To get full access to the Kademi Hub existing customers can login here, or new customers can register here.
Fluent builder for generating a thumbnail from an uploaded image or PDF and saving it into content storage. Obtained by calling newThumbnailBuilder on the owning image manager, configured with the source stream, content type, target dimensions and output location, then executed by calling build. The generated thumbnail is always written as a PNG file.
Group: Builders
Methods
withSourceInputStream(InputStream inputStream)
Returns: ThumbnailBuilder
Sets the stream to read the source image or PDF from. The stream is closed by build.
| Parameter | Description |
|---|---|
inputStream | the stream containing the source image or PDF |
withContentType(String contentType)
Returns: ThumbnailBuilder
Sets the content type of the source, which selects how it is processed. Any type containing "image" is scaled as an image, and "application/pdf" has its first page rendered; anything else is rejected by build.
| Parameter | Description |
|---|---|
contentType | the source's content type, for example "image/png" or "application/pdf" |
withHeight(int height)
Returns: ThumbnailBuilder
Sets the height in pixels of the generated thumbnail. Used for image sources only; PDF sources are rendered at a quarter of the given width and ignore the height.
| Parameter | Description |
|---|---|
height | the thumbnail height in pixels |
withWidth(int width)
Returns: ThumbnailBuilder
Sets the width in pixels of the generated thumbnail. For a PDF source the page is rendered at a quarter of this width.
| Parameter | Description |
|---|---|
width | the thumbnail width in pixels |
withOutputDir(String outputDir)
Returns: ThumbnailBuilder
Sets the content storage directory the generated thumbnail is written into. Required; build rejects the call if it has not been set.
| Parameter | Description |
|---|---|
outputDir | the content storage directory path to store the thumbnail under |
withOutputFileName(String outputFileName)
Returns: ThumbnailBuilder
Sets the file name the generated thumbnail is stored under within the output directory. The content is always PNG, so give it a .png extension.
| Parameter | Description |
|---|---|
outputFileName | the file name to store the thumbnail as |
build()
Returns: void
Generates the thumbnail from the configured source and stores it at the configured output directory and file name. An image source is scaled to the configured width and height; a PDF source has its first page rendered at a quarter of the configured width. The output is always written as PNG. This does image decoding and content storage writes, so it is expensive.
© 2025 Kademi Ltd