java文本文件讀取寫入

import java.io.*;

public class FileWriteRead {
    public static void main(String[] args) throws IOException {
        File file = new File("file.txt");

        // 寫入文件
        FileOutputStream fop = new FileOutputStream(file);
        OutputStreamWriter writer = new OutputStreamWriter(fop, "UTF-8");

        writer.append("你好啊2！");
        writer.append("\r\n");
        writer.append("hello teacher");

        writer.close();
        fop.close();

        // 讀取內容
        FileInputStream fip = new FileInputStream(file);
        InputStreamReader reader = new InputStreamReader(fip, "utf-8");
        StringBuilder stringBuilder = new StringBuilder();
        while (reader.ready()) {
            stringBuilder.append((char) reader.read());
        }
        System.out.println(stringBuilder.toString());
        reader.close();
        fip.close();
    }
}

 timit@TIMI:/home/workplace/$ java FileWriteRead 
你好啊2！
hello teacher

主要有
File Class(類)
FileReader Class(類)
FileWriter Class(類)