Looks like you need: http://commons.apache.org/io/apidocs/org/apache/commons/io/input/CloseShieldInputStream.html Wrap that around System.in before making your reader, and then all will be well, since you won’t do that when you are using a FileInputStream.
Pure Java You can redirect System.in with a single line of code: System.setIn(new FileInputStream(filename)); See System.setIn(). Eclipse config In Eclipse 4.5 or later, the launch configuration dialog can set System.in to read from a file. See the announcement here.
Simply use a custom FilterInputStream instead of System.in: new FilterInputStream(System.in) { @Override public void close() throws IOException { //don’t close System.in! } }
You can use System.in to read from the standard input. It works just like entering it from a keyboard. The OS handles going from file to standard input. import java.util.Scanner; class MyProg { public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.println(“Printing the file passed in:”); while(sc.hasNextLine()) System.out.println(sc.nextLine()); } }
Idiomatic Example: The following is how to properly use the java.util.Scanner class to interactively read user input from System.in correctly( sometimes referred to as stdin, especially in C, C++ and other languages as well as in Unix and Linux). It idiomatically demonstrates the most common things that are requested to be done. package com.stackoverflow.scanner; import … Read more