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Java download large files

Java download large files
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How to download and save a file from Internet using Java? - Stack Overflow


Aug 21,  · There are multiple ways to download a file using Java code. Here are just a few ways of how you can accomplish the task: Java IO. The most easily available and a basic package available for downloading a file from internet using Java code is the Java IO package. I know there are several methods for grabbing and reading online files (URLs) line-by-line, but is there a way to just download and save the file using Java? java download. share | improve this question. edited Aug 28 '13 at How to read a large text file line by line using Java? How to download a file with blogger.com (without using. May 25,  · We want the files to be available via HTTP (some users are going to be behind firewalls that aren't going to allow FTP, Bittorrent, etc.). The will be a library of files the end user could download, so we aren't talking about a one time large download. The will be download different large files on a semi-regular basis.




java download large files


Java download large files


It was what I learned first, java download large files, it confounded then delighted me after I started to get the hang of it, and it made a heck of a lot more sense to me than Java, with its compilation, its need to declare every single variable type yes, I know the latest versions of Java have done away with this requirement for some of the simpler inferencesand its massive libraries of maps, lists, collections, etc, java download large files.


That being said, I do make an effort to get better at Java and the other shortcomings I have by not having a traditional computer science degree.


I stared at him as the wheels began to turn in my head, and I accepted the challenge to find an optimal solution in Java, as well. So before I get down to how I solved my challenge using Java, let me actually recap the requirements. As I said in my original articleon using Node. The challenge was straightforward enough: download this large zip file of text from the Federal Elections Commission, read that data out of the.


Note: I add the asterisk after the file link because others who have chosen to undertake this challenge themselves have actually seen the file size increase since I downloaded it back in the beginning of October of At last count, someone mentioned it was up to 3.


I believe the solutions I present below will still work though, but your counts and numbers will vary from mine. I liked the challenge and wanted some practice manipulating files, so I decided to see if I could figure it out. Some methods are baked straight into the core Java framework, and some are still independent libraries that need to be imported and bundled together to run, java download large files.


But regardless, I came up with three different methods to read files in Java, java download large files, and then I performance tested them to see which methods were more efficient. I did this so that I could have a more accurate idea of how the different methods stacked up against each other for the performance part of my evaluation.


Apples to apples comparisons and all that. In essence, FileInputStream just opens the connection to the file to be read, be it images, characters, etc. Another option at least for my case is to use FileReader which is specifically for reading streams of characters, but I went with FileInputStream for this particular scenario.


I used FileReader in another solution I tested later on. Once the connection to the file is established, Scanner comes into play to actually parse the text bytes into strings of readable data. Scanner breaks its inputs into tokens using a delimiter pattern, which by default matches whitespace but can also be overridden to use regex or other values. Then, by using the Scanner. And here is my full code to solve all the tasks set out above. Getting the line java download large files for the entire file was easy, java download large files.


Request 1: done. I had to add 1 to each index to get the correct name position java download large files the array because I incremented my line count starting at 0 as soon as Scanner. After Scanner. Trust me, I triple checked this to make sure I was doing my math correctly. I used an ArrayList for the names because it maintains the elements insertion order which means while displaying ArrayList elements the result set will always have the same order in which the elements got inserted into the List.


As I approached the donation counting request, I wanted to do more than count donations by month, I wanted to count them by both month and year, as I had donations from both and Then, I took the 5th element in each line, the raw date, java download large files used the substring method to pull out just the month and year for each donation.


I reformatted each date into easier-to-read dates and added them to the new dates ArrayList. The date results were not sorted in any particular order, but they could be by transforming the HashMap back in to an ArrayList or LinkedList, if need be, java download large files.


I chose not to though, because it was not a requirement. The fourth request, java download large files, to get all the first names only and find the count of the most commonly occurring one, was trickiest.


It required me to first, check if the names array contained a comma there were some business names that had no commasthen split the name on the comma and trim any extraneous white space from it. See the code snippet below. If the name already existed in the HashMap, the value was incremented by 1. Once we have the HashMap, which is unordered by nature, it needs to be sorted from largest to smallest value to get the most commonly occurring first name, so I transform each entry in the HashMap into a LinkedList, which can be ordered and iterated through, java download large files.


And finally, the list is sorted using the Collections. Check this out. Once all of that has been done, the first key value pair of the LinkedList can finally be pulled out and displayed to the user. Request 4 and arguably the most complicated of all the tasks : done. Because the logic portion of the code is exactly the same. BufferedReader reads text from a character-input stream, buffering characters so as to provide for the efficient reading of characters, java download large files, arrays, and lines, and it is wrapped around the FileReader method, which is the actual method reading the specified text file.


And here is my full code using BufferedReader and FileReader. The last solution I came up with involves a library made by Apache, called FileUtils. I used Gradle for my Java project, so all I had to do was include the commons-io library in my build. The LineIterator, does exactly what its name suggests: it holds a reference to an open Reader like FileReader in my last solutionand iterates over each line in the file.


LineIterator once the dependency library has been included. And here is my full code using FileUtils. A fat jar also known as an uber jar is a self-sufficient archive which contains both classes and dependencies needed to run an application.


It makes the project unnecessarily heavy. There are plugins available now, but I just wanted a quick and easy way to bundle my one dependency up with my JAR. So I modified the jar task from the Java Gradle plugin. By default, this task produces jars without any dependencies. I can overwrite this behavior by adding a few lines of java download large files. I just need two things to make it work:. Thanks to Baeldung for the help on making this fat JAR. Once the main class file has been defined and in my demo repoI made three main class files, which confused my IDE to no end and the dependencies were included, you can run the.


And your program should run with the LineIterator library included. Great, now I have three different ways to read and process large text files in Java, my next mission: figure out which way is more performant. For java download large files testing my different Java applications and the functions inside them, I came across java download large files handy, ready-made functions in Java 8: Instant. What I wanted to do was see if there was any measurable differences between the different java download large files of reading the same file.


So besides the different file read options: FileInputStream, BufferedReader and LineIterator, I tried to keep the code and timestamps marking the start and stop of each function as similar as possible. And I think it worked out pretty well. And that timing can be converted to all sorts of different, readable formats: milliseconds, seconds, java download large files, hours, java download large files, etc. This one is timing how long it takes to get the line count of the total file.


I ran all three of my solutions against the 2. BufferedReader is nice because it requires no extra dependencies, but it is slightly more complex to set up in the beginning, with the FileReader to wrap inside. Whereas LineIterator is an external library but it makes iterating over the file extra easy after it is included as a dependency. The percentage improvements are included at the end of the table above as well, for reference.


FileInputStreamin an interesting twist, got blown out of the water by the other two. Below are the raw screenshots from my terminal for each of my solutions. Solution 1: FileInputStream. Solution 2: BufferedReader. Solution 3: FileUtils. In the end, buffered streams and custom file read libraries are the most efficient ways processing large data sets in Java.


At least, for the large text files I was tasked with reading. Thanks for reading my post on using Java to read really, really large files. Thanks for reading, I hope this gives you an idea of how to handle large amounts of data with Java efficiently and performance test your solutions. Claps and shares are very much appreciated!


If you enjoyed reading this, you may also enjoy some of my other blogs:. References and Further Resources:. Sign in. Paige Niedringhaus Follow. Task 3: Count How Many Donations Occurred in Each Month As I approached the donation counting request, I wanted to do more than count donations by month, I wanted to count them by both month and year, as I had donations from both and LineIterator Implementation.


I just need two things to make it work: a Main-Class attribute in the manifest file check, I had three main class files in my demo repo for testing purposes and any dependencies jars Thanks to Baeldung for the help on making this fat JAR.


Thanks to Kiarash Irandoust. Senior Software Engineer, previously a digital marketer. See responses 9. More From Medium. Discover Medium. Make Medium yours. Become a member. About Help Legal.


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Java download large files


java download large files

Jan 04,  · In the end, buffered streams and custom file read libraries are the most efficient ways processing large data sets in Java. At least, for the large text files I was tasked with reading. Thanks for reading my post on using Java to read really, really large blogger.com: Paige Niedringhaus. Jul 18,  · Related Java File Download Tutorials: Java Servlet Download File Example; Spring MVC File Download Example; Struts File Download Example; Java Swing application to download files from HTTP server with progress bar; Java FTP file download tutorial and example. Other Java network tutorials: How to use Java URLConnection and HttpURLConnection. Java software for your computer, or the Java Runtime Environment, is also referred to as the Java Runtime, Runtime Environment, Runtime, JRE, Java Virtual Machine, Virtual Machine, Java VM, JVM, VM, Java plug-in, Java plugin, Java add-on or Java download.






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