Java でファイル操作関数を使用して読み取りおよび書き込み操作を行う方法

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;

public class FileReadExample {
    public static void main(String[] args) {
        try {
            // 打开文件
            File file = new File("test.txt");
            FileInputStream fis = new FileInputStream(file);
            InputStreamReader isr = new InputStreamReader(fis);
            BufferedReader br = new BufferedReader(isr);

            // 逐行读取文件内容
            String line;
            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }

            // 关闭文件
            br.close();
            isr.close();
            fis.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;

public class FileWriteExample {
    public static void main(String[] args) {
        try {
            // 打开文件
            File file = new File("output.txt");
            FileOutputStream fos = new FileOutputStream(file);
            OutputStreamWriter osw = new OutputStreamWriter(fos);
            BufferedWriter bw = new BufferedWriter(osw);

            // 写入数据到文件
            String data = "Hello, World!";
            bw.write(data);

            // 关闭文件
            bw.close();
            osw.close();
            fos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}