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Downloading Files

webforJ provides methods to initiate file downloads, making it easy to deliver files to users through the browser. The Page class offers several ways to download files, whether they come from input streams, byte arrays, physical files, or resources.

Downloading files using InputStream​

The download(InputStream inputStream, String fileName) method allows you to send a file to the client using an input stream. This is particularly useful when the file content is generated dynamically or read from an external source.

InputStream inputStream = new FileInputStream("path/to/sample.pdf");
Page.getCurrent().download(inputStream, "sample.pdf");
  • inputStream: The input stream representing the file content.
  • fileName: The name under which the file will be downloaded by the client.

Downloading files using byte arrays​

The download(byte[] content, String fileName) method allows downloading files using a byte array that represents the file's content. This method is useful when file content is generated or processed in memory.

byte[] content = Files.readAllBytes(Paths.get("path/to/document.txt"));
Page.getCurrent().download(content, "document.txt");
  • content: The byte array representing the file content.
  • fileName: The name of the downloaded file.

Downloading physical files​

The download(File file, String fileName) method is used to download a file that exists on the server.

File file = new File("path/to/image.png");
Page.getCurrent().download(file, "image.png");
// In this case, the original file name will be used for the download.
Page.getCurrent().download(new File("path/to/report.pdf"));
  • file: The physical file to be downloaded.
  • fileName: The name of the file as it appears to the client.

Downloading resources​

The download(String path, String fileName) method enables downloading resources located within the app's context or specified by a path.

Page.getCurrent().download("context://resources/manual.pdf", "user-manual.pdf");
  • path: The path to a physical file or a context URL.
  • fileName: The name under which the file will be downloaded by the client.