Download file java code

Primary Primary. Skip to content. This post will discuss how to download a file from a URL in Java. Using FileChannel. FileOutputStream ;. IOException ;. InputStream ;. URL ;. Channels ;. ReadableByteChannel ;. Files ;. Paths ;. July 25, at pm. Ravi says:. June 4, at am. Gaurab Pradhan says:. January 15, at am. Tran Tuan says:. October 9, at am. Leave a Reply Cancel reply Your email address will not be published. Leave this field empty. Exact matches only. Search in title. Search in content. Find centralized, trusted content and collaborate around the technologies you use most.

Connect and share knowledge within a single location that is structured and easy to search. I need a java code for downloading files from the internet.. For example I want to download doc,pdf files from the internet means i have to do it through my code.. So can anyone help me. It's easiest if you use Apache Commons IO :. Otherwise, you have to write a loop and use a byte array as buffer, which can be a bit tricky to get exactly right.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Java code for downloading files Ask Question. 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. However, the Java NIO package uses channels and buffers. The buffering and channeling capabilities allow the system to copy contents from a URL directly into the intended file without needing to save the bytes in application memory, which would be an intermediary step.

The ability to work with channels boosts performance. The downloaded contents will be transferred to a file on the local system via the corresponding file channel. After defining the file channel we will use the transferFrom method to copy the contents read from the readChannel object to the file destination using the writeChannel object.