将1.txt，2.txt，3.txt文件中的数据合并到一个文件中

实例1

1 public static void demo_2() throws IOException { 2         // TODO Auto-generated method stub 3         ArrayList
      
        al=new ArrayList
       
        (); 4         for(int x=0;x<=3;x++){ 5             al.add(new FileInputStream(x+".txt")); 6         } 7         Enumeration
        
          en=Collections.enumeration(al); 8 SequenceInputStream sis=new SequenceInputStream(en); 9 //        BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream("4.txt"));10         FileOutputStream fos=new FileOutputStream("4.txt");11         byte[] buf=new byte[1024];12         int len=0;13         while((len=sis.read(buf))!=-1){14             fos.write(buf, 0, len);15         }16         17         fos.close();18         sis.close();
        
       
      

实例2

ArrayList
      
        al=new ArrayList
       
        ();        for(int x=0;x<=3;x++){            al.add(new FileInputStream(x+".txt"));        }        final Iterator
        
          it=al.iterator();        Enumeration
         
           en=new Enumeration
          
           (){            @Override            public boolean hasMoreElements() {                // TODO Auto-generated method stub                return it.hasNext();            }            @Override            public FileInputStream nextElement() {                // TODO Auto-generated method stub                return it.next();            }            };
          
         
        
       
      

 

实例3

1 Vector
      
        v=new Vector
       
        (); 2         v.add(new FileInputStream("1.txt")); 3         v.add(new FileInputStream("2.txt")); 4         v.add(new FileInputStream("3.txt")); 5         Enumeration
        
          en=v.elements(); 6         SequenceInputStream sis=new SequenceInputStream(en); 7 //        BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream("4.txt")); 8         FileOutputStream fos=new FileOutputStream("4.txt"); 9         byte[] buf=new byte[1024];10         int len=0;11         while((len=sis.read(buf))!=-1){12             fos.write(buf, 0, len);13         }14         15         fos.close();16         sis.close();