Under Manage public permissions, select Grant public read access to this bucket. Give your bucket whatever name you want (I’m calling mine my-uploaded-files for now.)Ĭlick the Next button twice to set the permissions on the bucket. Login to the AWS S3 console and then click the Create bucket button. You can organize your files into different buckets, and buckets can contain subdirectories that then contain files. S3 uses the idea of buckets, which are a little bit like directories. It lets you store your files in Amazon’s cloud, and it offers a Java library that makes uploading to S3 pretty easy. AWS S3Īmazon Simple Storage Service (aka AWS S3) is a file hosting service offered by Amazon. Instead, the general approach is to store the file itself in a file hosting provider, and then store the URL of that file in a database. Note that it’s also possible to store your files directly in a database, but that’s generally not a great idea.

The file host then gives us a URL for the file that we can use in our HTML. When the user uploads a file, we get that file in memory on our server, and we then upload it to the file host. Using a file hosting provider allows us to store all of our files separately from the server running our code. Instead of storing the files on the server or in the web app directory, in real life we probably want to use a file hosting provider. And if we’re using a server host like Elastic Beanstalk or App Engine, we might not even be allowed to store files on our server, which are usually supposed to be as lightweight as possible. First, all of the files will be deleted whenever we make a change to our code and redeploy the server. The above examples store the uploaded file directly in the server directory, which is a bad idea for a few reasons.

See here for a discussion on this approach, but basically: find a library that does this for you! File Hosting If we want to prevent cases like that, then we have to examine the contents of the uploaded file to make sure it contains an allowed type. So we’re still not stopping a user from, for example, creating a. Note that this only checks the filename of the file, not its actual content. If the user tries to upload a file that ends with something other than. png, and if so, it goes through with the upload and creates HTML that contains an tag that points to the URL of the uploaded image file: This code now checks whether the original name of the file ended with. Import java.io.File import java.io.IOException import java.io.InputStream import import import import import import import public class FileUploadServlet extends HttpServlet

Html file upload example code