How to build a Java 8 stream from / System.console()?

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Given a file, we can transform it into a stream of strings using, e.g.,

Stream<String> lines = Files.lines(Paths.get("input.txt"))

Can we build a stream of lines from the standard input in a similar way?

A compilation of kocko's answer and Holger's comment:

BufferedReader in = new BufferedReader(new InputStreamReader(;
Stream<String> stream = in.lines().limit(numberOfLinesToBeRead);

Java Read Console Input, Reading console input in programs may be necessary to make applications To read console input, we shall wrap the (standard input stream) in an� The class provides methods to access the character-based console device, if any, associated with the current Java virtual machine. The Console class was added to by JDK 6. Important Points: It is used to read from and write to the console, if one exists.

you can use just Scanner in combination with Stream::generate:

Scanner in = new Scanner(;
List<String> input = Stream.generate(in::next)

or (to avoid NoSuchElementException if user terminates before limit is reached):

Iterable<String> it = () -> new Scanner(;

List<String> input =, false)

Console (Java Platform SE 8 ), How to build a Java 8 stream from / System.console()?. 由怎甘沉沦 提交于2019-11-30 11:49:00. Given a file, we can transform it into a stream of� 3- System.console. This is the modern way of reading input from console in Java, it’s introduced in JDK 1.6 and allows developers to read input without using The drawback of using this technique is that it doesn’t work under IDE and only works in interactive environments.

Usually the standard input is read line by line, so what you can do is store all the read line into a collection, and then create a Stream that operates on it.

For example:

List<String> allReadLines = new ArrayList<String>();

BufferedReader in = new BufferedReader(new InputStreamReader(;
String s;
while ((s = in.readLine()) != null && s.length() != 0) {

Stream<String> stream =;

Java, System.out, and System.error, Console cons; char[] passwd; if ((cons = System.console()) != null && (passwd = cons. Writes a formatted string to this console's output stream using the specified An invocation of this method of the form con.printf(format, args) behaves in� The "standard" output stream. This stream is already open and ready to accept output data. Typically this stream corresponds to display output or another output destination specified by the host environment or user. For simple stand-alone Java applications, a typical way to write a line of output data is: System.out.println(data)

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Read and Write User Input in Java, A FileInputStream obtains input bytes from a file in a file system. FileOutputStream. A file output stream is an output stream for writing data to a File or to a� 3. Java Read Console Input using Scanner. In Java, represents the stanadard input. By deafult, it is system console. The Scanner class, when reading from the console, provides methods to read different types of data e.g. integers, numbers, strings, etc. Method, Finally, we'll see how to use the Console class, available since Java 6, for both console input and output. We can also use the next() method to get the next input token from the stream: hasNext(Pattern.compile(""))) { For console output, we can use System.out — an instance of the� Inventory Management System in Java part 1 - Duration: 18:55. Tutus Funny 16,274 views. 18:55. C# Step By Step Make Stock Management Software Part 1 - Duration: 1:17:24.

  • See also…
  • This throws a NoSuchElementException if the stream ends before the limit (e.g. with Ctrl/Cmd+D).
  • @AjahnCharles fixed
  • If you have a BufferedReader there is no need for storing the lines into a Collection to get a Stream. The bigger problem is that interactive consoles usually don’t have an end-of-file…
  • Nice one. Didn't know this newly introduces method. Thanks, @Holger. :)
  • Great, BufferedReader.lines will eliminate much of the verbosity in this answer. If the numer of lines to be read is known, then in.limit(numberOfLines) should work here
  • "interactive consoles usually don’t have an end-of-file…" Don't you get an end-of-file when the program terminates? :-P
  • @Lii: no, a terminated program will not receive an end-of-file as a terminated program can’t receive anything.