Download file from database using java

View All. Mudita Rathore Updated date Jan 29, Introduction This article explains how to upload files in the database and download files from the database in the ASP. The procedure for creating the application is as in the following. Step 1 First we create a database in SQL. Open SQL Server Select "New Query" and create the database and table.

But it is displaying only a blank pdf document. File; import java. FileOutputStream; import java. FileReader; import java. InputStream; import java. OutputStream; import java. Blob; import java. Connection; import java. DriverManager; import java. ResultSet; import java. 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.

The getContent function returns an InputStream object that can be further used with a BufferedInputStreamReader to enhance performance. Now all you need to do is read from the stream byte by byte and write the contents into a file using the FileOutputStream class. The last thing required to be done is closing all the open resources in order to ensure that the system resources are not overutilized and that there are no memory leaks.

So there you have it - these are the simplest ways to download a file using the basic Java code and other third party libraries. Can you please share an example code of how to build a spring web application to upload any excel file, contents of which we do not know in advance?

How can we create an entity with no certain primary key, column names, etc.? First of all, greetings from Brazil and thank you so much for this tutorial.

Well, in my case, in the controller, the length of List of files was returning a integer. Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website.

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