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Questions tagged [java.util.scanner]

A simple text scanner in the JDK which can parse primitive types and strings using regular expressions.

Use this tag for questions related to the Java API library class java.util.Scanner, a class added to the API in Java 5. The class is, according to the Javadoc:

a simple text scanner which can parse primitive types and strings using regular expressions.

Its source can range from a file, the console, or even a string. (This class replaces the older class java.util.StringTokenizer, which was used prior to Java 5 for the same purpose but has less functionality compared to Scanner).

Important canonical posts with this tag are:

Related tags:

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How to read a text file directly from Internet using Java?

I am trying to read some words from an online text file. I tried doing something like this File file = new File("http://www.puzzlers.org/pub/wordlists/pocket.txt"); Scanner scan = new Scanner(file); but it didn't work, I am getting…
randomizertech
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java.util.NoSuchElementException: No line found

I got an run time exception in my program while I am reading a file through a Scanner. java.util.NoSuchElementException: No line found at java.util.Scanner.nextLine(Unknown Source) at Day1.ReadFile.read(ReadFile.java:49) at…
Ashish Panery
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Close a Scanner linked to System.in

I have a Scanner linked to System.in. Now, after using the Scanner, I should close it, as it is bad coding practice to leave it open. But, if I close the Scanner, I will also be closing System.in! Can anyone tell me how I can close the Scanner…
JavaNewbie_M107
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How to handle infinite loop caused by invalid input (InputMismatchException) using Scanner

So, I'm getting stuck with this piece of code: import java.util.InputMismatchException; import java.util.Scanner; public class ConsoleReader { Scanner reader; public ConsoleReader() { reader = new Scanner(System.in); …
mateusmaso
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Scanner doesn't see after space

I am writing a program that asks for the person's full name and then takes that input and reverses it (i.e John Doe - Doe, John). I started by trying to just get the input, but it is only getting the first name. Here is my code: public static void…
igeer12
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How to read multiple Integer values from a single line of input in Java?

I am working on a program and I want to allow a user to enter multiple integers when prompted. I have tried to use a scanner but I found that it only stores the first integer entered by the user. For example: Enter multiple integers: 1 3 5 The…
Steven
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Is there an equivalent to the Scanner class in C# for strings?

In Java I can pass a Scanner a string and then I can do handy things like, scanner.hasNext() or scanner.nextInt(), scanner.nextDouble() etc. This allows some pretty clean code for parsing a string that contains rows of numbers. How is this done in…
mmcdole
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Is it safe not to close a Java Scanner, provided I close the underlying readable?

If I have a method that takes a reader and I want to operate on the reader with a Scanner like so: Scanner scanner = new Scanner(reader); while(scanner.hasNext()) { //blah blah blah } Is it safe not to close scanner? Documentation says that it…
Anthony
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Read line with Scanner

EDIT for further readers: the problem was that my input file was corrupted. I don't understand what I'm doing wrong : I was using this code : File f = new File("C:\\Temp\\dico.txt"); BufferedReader r = null; try { r = new…
Sharcoux
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Java String Scanner input does not wait for info, moves directly to next statement. How to wait for info?

I am writing a simple program that prompts a user to enter a number of students, then asks the user to enter each student's name and score in order to determine which student has the highest score. I have written the program code and it compiles. …
user1011064
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How to use java.util.Scanner to correctly read user input from System.in and act on it?

This is meant to be a canonical question/answer that can be used as a duplicate target. These requirements are based on the most common questions posted every day and may be added to as needed. They all require the same basic code structure…
user177800
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5 answers

Read next word in java

I have a text file that has following content: ac und accipio annehmen ad zu adeo hinzugehen ... I read the text file and iterate through the lines: Scanner sc = new Scanner(new File("translate.txt")); while(sc.hasNext()){ String line =…
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Scanner doesn't read whole sentence - difference between next() and nextLine() of scanner class

I'm writing a program which allows the user to input his data then outputs it. Its 3/4 correct but when it arrives at outputting the address it only prints a word lets say only 'Archbishop' from 'Archbishop Street'. How do I fix this? import…
Bonett09
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How to use Scanner to accept only valid int as input

I'm trying to make a small program more robust and I need some help with that. Scanner kb = new Scanner(System.in); int num1; int num2 = 0; System.out.print("Enter number 1: "); num1 = kb.nextInt(); while(num2 < num1) { System.out.print("Enter…
John
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Scanner is never closed

I'm working on a game and I came across a little problem with my scanner. I'm getting a resource leak scanner never closed. But I thought my scanner was working before without closing it. But now it ain't. Anyone can help me out here? import…
Niek van der Linden
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