Java学习之IO流（序列流--SequenceInputStream）

 1     //将1.txt,2.txt,3.txt文件合并到一个文件中
 2     /*
 3      * 方式一、Vector集合是可行的，但效率低
 4      */
 5     /* Vector<FileInputStream> vector=new Vector<FileInputStream>();
 6     vector.add(new FileInputStream("1.txt"));
 7     vector.add(new FileInputStream("2.txt"));
 8     vector.add(new FileInputStream("3.txt"));
 9     Enumeration<FileInputStream> en=vector.elements();
10     SequenceInputStream ss=new SequenceInputStream(en); */
11     
12     /*
13      * 方式二、使用ArrayList集合效率高
14      * 使用集合工具类Collections.enumeration方法将ArrayList集合转成Enumeration<FileInputStream>型对象
15      */
16     
17     ArrayList<FileInputStream> arr=new ArrayList<FileInputStream>();
18     
19     arr.add(new FileInputStream("1.txt"));
20     arr.add(new FileInputStream("2.txt"));
21     arr.add(new FileInputStream("3.txt"));
22     SequenceInputStream ss1=new SequenceInputStream(Collections.enumeration(arr));
23     /*
24      * Collections.enumeration(arr)的实现原理：
25      * 
26      * Enumeration API note：The functionality of this interface is duplicated by the Iterator interface
27      * 翻译：该接口的功能被Iterator接口复制
28      * 
29      * final Iterator<FileInputStream> it=arr.iterator();
30      * SequenceInputStream ss1=new SequenceInputStream(new Enumeration<InputStream>() {
31                 @Override
32                 public boolean hasMoreElements() {
33                 
34                 return it.hasNext();
35                 }
36         
37                 @Override
38                 public InputStream nextElement() {
39                 
40                 return it.next();
41                 }
42         });
43      */
44     byte[] buff=new byte[1024];
45     FileOutputStream out=new FileOutputStream("4.txt");
46     int len=0;
47     while((len=ss1.read(buff))!=-1) {
48         out.write(buff,0,len);
49     }
50     out.close();
51     
52     ss1.close();
53     

 1     public static void splitFile(File file) throws IOException {
 2     // 用读取流关联文件
 3     FileInputStream fis = new FileInputStream(file);
 4 
 5     // 定义一个1M的缓冲区
 6     byte[] buf = new byte[SIZE];
 7 
 8     // 创建目的
 9     FileOutputStream fos = null;
10 
11     int len = 0;
12     int count = 1;
13     File dir = new File("partfiles");
14 
15     if (!dir.exists()) {
16         dir.mkdirs();
17     }
18 
19     while ((len = fis.read(buf)) != -1) {
20         fos = new FileOutputStream(new File(dir, (count++) + ".part"));
21         fos.write(buf,0,len);
22     }
23     fos.close();
24     fis.close();
25     }