How to read text data in java

Use the following methods in Java to read text data: Scanner class: Create a Scanner object, use the nextLine() method to read data line by line, and close the Scanner. BufferedReader class: Create a BufferedReader object, use the readLine() method to read data line by line, and close the BufferedReader.

How to read text data using Java

Introduction
In Java Reading in text data is a basic task used in processing various text files. This article will introduce the common methods of reading text data in Java using the following methods:

Method 1: Using the Scanner class

The Scanner class is a method used to read in text data from various Utility classes for reading data (including text files) from input sources. The following are the steps to use Scanner to read text data:

1. Create Scanner object: Use new Scanner(File file) to create a Scanner object, wherefile is the text file to be read.
2. Read data: Use the nextLine() method to read data line by line until the end of the file is reached.
3. Close Scanner: After processing the file, use the close() method to close the Scanner.

Example

import java.io.File;
import java.util.Scanner;

public class ReadTextFile {

    public static void main(String[] args) {
        try {
            // 创建 Scanner 对象
            Scanner scanner = new Scanner(new File("text.txt"));

            // 按行读取数据
            while (scanner.hasNextLine()) {
                String line = scanner.nextLine();
                System.out.println(line);
            }

            // 关闭 Scanner
            scanner.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Method 2: Using the BufferedReader class

The BufferedReader class provides an efficient method to read text data line by line. The following are the steps to use BufferedReader to read text data:

1. Create a BufferedReader object: Use new BufferedReader(FileReader reader) to create a BufferedReader object, wherereader is a FileReader object pointing to a text file.
2. Read data: Use the readLine() method to read data line by line until the end of the file is reached.
3. Close BufferedReader: After processing the file, use the close() method to close the BufferedReader.

Example

import java.io.BufferedReader;
import java.io.FileReader;

public class ReadTextFile {

    public static void main(String[] args) {
        try {
            // 创建 BufferedReader 对象
            BufferedReader reader = new BufferedReader(new FileReader("text.txt"));

            // 按行读取数据
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }

            // 关闭 BufferedReader
            reader.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

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