在java中读取和替换行

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

public class ReadFileLineByLine {
    public static void main(String[] args) {
        String filePath = "path/to/your/file.txt";
        try (BufferedReader br = new BufferedReader(new FileReader(filePath))) {
            String line;
            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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

public class ReplaceFileLineByLine {
    public static void main(String[] args) {
        String filePath = "path/to/your/file.txt";
        String oldString = "old_string";
        String newString = "new_string";
        try (BufferedReader br = new BufferedReader(new FileReader(filePath));
             BufferedWriter bw = new BufferedWriter(new FileWriter(filePath))) {
            String line;
            while ((line = br.readLine()) != null) {
                String newLine = line.replace(oldString, newString);
                bw.write(newLine);
                bw.newLine();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}