Downloading files from internet using java

The downloaded PDF file will be stored in the specified directory, with the specified name. Downloading an image from the URL provided: Provide the URL of the image address in the above program, and give the directory, file name, and file extension to save the file on your computer.

The downloaded image will be stored in the specified directory, with the specified name. This is how you download the file from a URL. Worry not, in this article I'll explain the building blocks needed in order to automate downloading files for these kinds of tasks. Before you can create an application to download and create datasets for you, you'll need to know the basics required for automating file downloads via Java code.

Getting the basics right will help you use them to your own specific set of needs, whether it's for a backend server application or Android app. There are multiple ways to download a file using Java code. Here are just a few ways of how you can accomplish the task:.

The most easily available and a basic package available for downloading a file from internet using Java code is the Java IO package. Here we will be using the BufferedInputStream and the URL classes to open and read a file on a given address to a file on our local system.

The reason we use the BufferedInputStream class instead of the InputStream is its buffering ability that gives our code a performance boost. Before we dive deeper into the coding aspect let's take an overview of the classes and the individual functions we will be using in the process. 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. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Stack Gives Back Safety in numbers: crowdsourcing data on nefarious IP addresses.

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