IO流_文件切割与合并

 1 import java.io.File;
 2 import java.io.FileInputStream;
 3 import java.io.FileOutputStream;
 4 import java.io.IOException;
 5 
 6 public class SplitFileDemo {
 7     private static final int SIZE = 1024*1024;//1M=1024*1024个字节
 8 
 9     public static void main(String[] args) throws IOException {
10         File file = new File("F:\\jian.avi");
11         splitFileDemo(file);
12         
13     }
14     public static void splitFileDemo(File file) throws IOException {
15         
16         //用读取流关联一个文件
17         FileInputStream fis = new FileInputStream(file);
18         //定义一个1M的缓冲区
19         byte[] buf = new byte[SIZE];
20         
21         //创建目的
22         FileOutputStream fos = null;
23         
24         File dir = new File("F:\\partfiles");
25         
26         if(!dir.exists()){
27             dir.mkdirs();
28         }
29         
30         int count = 1;
31         int len = 0;
32         while((len = fis.read(buf))!=-1){
33             fos = new FileOutputStream(new File(dir,(count++)+".part"));//扩展名可以依据软件的需求来定义，但不要是txt这些扩展名，因为切割完的文件不能直接读取
34             fos.write(buf,0,len);
35         }
36         fos.close();
37         fis.close();
38     }
39 }

 1 import java.io.File;
 2 import java.io.FileInputStream;
 3 import java.io.FileOutputStream;
 4 import java.io.IOException;
 5 import java.io.SequenceInputStream;
 6 import java.util.ArrayList;
 7 import java.util.Collections;
 8 import java.util.Enumeration;
 9 import java.util.Properties;
10 
11 public class MergeFile {
12     public static void main(String[] args) throws IOException {
13 
14         File dir = new File("c:\\partfiles");
15         
16         mergeFile(dir);
17     }
18     public static void mergeFile(File dir) throws IOException{
19         
20         
21         ArrayList<FileInputStream> al = new ArrayList<FileInputStream>();
22         
23         for(int x=1; x<=3 ;x++){
24             al.add(new FileInputStream(new File(dir,x+".part")));
25         }
26         
27         Enumeration<FileInputStream> en = Collections.enumeration(al);
28         SequenceInputStream sis = new SequenceInputStream(en);
29         
30         FileOutputStream fos = new FileOutputStream(new File(dir,"1.bmp"));
31         
32         byte[] buf = new byte[1024];
33         
34         int len = 0;
35         while((len=sis.read(buf))!=-1){
36             fos.write(buf,0,len);
37         }
38         
39         fos.close();
40         sis.close();
41         
42     }
43 
44 }