使用java在文本文件中查找字符串的问题

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

public class FileSearch {
    public static void main(String[] args) {
        String filePath = "path/to/file.txt";
        String targetString = "search string";

        try (BufferedReader br = new BufferedReader(new FileReader(filePath))) {
            String line;
            while ((line = br.readLine()) != null) {
                if (line.contains(targetString)) {
                    System.out.println("Found in line: " + line);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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

public class FileSearch {
    public static void main(String[] args) {
        String filePath = "path/to/file.txt";
        String targetString = "search string";

        try {
            Scanner scanner = new Scanner(new File(filePath));
            int lineNumber = 1;
            while (scanner.hasNextLine()) {
                String line = scanner.nextLine();
                if (line.contains(targetString)) {
                    System.out.println("Found in line " + lineNumber + ": " + line);
                }
                lineNumber++;
            }
            scanner.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
}

import org.apache.commons.io.FileUtils;
import org.apache.commons.lang3.StringUtils;

import java.io.File;
import java.io.IOException;
import java.util.List;

public class FileSearch {
    public static void main(String[] args) {
        String filePath = "path/to/file.txt";
        String targetString = "search string";

        try {
            List<String> lines = FileUtils.readLines(new File(filePath), "UTF-8");
            for (int i = 0; i < lines.size(); i++) {
                String line = lines.get(i);
                if (StringUtils.containsIgnoreCase(line, targetString)) {
                    System.out.println("Found in line " + (i + 1) + ": " + line);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}