Java IO流

1. 流的分类

  • 按操作数据单位不同分为：字节流(8 bit)，字符流(16 bit)
  • 按数据流的流向不同分为：输入流，输出流
  • 按流的角色的不同分为：节点流，处理流

 

 

 

2. 示例代码

  1 package com.windy.io;
  2 
  3 import java.io.File;
  4 import java.io.FileInputStream;
  5 import java.io.FileOutputStream;
  6 import java.io.FileReader;
  7 import java.io.FileWriter;
  8 import java.io.IOException;
  9 
 10 import org.junit.Test;
 11 
 12 public class IOTest {
 13 
 14     @Test
 15     public void FileStreamTest(){
 16         
 17             File f1 = new File("001.jpg");
 18             File f2 = new File("001-copy.jpg");
 19             
 20             FileInputStream fis = null;
 21             FileOutputStream fos = null;
 22             
 23             try {
 24                     fis = new FileInputStream(f1);
 25                     fos = new FileOutputStream(f2);
 26                     
 27                     byte [] b = new byte[512];
 28                     int len = 0; 
 29                     
 30                     while((len = fis.read(b)) != -1){
 31                             fos.write(b, 0, len);
 32                     }
 33                     
 34                     
 35             } catch (Exception e) {
 36                     e.printStackTrace();
 37             }finally{
 38                 
 39                     if(fis != null){
 40                         try {
 41                             fis.close();
 42                         } catch (IOException e) {
 43                             e.printStackTrace();
 44                         }                        
 45                     }
 46                     if(fos != null){
 47                         try {
 48                             fos.close();
 49                         } catch (IOException e) {
 50                             e.printStackTrace();
 51                         }                        
 52                     }
 53             }
 54         
 55     }
 56     
 57     @Test
 58     public void FileStringTest(){
 59             File f1 = new File("001.txt");
 60             File f2 = new File("001-copy.txt");
 61             
 62             FileReader fis = null;
 63             FileWriter fos = null;
 64             
 65             try {
 66                     fis = new FileReader (f1);
 67                     fos = new FileWriter (f2);
 68                     
 69                     char [] b = new char[10];
 70                     int len = 0; 
 71                     
 72                     while((len = fis.read(b)) != -1){
 73 
 74                             fos.write(b, 0, len);
 75                     }
 76                     
 77                     
 78             } catch (Exception e) {
 79                     e.printStackTrace();
 80             }finally{
 81                 
 82                     if(fis != null){
 83                         try {
 84                             fis.close();
 85                         } catch (IOException e) {
 86                             e.printStackTrace();
 87                         }                        
 88                     }
 89                     if(fos != null){
 90                         try {
 91                             fos.close();
 92                         } catch (IOException e) {
 93                             e.printStackTrace();
 94                         }                        
 95                     }
 96             }
 97         }
 98     
 99     @Test
100     public void BufferTest(){
101         File f1 = new File("001.txt");
102         File f2 = new File("001-copy.txt");
103         
104         FileReader fis = null;
105         FileWriter fos = null;
106         
107         try {
108                 fis = new FileReader (f1);
109                 fos = new FileWriter (f2);
110                 
111                 char [] b = new char[10];        
112                 int len = 0;  
113                 
114                 while((len = fis.read(b)) != -1){
115 
116                         fos.write(b, 0, len);
117                 }
118                 
119                 
120         } catch (Exception e) {
121                 e.printStackTrace();
122         }finally{
123             
124                 if(fis != null){
125                     try {
126                         fis.close();
127                     } catch (IOException e) {
128                         e.printStackTrace();
129                     }                        
130                 }
131                 if(fos != null){
132                     try {
133                         fos.close();
134                     } catch (IOException e) {
135                         e.printStackTrace();
136                     }                        
137                 }
138         }
139         
140         
141     }
142     
143 }
View Code

 

posted @ 2017-03-25 17:31  fengze  阅读(117)  评论(0)  编辑  收藏  举报