Abhishek Jain:
I am using liferay DXP. I want to ask how to find the path on the file system of the server where the image gets stored using imageId . Actually I want to replace the image with a new one during image file uploading. In this case only the imageId of the previous image is known. Please help..any help would be appreciated.
Rethink this question. Where (or if) the file is on disk depends on the configured data store. It might be on disk, it might be in the database, or in S3 or in any number of other locations. Thus, there's no proper way to "replace" an image based on a file's location on disk. This is just the same answer as asking for a documentation for the database structure in order to change its content: Do not go there.
Plus, the images (in the case of images most likely only its metadata) might already be indexed.
Use the API and intercept any of the operations that change content, process the content and optionally replace it with yours.
