Java downloading a file

No spam ever, unsubscribe at any time. How to download and save a file from Internet in Java. You might also like IOException; import java. URL; import java. Channels; import java. We use the following code to include the dependency in the project. FileUtils; import java.

File; import java. InputStream; import java. Files; import java. I am working on a requirement that should allow the user select a source folder and then upload only the jpeg files in that folder to a server location. Please provide some input on how a folder selection can be implemented instead of a file.

Hey, thanks for the Tutorial. Hi Juan, Please check upload. See if you can add the your file extension in the allowed list and that should appear. It worked! How do i change it, that i can upload any file not just. Thank you. Hi Andi, Glad you found it useful. To allow more extensions you need to change upload. If the value of the variable i is -1, then it indicates that the contents of the file are over 2GB.

When the returned value is -1, you can use the function copyLarge inputStream, fileOS in place of the copy inputstream, fileOS function to handle this load. Both of these functions buffer the inputstream internally. The internal buffer means we do not have to use the BufferedInputStream class to enhance our code performance and helps us avoid writing boilerplate code.

Another library managed by the Apache organization is the HttpComponents package. This library uses the request-response mechanism to download the file from a given URL. The first step to downloading a file is to create an HTTP client object that would issue the request to the server.

For this, we will be using the CloseableHttpClient class. The code snippet that creates a new HTTP client is as follows:. We then need to create an HttpGet or HttpPost object to send the request to the server.

The request is created by the following line of code:. The execute request function is applied to the client object and returns with a response from the server. Once the request is sent to the server we need a response object to receive the data sent from the server. To catch the response from the server we use the HttpResponse class object. The data sent by the server in the form of a message is obtained through the getEntity function. You can also obtain the response code sent by the server through the response object and use it to your specific need.

The data to be downloaded is encapsulated within the entity object and can be extracted using the getContent function.