{0}.jpg");
    viewOptions.setWidth(800);
    viewOptions.setHeight(900);
    viewer.view(viewOptions);
}

Detect a CSV/TSV separator

If you load a CSV/TSV file to convert it to another format, enable the SpreadsheetOptions.setDetectSeparator(…) property for a target view to automatically detect a delimiter used to separate values in the source file.

GroupDocs.Viewer can detect the following separators:

  • A comma (the default separator)
  • A semicolon
try (Viewer viewer = new Viewer("sample.csv")) {
    HtmlViewOptions viewOptions = HtmlViewOptions.forEmbeddedResources();
    viewOptions.getSpreadsheetOptions().setDetectSeparator(true);
    viewer.view(viewOptions);
}

Obtain worksheet names

GroupDocs.Viewer allows you to obtain information about the source spreadsheet file. For example, you can retrieve worksheet names, as described below:

  1. Create a ViewInfoOptions instance for a specific view.
  2. Call the Viewer.getViewInfo(…) method and pass the ViewInfoOptions instance to this method as a parameter.
  3. Use the getPages() method of the returned ViewInfo object to iterate through the list of worksheets and retrieve the worksheet names.
try (Viewer viewer = new Viewer("sample.xlsx")) {
    ViewInfoOptions viewInfoOptions = ViewInfoOptions.forHtmlView();
    // Call this method to create a single page for each worksheet.
    viewInfoOptions.setSpreadsheetOptions(SpreadsheetOptions.forOnePagePerSheet());

    ViewInfo viewInfo = viewer.getViewInfo(viewInfoOptions);

    // Print the worksheet names in the console window.
    System.out.println("The document contains the following worksheets:");
    for (Page page : viewInfo.getPages()) {
        System.out.println(" - Worksheet {page.Number}: '" + page.getName() + "'");
    }
}

The following image demonstrates a sample console output:

Retrieve worksheet names