Java download error get file specified

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. 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. After installing the JRE, run the following test to verify the version of Java that is recognized by the system. On the keyboard, press the Win Windows key and the R key simultaneously to open the Run box. Alternatively, you can select Start , then Run.

In the Run box, type cmd to run the Windows command console. Click the Advanced tab, and then click Environment Variables. The system cannot find the file specified in java Ask Question. Asked 9 years, 4 months ago. Active 1 year, 7 months ago. Viewed k times. I am making a program that opens and reads a file.

This is my code: import java. Improve this question. Please don't use DataInputStream if you want to read text, its more confusing than useful. Add a comment. Active Oldest Votes. Improve this answer. Fouad Eng. Fouad k 65 65 gold badges silver badges bronze badges. This is late but why do we need a. This answer is helpful to debug the issue and find root cause actually. I have copied your code and it runs fine. Adrian Shum Adrian Shum 36k 9 9 gold badges 77 77 silver badges bronze badges.