IO流，字节流

/**
 * IO流,字节流
 */
import java.io.FileInputStream;
import java.io.FileOutputStream;

public class ByStreamDemo {
    public static void main(String[] args) throws Exception{
//        demo_write();
//        demo_read_1();
        demmo_read_2();
    }
    //写入数据
    public static void demo_write() throws Exception{
        //获取文件
        FileOutputStream fos = new FileOutputStream("F:\\1.txt");
        //写入数据"abcdefg"
        fos.write("abcdefg".getBytes());
        //关闭流
        fos.close();
    }
    //读取数据1
    public static void demo_read_1() throws Exception{
        //获取文件
        FileInputStream fis = new FileInputStream("F:\\1.txt");
        //声明一个数据类型
        int ch = 0;
        //遍历输出
        while((ch = fis.read()) != -1) {
            System.out.print((char) ch);
        }
    }
    //获取数据2
    public static void demmo_read_2() throws Exception{
        //获取文件
        FileInputStream fis = new FileInputStream("F:\\1.txt");
        //声明一个数组
        byte buf[] = new byte[1024];
        //声明一个数据类型
        int len = 0;
        //遍历输出
        while((len = fis.read(buf)) != -1) {
            System.out.println(new String(buf, 0, len));
        }
    }
}