Read contents of a file using Scanner in Java

This post will discuss how to read the contents of a file using Scanner class in Java.

Scanner is a utility class in java.util package which can parse primitive types and strings using regular expressions. It can read text from any object which implements the Readable interface.

A plausible way of reading a file in Java is to construct a Scanner that produces values scanned from the specified file. This is demonstrated below:

import java.io.File;

import java.io.IOException;

import java.nio.charset.StandardCharsets;

import java.util.Scanner;

class Main

{

public static void main(String[] args)

{

File file = new File("doc.txt");

try (Scanner sc = new Scanner(file, StandardCharsets.UTF_8))

{

while (sc.hasNextLine()) {

System.out.println(sc.nextLine());

}

catch (IOException e) {

e.printStackTrace();

}

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We can also construct a Scanner that produces values scanned from the specified file. This is demonstrated below using the try-with-resources block to automatically takes care of scanner.close().

import java.io.File;

import java.io.IOException;

import java.nio.charset.StandardCharsets;

import java.util.Scanner;

class Main

{

public static void main(String[] args)

{

File file = new File("doc.txt");

String content = null;

try {

try (Scanner scanner = new Scanner(file, StandardCharsets.UTF_8)) {

content = scanner.useDelimiter("\\A").next();

}

} catch (IOException e) {

e.printStackTrace();

}

System.out.println(content);

}

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That’s all about reading the contents of a file using the Scanner class in Java.

Read More:

Read all text from a file into a String in Java

Read contents of a file using Scanner in Java

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