IO简化概述III

import java.io.*;

public class IOFileWriterNote {
        public static void main(String[] args) throws IOException {
        FileWriter fileWriter = new FileWriter("/Users/christopoher/Desktop/poemFile");
        fileWriter.write("nb");
        fileWriter.append("eyghghgjh efhuehuwf efuheih fehiuhf");
        //fileWriter.flush(); // 刷新
        fileWriter.close(); // 关闭也会导致刷新

        //创建读取功能对象
        FileReader fileReader = new FileReader("/Users/christopoher/Desktop/poemFile");
        //初始化要读取的字符数组与长度 （此时都为空）
        char[] charsNeedToRead = new char[100];
        //文件读取以上长度的字符数组chars 并且赋值所读长度len
        int lenRead = fileReader.read(charsNeedToRead);
        //运用String的数组构造方法将字符数组变为一串String
        String text = new String(charsNeedToRead, 0, lenRead);
        // 长度不是100而是文件中真正的有效长度
        System.out.println(text);
        System.out.println(text.length());
        fileReader.close();

        
        // 字节输入流转为字符输入流
        FileInputStream fileInputStream = new FileInputStream("/Users/christopoher/Desktop/poemFile");
        InputStreamReader isr = new InputStreamReader(fileInputStream);

    }
}