JavaIO使用字節流讀寫數據

【聲明】本文參考自極客學院視頻
1、字節流讀文件

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);
			
			//關閉
			fis.close();
			
			
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

}

2、字節流寫文件

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寫出數據";
			byte output[]=outString.getBytes("GBK");
			fos.write(output);
			
			//關閉
			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、通過字節輸入輸出實現文件拷貝

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

//通過字節輸入輸出實現文件拷貝
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();
		}
		
		
	}

}