SequenceInputStream

//合并多个流
    public static void merge3() throws IOException{
        File file1=new File("E:\a.txt");
        File file2=new File("E:\b.txt");
        File file3=new File("E:\c.txt");
        FileOutputStream fileOutputStream=new FileOutputStream("E:\d.txt");
        FileInputStream file1InputStream=new FileInputStream(file1);
        FileInputStream file2InputStream=new FileInputStream(file2);
        FileInputStream file3InputStream=new FileInputStream(file3);
        Vector<FileInputStream> vector=new Vector<FileInputStream>();
        vector.add(file1InputStream);
        vector.add(file2InputStream);
        vector.add(file3InputStream);
        Enumeration<FileInputStream> e=vector.elements();
        SequenceInputStream sequenceInputStream=new SequenceInputStream(e);
        byte[] buf= new byte[1024];
        int length=0;
        while((length=sequenceInputStream.read(buf))!=-1){
            fileOutputStream.write(buf,0,length);
        }
        sequenceInputStream.close();
        fileOutputStream.close();
        
    }
    
    //借助SequenceInputStream合并
    public static void merge2() throws IOException{
        File file1=new File("E:\a.txt");
        File file2=new File("E:\b.txt");
        File outFile=new File("E:\c.txt");
        FileInputStream file1InputStream=new FileInputStream(file1);
        FileInputStream file2InputStream=new FileInputStream(file2);
        FileOutputStream fileOutputStream=new FileOutputStream(outFile);
        SequenceInputStream sequenceInputStream=new SequenceInputStream(file1InputStream, file2InputStream);
        byte[] buf= new byte[1024];
        int length=0;
        while((length=sequenceInputStream.read(buf))!=-1){
            fileOutputStream.write(buf,0,length);
        }
        sequenceInputStream.close();
        fileOutputStream.close();
    
    }
    
    
    //借助数组进行合并
    public static void merge1() throws IOException{
        File file1=new File("E:\a.txt");
        File file2=new File("E:\b.txt");
        File outFile=new File("E:\c.txt");
        FileInputStream file1InputStream=new FileInputStream(file1);
        FileInputStream file2InputStream=new FileInputStream(file2);
        FileOutputStream fileOutputStream=new FileOutputStream(outFile);
        
        ArrayList<FileInputStream> list=new ArrayList<FileInputStream>();
        list.add(file1InputStream);
        list.add(file2InputStream);
        byte[] buf=new byte[1024];
        int length=0;
        for(int i=0;i<list.size();i++){
            FileInputStream fileInputStream=list.get(i);
            while((length=fileInputStream.read(buf))!=-1){
                fileOutputStream.write(buf,0,length);
            }
            fileInputStream.close();
        }
        fileOutputStream.close();
    }