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  • Java学习之IO字节流

     字节流分为FileInputStream 和FileOutputStream

     1 package com.io;
     2 
     3 import java.io.File;
     4 import java.io.FileInputStream;
     5 import java.io.FileNotFoundException;
     6 import java.io.IOException;
     7 import java.io.InputStream;
     8 /**
     9  * 文件字节流的读取
    10  * @author ganhang
    11  *
    12  */
    13 public class FileInputStreamDemo {
    14     public static void main(String[] args) {
    15         File file=new File("1.txt");
    16         try {
    17             InputStream is=new FileInputStream(file);
    18             byte [] b= new byte[10];
    19             int len=-1;
    20             StringBuilder sb=new StringBuilder();//存读取的数据
    21             while((len=is.read(b))!=-1){
    22                 sb.append(new String(b,0,len));
    23             }
    24             is.close();
    25             System.out.println(sb);
    26         } catch (FileNotFoundException e) {
    27             e.printStackTrace();
    28         } catch (IOException e) {
    29             e.printStackTrace();
    30         }
    31         
    32     }
    33 }
     1 package com.io;
     2 
     3 import java.io.File;
     4 import java.io.FileNotFoundException;
     5 import java.io.FileOutputStream;
     6 import java.io.IOException;
     7 import java.io.OutputStream;
     8 /**
     9  * 文件字节流的写入
    10  * @author ganhang
    11  *
    12  */
    13 public class FileOutputStreamDemo {
    14     public static void main(String[] args) {
    15         File file = new File("1.txt");
    16         if (!file.exists()) {
    17             try {
    18                 file.createNewFile();//没有则创建文件
    19             } catch (IOException e) {
    20                 e.printStackTrace();
    21             }
    22         } else {
    23             try {
    24                 OutputStream fos = new FileOutputStream(file, true);//文件末尾添加,不是覆盖
    25                 byte[] info = "hello,world".getBytes();
    26                 fos.write(info);
    27                 fos.close();
    28                 System.out.println("写入成功!");
    29             } catch (FileNotFoundException e) {
    30                 e.printStackTrace();
    31             } catch (IOException e) {
    32                 e.printStackTrace();
    33             }
    34         }
    35     }
    36 }
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  • 原文地址:https://www.cnblogs.com/ganhang-acm/p/5154293.html
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