JavaIO使用字节流读写数据

【声明】本文参考自极客学院视频
1、字节流读文件

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

public class ReadByteStream {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try {
			FileInputStream fis=new FileInputStream("text.txt");
			byte input[]=new byte[21];
			fis.read(input);
			
			//String inputString=new String(input);
			String inputString=new String(input, "GBk");
			System.out.println(inputString);
			
			//关闭
			fis.close();
			
			
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

}

2、字节流写文件

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;

public class WriteByteStream {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		try {
			FileOutputStream fos=new FileOutputStream("textw.txt");
			String outString="write 123456写出数据";
			byte output[]=outString.getBytes("GBK");
			fos.write(output);
			
			//关闭
			fos.close();
			
			
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

}

3、通过字节输入输出实现文件拷贝

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

//通过字节输入输出实现文件拷贝
public class CopyByByteStream {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try {
			FileInputStream fis=new FileInputStream("ani.gif");
			FileOutputStream fos=new FileOutputStream("ani_new.gif");
			
			byte input[]=new byte[50];
			
			while (fis.read(input)!=-1) {
				fos.write(input);
			}
			
			fis.close();
			fos.close();
			System.out.println("done");
			
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
	}

}