File io to stream instead of download a file

We will use this object in the doPost method implementation to upload file to server directory. Once the file gets uploaded successfully, we will send response to client with URL to download the file, since HTML links use GET method,we will append the parameter for file name in the URL and we can utilise the same servlet doGet method to implement file download process.

For implementing download file servlet, first we will open the InputStream for the file and use ServletContext. We will also need to set the response content length as length of the file. Once we are done with setting response configuration, we can read file content from InputStream and write it to ServletOutputStream and the flush the output to client. Check out next article in the series about Servlet Exception Handling.

Hey thank you for this tutorial. Hello Sir , Very Beatiful Example. I want to upload documents for particular user. John upload and views its documents 2. Marry upload and views its documents. This was a great tutorial. I had a few issues with the code at first, but was able to resolve. As a suggestion it would be helpful to everyone to understand that your code is probably coding in a linux based system verses windows. If coding in windows, there maybe an issue with the AbsolutePath causing an issue with saving the file to the tempfile directory on the apache server.

If using apache as the web server. Also, the code is meant to upload the file once, any subsequent uploads will result in an exception because the file already exist. So, can force remove the existing file or simply add a!

Thanks for the inputs. Nevermind this, I resolved this issue with my Intellij artifact setup. The artifact must include the external libraries.

Sorry for the trouble. Thanks for this tutorial,but when i upload the file it shows Exception in uploading file.. I had to change a few things to make this work. The biggest problem was that fileItem. I tried your code above, it works sometimes, sometimes meaning when I try downloading a 3.

What do you think? I tried your code and it store the file in tmp directory. But i need to store in server. How to save the file in url server. Just awesome topic! Its pretty easy to use. I think you can get a free trial if you ask for it.

ClassNotFoundException: com. ExpressionFactoryImpl at org. Your code is working fine but I want to upload file with same name as well as same file type. Please help me in this matter. Thanks in advance. For Ex. File Directory created to be used for storing files java.

Unknown Source at java. Unknown Source at org. My aim is to upload an encrypted file to server. So what modification should i do in this basic code? I need to select a file, do aes encryption at client side and then after encryption upload encrypted file to server. Again to retreive the file, do the decryption at client side. Posted Sep pm ganesh Add a Solution. Top Rated Most Recent. Accept Solution Reject Solution. See this one,may its useful to u.

In aspx : XML. Copy Code. Posted Sep am Murali Posted Sep am Rakesh Meel. Pdf can be downloaded in two ways in asp. Although this seem to be simple and works fine, but you need to keep in mind that this solution loads the file into your computer Memory. Therefore chances you get an exception due to insufficient memory is high when either 1 a data is too large or 2 multiple request are being made simultaneously.

Benjamin, That problem can be mitigated by using HttpClient instead. ReadToEnd ; sr. CodeChops CodeChops 1, 1 1 gold badge 20 20 silver badges 27 27 bronze badges.

Example: link but this method doesn't work, any idea is appreciated. Resonse and just used Http. Tingo Tingo 6 6 silver badges 11 11 bronze badges. I stripped Dalla's answer a bit. I'm posting my version below — Ricardo Appleton. If you are looking for a. NET Core version of Dallas's answer, use the below. Add "Content-Length", fileResp. Andreas Paulsson Andreas Paulsson 7, 3 3 gold badges 23 23 silver badges 30 30 bronze badges.

So what was missing was: Response. Oliver Fink Oliver Fink 1. Sign up or log in Sign up using Google. The java. URL class in Java is a built-in library that offers multiple methods to access and manipulate data on the internet.

In this case, we will be using the openStream function of the URL class. The method signature for the openStream function is:. The openStream function works on an object of the URL class. The URL class opens up a connection to the given URL and the openStream method returns an input stream which is used to read data from the connection.

These classes are used for reading from a file and writing to it, respectively. The contents are read as bytes and copied to a file in the local directory using the FileOutputStream. To lower the number of lines of code we can use the Files class available from Java 7. The Files class contains methods that read all the bytes at once and then copies it into another file.

Here is how you can use it:. Java NIO is an alternative package to handle networking and input-output operations in Java. The main advantage that the Java NIO package offers is that it's non-blocking, and has channeling and buffering capabilities.

When we use the Java IO library we work with streams that read data byte by byte. The specified path can also refer to a relative path or a Universal Naming Convention UNC path for a server and share name.

For example, all the following are acceptable paths:. Appends lines to a file, and then closes the file. If the specified file does not exist, this method creates a file, writes the specified lines to the file, and then closes the file.

Appends lines to a file by using a specified encoding, and then closes the file. Asynchronously appends lines to a file, and then closes the file. Asynchronously appends lines to a file by using a specified encoding, and then closes the file. Opens a file, appends the specified string to the file, and then closes the file. If the file does not exist, this method creates a file, writes the specified string to the file, then closes the file.

Appends the specified string to the file using the specified encoding, creating the file if it does not already exist. Asynchronously opens a file or creates a file if it does not already exist, appends the specified string to the file, and then closes the file.

Asynchronously opens a file or creates the file if it does not already exist, appends the specified string to the file using the specified encoding, and then closes the file. Creates a StreamWriter that appends UTF-8 encoded text to an existing file, or to a new file if the specified file does not exist. Creates or overwrites a file in the specified path, specifying a buffer size and options that describe how to create or overwrite the file.

Creates or overwrites a file in the specified path, specifying a buffer size, options that describe how to create or overwrite the file, and a value that determines the access control and audit security for the file. Creates a file symbolic link identified by path that points to pathToTarget. Creates or opens a file for writing UTF-8 encoded text. If the file already exists, its contents are overwritten.

Decrypts a file that was encrypted by the current account using the Encrypt String method. Gets a FileSecurity object that encapsulates the access control list ACL entries for a specified file.

Gets a FileSecurity object that encapsulates the specified type of access control list ACL entries for a particular file. Gets the FileAttributes of the file on the path. Returns the creation date and time, in coordinated universal time UTC , of the specified file or directory.

Returns the date and time, in coordinated universal time UTC , that the specified file or directory was last accessed. Returns the date and time, in coordinated universal time UTC , that the specified file or directory was last written to. Moves a specified file to a new location, providing the options to specify a new file name and to overwrite the destination file if it already exists. Opens a FileStream on the specified path, with the specified mode and access with no sharing.

Asynchronously opens a binary file, reads the contents of the file into a byte array, and then closes the file.