BufferedReader，缓冲输入字符流

Posted 2020-08-20 hgfs瑞

1、

/**
 * 输入字符流：
 * --------|Reader 所有输入字符流的基类。抽象类
 * -----------|FileReader 读取文件字符串的输入字符流。
 * -----------|BufferedReader 缓冲输入字符流。目的是：提高读取效率和拓展FileReader的功能。（该类内部也是维护了字节数组）
 */
public class Demo1 {
    public static void main(String[] args) throws IOException {
        File file = new File("E:\\a.txt");
        //建立通道
        FileReader fileReader =new FileReader(file);
        //建立缓冲输入字符流
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        //读取数据
        int content = 0;
        while ((content = bufferedReader.read())!=-1) {
            System.out.print((char)content);
        }
        bufferedReader.close();
    }
}

2、一次读一行

public class Demo2 {
    public static void main(String[] args) throws IOException {
        File file = new File("E:\\a.txt");
        //建立通道
        FileReader fileReader =new FileReader(file);
        //建立缓冲输入字符流
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        //读取数据
        String content=null;
        //一次读一行，注意返回的数据
        while ((content = bufferedReader.readLine())!=null) {
            System.out.println(content);
        }
        bufferedReader.close();
    }
}

3、bufferedWriter

public class Demo2 {
    public static void main(String[] args) throws IOException {
        File file = new File("E:\\b.txt");
        FileWriter fileWriter = new FileWriter(file,true);
        BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
        //String string="努力编程";
        String string="哈哈";
        bufferedWriter.newLine();//相当于换行！！
        bufferedWriter.write(string);
        bufferedWriter.close();
    }
}