###############基本功能
寫

FileWriter fw = new FileWriter("xxx.txt");
fw.write("哈嘍");
fw.close();

讀

FileReader fr = new FileReader("xxx.txt");
int ch = 0;
while((ch = fr.read()) != -1){
    System.out.println((char)ch);
}
fr.close();

###############字符流緩沖區
寫入

private static void writeTextByBuffered() throws
 
 IOException
{
    FileWriter fw = new FileWriter("char_xxx.txt");
    BufferedWriter bw = new BufferedWriter(fw);
    bw.write("小紅");
    bw.newLine();
    bw.write("小花，小華");
    bw.flush();
    bw.close();
}

讀取

private static void writeTextByBuffered() throws IOException
{
    FileWriter fw = new
 
 FileWriter("char_xxx.txt");
    BufferedWriter bw = new BufferedWriter(fw);
    bw.write("小紅");
    bw.newLine();
    bw.write("小花，小華");
    bw.flush();
    bw.close();
}

讀取鍵盤錄入信息，Scanner=流+正則表達式。方法是按照某種規則在讀取數據
BufferedReader bufr = new BufferedReader(new InputStreamReader(System.in);
bufr.readLine();

021.5 IO流——字符流