Scanner class throws java.util.NoSuchElementException: No line found abnormal

 This post last edited by the using_name on 2014-05-15 20:22:59

  class   exception   java   Scanner   No line found

scanner object read an entire line of information in different places in the program , each after use very natural too close to call a method to switch off , when the second scanner object calls nextLine appears NoSuchElementException: No line found exception.
object if the first one does not turn off the scanner , you will not complain. Want to know why.
personally think that this is all of us will often make the mistake , but the Internet can not find an explanation. I hope the great God appear.
simplify the code shown below

import java.util.Scanner;
  
  
  public class TempTest{
  	public static void main(String[] args){
  		Scanner sc=new Scanner(System.in);
  		//if(sc.hasNext())
  		String s=sc.nextLine();
  		sc.close();
  		
  		Scanner sc2=new Scanner(System.in);
  		sc2.nextLine();
  		sc2.close();
  	}
  }

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Java are executed sequentially after you perform on your behalf to shut down the flow . close (), you go to call you close the stream has been ; obviously unrealistic
My suggestion is that you do a few methods which contains the input stream , then you can call the main inside the
------ Solution ------------ --------------------------------
System.in main problem is not re- opened, it can end up in the program closed

  		final Scanner scanner=new Scanner(System.in);
  		Runtime.getRuntime().addShutdownHook(new Thread() {
  			@Override
  			public void run() {
  				scanner.close();
  			}
  		});

------ Solution ------------------------------------- -------
you use Eclipse , right ? Eclipse run java program using javaw, not associated with the console , so System.console () is null
If you like
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sc.close () will System.in also turned off, so ...
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public void close () Closes this scanner .
If this scanner has not yet closed, and its underlying readable also implements the Closeable interfaces , close the readable method will be called.
System.in is InputStream object , and turn off after no longer open
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then how to achieve it in a different place to read ? With the Scanner class
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If you have to use System.in, so not all read before the finish do not close the Scanner
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If you have to use System.in, then not all Do not close the Scanner finished before reading  
That first Scanner objects do not close , and then apply the second object.
see youwarning not always feel great. . .
Security Scanner if not there is no other better way to achieve multiple reads input in the console , with the hope of code oh
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can also use this
BufferedReader reader = new BufferedReader (new InputStreamReader (System.in));
The reader can not be closed , but it is not never closed warning
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way too much trouble , not only to create objects of trouble, but also add try ... catch.
Is not there an easier way?
I think there should be a common approach to deal with such issues now !
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I specifically wrote a class

class input
  {
  	final static Scanner sc=new Scanner(System.in);
  }

After all call each
input.sc, and finally the it off. That's all.
Thank you very much , your answer too professional !
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I was a college rookie , would like to ask a question about input
Console cons = System.console (); Why create console object is null

For example, the following code will not execute successfully

Console cons;
  char[] passwd;
  if ((cons = System.console()) != null &&
  (passwd = cons.readPassword("[%s]", "Password:"))!= null) {
       ...
  java.util.Arrays.fill(passwd, ' ');
   }

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lesson
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Although this problem is very low , but if you do not tell , then throw themselves can not think of a moment .
I learn java very short time, a lot of the problem is not clear , thank you advise, thank you very much.