--- layout: default-layout title: DirectoryFetcher - Dynamsoft Capture Vision Android Edition API Reference description: The class DirectoryFetcher of Dynamsoft Capture Vision Android is a utility class that retrieves a list of files from a specified directory based on certain criteria. keywords: directory fetcher, Java, Kotlin needGenerateH3Content: true needAutoGenerateSidebar: true noTitleIndex: true --- # DirectoryFetcher The `DirectoryFetcher` class is a utility class that retrieves a list of files from a specified directory based on certain criteria. It inherits the [`ProactiveImageSourceAdapter`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html) class so that you can set it as the input of `CaptureVisionRouter` with the API [`setInput`]({{ site.dcv_android_api }}capture-vision-router/multiple-file-processing.html#setinput). ## Definition *Namespace:* com.dynamsoft.utility *Assembly:* DynamsoftCaptureVisionBundle.aar ```java class DirectoryFetcher extends ProactiveImageSourceAdapter ``` ## Methods | Method | Description | | ------ | ----------- | | [`setDirectory`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setdirectory) | Sets the directory path and filter for the file search. | | [`setPages`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setpages) | Set the pages to read. | | [`DirectoryFetcher`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#directoryfetcher-1) | The constructor. | The following methods are inherited from [`ProactiveImageSourceAdapter`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html). | Method | Description | | ------ | ----------- | | [`setImageFetchInterval`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setimagefetchinterval) | Sets the time interval for the ImageSource to wait before attempting to fetch another image to put in the buffer. | | [`getImageFetchInterval`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getimagefetchinterval) | Gets the time interval for the ImageSource to wait before attempting to fetch another image to put in the buffer. | The following methods are inherited from [`ImageSourceAdapter`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html). | Method | Description | | ------ | ----------- | | [`addImageToBuffer`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#addimagetobuffer) | Adds an image to the internal buffer. | | [`clearBuffer`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#clearbuffer) | Clears all images from the buffer, resetting the state for new image fetching. | | [`getBufferOverflowProtectionMode`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getbufferoverflowprotectionmode) | Get the current mode for handling buffer overflow. | | [`getColourChannelUsageType`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getcolourchannelusagetype) | Get the current usage type for color channels in images. | | [`getImageCount`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getimagecount) | Get the current number of images in the buffer. | | [`getImage`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getimage) | Get a buffered image. Implementing classes should return a Promise that resolves with an instance of `DSImageData`. | | [`getMaxImageCount`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getmaximagecount) | Get the maximum number of images that can be buffered. | | [`hasImage`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#hasimage) | Checks if an image with the specified ID is present in the buffer. | | [`hasNextImageToFetch`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#hasnextimagetofetch) | Determines whether there are more images available to fetch. | | [`isBufferEmpty`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#isbufferempty) | Determines whether the buffer is currently empty. | | [`setBufferOverflowProtectionMode`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setbufferoverflowprotectionmode) | Sets the behavior for handling new incoming images when the buffer is full. | | [`setColourChannelUsageType`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setcolourchannelusagetype) | Sets the usage type for color channels in images. | | [`setErrorListener`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#seterrorlistener) | Sets an error listener to receive notifications about errors that occur during image source operations. | | [`setMaxImageCount`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setmaximagecount) | Sets the maximum number of images that can be buffered at any time. | | [`setNextImageToReturn(imageId)`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setnextimagetoreturnimageid) | Sets the processing priority of a specific image. This can affect the order in which images are returned by getImage. | | [`setNextImageToReturn(imageId,keepInBuffer)`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setnextimagetoreturnimageidkeepinbuffer) | Sets the processing priority of a specific image. This can affect the order in which images are returned by getImage. | | [`startFetching`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#startfetching) | Start fetching images from the source to the Video Buffer of ImageSourceAdapter. | | [`stopFetching`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#stopfetching) | Stop fetching images from the source to the Video Buffer of ImageSourceAdapter. | ### setDirectory Sets the directory path and filter for the file search. ```java void setDirectory(String directoryPath, String filter, boolean recursive) throws UtilityException; ``` **Parameters** `[in] directoryPath`: The directory path. `[in] filter`: A string that specifies file extensions. It determines which kinds of files to read. e.g "\*.BMP;\*.JPG;\*.GIF". `[in] recursive`: Specifies whether to load files recursively. **Exception** | Error Code | Value | Description | | :--------- | :---- | :---------- | | EC_READ_DIRECTORY_FAILED | -10064 | Failed to read the directory. | ### setPages Set the pages to read. ```java void setPages(int[] pages) throws UtilityException; ``` **Parameters** `pages`: An array that contains all the pages to read. **Exception** | Error Code | Value | Description | | :--------- | :---- | :---------- | | EC_FILE_NOT_FOUND | -10005 | File not found. | | EC_FILE_TYPE_NOT_SUPPORTED | -10006 | The file type is not supported. | | EC_IMAGE_READ_FAILED | -10012 | Failed to read the image. | ### DirectoryFetcher The constructor. ```java DirectoryFetcher() ``` ## Inherited Methods The following methods are inherited from the [`ImageSourceAdapter`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html) class: | Method | Description | | ------ | ----------- | | [`hasNextImageToFetch`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#hasnextimagetofetch) | Determines whether there are more images left to fetch. | | [`setMaxImageCount`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setmaximagecount) | Set the maximum capability of the Video Buffer. | | [`getMaxImageCount`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getmaximagecount) | Get the property defines the maximum capability of the Video Buffer. | | [`setBufferOverflowProtectionMode`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setbufferoverflowprotectionmode) | Sets a mode that determines the action to take when there is a new incoming image and the buffer is full. You can either block the Video Buffer or push out the oldest image and append a new one. | | [`getBufferOverflowProtectionMode`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getbufferoverflowprotectionmode) | Get the buffer overflow protection mode. | | [`getImageCount`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getimagecount) | Get the current image count in the Video Buffer. | | [`isBufferEmpty`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#isbufferempty) | Check whether the Video Buffer is empty. | | [`setColourChannelUsageType`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setcolourchannelusagetype) | Set the usage type of a color channel in an image. | | [`getColourChannelUsageType`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getcolourchannelusagetype) | Get the usage type of a color channel in an image. | | [`startFetching`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#startfetching) | Start fetching images from the source to the Video Buffer of ImageSourceAdapter. | | [`stopFetching`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#stopfetching) | Stop fetching images from the source to the Video Buffer of ImageSourceAdapter. | | [`getImage`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#getimage) | Get an image from the Video Buffer. | | [`setNextImageToReturn(imageId)`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setnextimagetoreturnimageid) | Specify the next image that is returned by method getImage. | | [`setNextImageToReturn(imageId,keepInBuffer)`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#setnextimagetoreturnimageidkeepinbuffer) | Specify the next image that is returned by method getImage. | | [`hasImage`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#hasimage) | Check the availability of the specified image. | | [`addImageToBuffer`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#addimagetobuffer) | Adds an image to the buffer of the adapter. | | [`clearBuffer`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#clearbuffer) | Clears the image buffer. | | [`setErrorListener`]({{ site.dcv_android_api }}core/basic-structures/image-source-adapter.html#seterrorlistener) | Clears the image buffer. |