Predefined stream object attached to the standard input in Java console applications.
It's a static variable in Java's System class. This tag is intended for questions about Java applications that read from the standard input.
Questions tagged [system.in]
191 questions
1
vote
1 answer
How does the JAVA Scanner class work internally?
In JAVA when you import the Scanner class and create a Scanner object, how does the underlying logic work to capture the input and write it onto memory? I understand that the following statement
Scanner sc = new Scanner (System.in)
means you are…
mrarvind901
- 11
- 1
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1
vote
1 answer
Can't get Gradle to use System.in
This question explains how to use System.in when running a task to run a specific class in a project.
But for me currently it's not working: although I have included the application plugin and the following lines in build.gradle:
mainClassName =…
mike rodent
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1
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1 answer
java writing letters in console before user input
I am writing simple socket chat using console to output messages. The problem is that when one user types a message, and at the same time getting one, his input interrupted:
I: writing my input here, but
Other_user: hi! here is a message for you.
I:…
Worm359
- 87
- 12
1
vote
0 answers
File I/O Redirect System.in fails while Normal file read with given path works properly
I am reading a PCAP file byte by byte in Java using IO-Redirection System.in.
It does not reads the bytes in correct manner.
I am using
System.in.read(byte[], int off, int len);
When I do the same thing with
InputStream is = new…
Abhijit
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1
vote
2 answers
Java do-while loop skipping console input
class Noob1 {
public static void main(String args[])
throws java.io.IOException{
char ch, answer;
answer = 'g';
do {
System.out.println("Guess from A-L:");
ch = (char) System.in.read();
…
naike
- 11
- 3
1
vote
1 answer
Can java system.in work together with input source code at same time without using thread
Saying my requirement is:
Either user type something in console (from system.in) or socket receive something, proceed to next step.
So I have a scanner
Scanner sc = new Scanner(System.in);
Have an Udp client. (a different input…
TTTTTAAOOOO
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- 6
1
vote
2 answers
Getting null value from bufferedreader
I am not able to understand why I am getting null from bufferedreader in following code (2nd line of output), while it worked fine at some places (1st line of output).
I have used several system.out.println's just for debugging purpose.
Although the…
Flying disk
- 120
- 7
1
vote
3 answers
Clear Scanner(in)
on my code, I've a long loop of sequential operation.
I make a thread to stop this loop manually.
Basically
private static void sendAndCheck() throws InterruptedException {
stop = false;
StopChecker r = new StopChecker();
…
Lele
- 703
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1
vote
0 answers
Java: How to use System.in Several times in one program?
On my previous question I've learned that I shouldn't close the System.in, and I also learned that using multiple Scanner together can cause problems.
The problem is that I need some methods recursively to use the Scanner to scan some inputs from…
Harout Tatarian
- 431
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1
vote
2 answers
Why does System.in.read() wait till the user presses enter?
System.in.read() is used to read a single character.
Then why does it allow the user to enter as many characters as he can until he presses enter?
Why doesn't it stop as soon as he presses a key and returns the character?
char ch =…
Uma Kanth
- 5,659
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1
vote
1 answer
Common way to use System.in several times without closing
I have a console menu that has to read inputs a few times in different methods. I use a new BufferedReader(new InputStreamReader(System.in)) to do that. But if this reader is closed in a method it's not useable/openable again because of…
cmtjk
- 359
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- 12
1
vote
1 answer
"input line is too long" when entering string in Java console
When I input a string of 4500 characters followed by a newline feed in Java console, it displays input line is too long runtime error in the terminal.
I have tried using both Scanner and BufferedReader, but no success.
user4392919
1
vote
2 answers
Java Scanner while loop
I'm trying to take in a string input which consists of multiple lines of numbers separated by ',' and ';' .
Example:
1,2;3,4;5,6;
9,8;7,6;
0,1;
;
Code:
ArrayList alist = new ArrayList<>();
String delims = ";|\\,";
int i =…
fralewsmi
- 92
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- 12
1
vote
3 answers
After getting user input "Scanner name = new Scanner(System.in);" how to use is in a if statement?
So im learning java,bit by bit im getting a bit more knowledge, now im following tutroials and other webistes ect on learning but im stuck on one problem where i can't figure out what's the problem.
import java.util.Scanner;
class apples{
…
Charles Florianowicz
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1
vote
1 answer
How come when i read an in from System.in I get a completely different value than I read in?
Here's the code:
public static void main(String args[]) throws IOException {
int i = System.in.read();
System.out.println(i);
}
When I input 13 for example it prints out 49..? why is that? And how do I fix that?
user3011240
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