java字节流

/*
字节流
InputStream
OutputStream 

字节流缓冲区
BufferedInputStream
BufferedOutputStream

System.out:对应的是标准输出设备，控制台
System.in:对应的标准输入设备，键盘

InputStreamReader:字符流转换为字节流，字节流及其缓冲没有readLine方法，先变为字符流缓冲区
*/

package pack;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class Main {

    public static void sys(Object obj) {
        System.out.println(obj);
    }

    public static void main(String[] args) throws IOException {
        //method1();
        //method2();
        //method3();
        //method4();
        method5();
    }

    public static void method1() throws IOException {
        FileOutputStream fos = new FileOutputStream("E:\\1.txt");
        fos.write("abc".getBytes());//write方法里没有字符串参数，转换为字节数组
        //字节流不需要刷新
        fos.close();
    }

    public static void method2() throws IOException {
        FileInputStream fis = new FileInputStream("E:\\1.txt");
        /*int ch = 0;
        while((ch=fis.read())!=-1) //一次读一个
            sys((char)ch);
        fis.close();*/

        byte[] buf = new byte[fis.available()];//fis.available是个数
        int len = 0;
        while((len=fis.read(buf))!=-1)
            sys(new String(buf,0,len));
        fis.close();
    }

    /*拷贝图片，字节流*/
    public static void method3() throws IOException {
        FileOutputStream fos = new FileOutputStream("E:\\2.jpg");
        FileInputStream fis = new FileInputStream("E:\\1.jpg");
        int ch = 0;
        while((ch=fis.read())!=-1)
            fos.write(ch);
        fos.close();
        fis.close();
    }

    /*拷贝mp3,通过缓冲区*/
    public static void method4() throws IOException {
        BufferedOutputStream bufos=new BufferedOutputStream(new FileOutputStream("E:\\2.mp3"));
        BufferedInputStream bufis=new BufferedInputStream(new FileInputStream("E:\\1.mp3"));
        int ch = 0;
        while((ch=bufis.read())!=-1)
            bufos.write(ch);
        bufis.close();
        bufos.close();
    }

    public static void method5() throws IOException {
        //字节流及其缓冲没有readLine方法，先变为字符流缓冲区
        InputStream in = System.in; //获取键盘输入对象
        InputStreamReader isr = new InputStreamReader(in);//字节流转换为字符流
        BufferedReader bufr = new BufferedReader(isr); //字符流缓冲区
        String line = null;
        while((line=bufr.readLine())!=null) {
            if(line.equals("over"))
                break;
            sys(line);
        }

        bufr.close();
    }
}