How to download java files

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. The transferFrom and transferTo methods are much more efficient than working with streams using a buffer.

The transfer methods enable us to directly copy the contents of the file system cache to the file on the system. Thus direct channeling restricts the number of context switches required and enhances the overall code performance.

Now, in the following sections, we will be looking at ways to download files from a URL using third-party libraries instead of core Java functionality components. Now you may be thinking why would we use this when Java has its own set of libraries to handle IO operations. However, Apache Commons IO overcomes the problem of code rewriting and helps avoid writing boilerplate code.

In order to start using the Apache Commons IO library, you will need to download the jar files from the official website. When you are done downloading the jar files, you need to add them to use them. If you are using an Integrated Development Environment IDE such as Eclipse , you will need to add the files to the build path of your project.

There is only a single line of code required to download a file, which looks like:. The connection and read timeouts convey the permissible time for which either the connection may stay idle or reading from the URL may stop. We will use the copy inputStream, fileOS method to download a file into the local system. Check out our hands-on, practical guide to learning Git, with best-practices, industry-accepted standards, and included cheat sheet.

Stop Googling Git commands and actually learn it! The function returns the number of bytes copied. 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 latest version of JDK is We can download and install multiple versions of JDK in a system.

But we recommend you to install the latest version only. In this section, we will learn how to download and install the latest version of Java. In this section, we are going to download the Java SE.

Follow the steps given below to download the JDK. Step 3: Click on the JDK download link according to your operating system. In our case, we are using Windows operating system, so we are clicking on the jdk It downloads the. Step 4: Check the box to accept the License Agreement. It activates the download button. Step 5: Click on the Download jdk It starts downloading the JDK Step 6: Double click on the downloaded. It asks for changes on your computer.

Click on the Yes button to run the setup. Step 8: Click on the Change button if you want to change the installation directory. Otherwise, click on the Next button.

It starts the installation of JDK. Click on the Close button. We have installed Java successfully. To check the Java is successfully installed or not, follow the steps given below.

Step Go to the bin folder of the JDK and copy the path. Step Open the Command Prompt and type the following commands:. In the code, we have a URL object fetchWebsite that points to the source of the file. We create an object of Path that tells the target where we want the file to be copied.

Next, we open a stream to get the bytes from the online resource and pass the inputSteam to copy. As it takes three arguments, the first and second are the inputStream and path objects, while the third specifies the CopyOption or the way the copy operation should be performed. We use StandardCopyOption. Download a File Using the java.

FileOutputStream; import java. IOException; import java. URL; import java. Channels; import java.