需求： 把一首MP3切成n份，每份是1m，然后再合并起来。

public class Demo2 {
    
    public static void main(String[] args) throws IOException {
//      cutFile();
        mergeFile();
    }
    
    
    //合并mp3文件
    public static void mergeFile() throws IOException{
        File dir= new File("f:\\music");
        File[] files = dir.listFiles(); //获取到文件夹中的所有子文件
        //创建一个Vector对象存储FileInputStream对象
        Vector<FileInputStream> vector = new Vector<FileInputStream>();
        //遍历数组，
        for(int i = 0; i<files.length ; i++){
            if(files[i].getName().endsWith(".mp3")){
                vector.add(new FileInputStream(files[i]));
            }
        }
        
        //创建一个序列流对象
        SequenceInputStream inputStream = new SequenceInputStream(vector.elements());
        //创建一个输出流对象
        FileOutputStream fileOutputStream = new  FileOutputStream("f:\\晚风.mp3");
        //边读边写
        byte[] buf = new byte[1024];
        int length = 0; 
        while((length = inputStream.read(buf))!=-1){
            fileOutputStream.write(buf,0,length);
        }
        
        //关闭资源
        fileOutputStream.close();
        inputStream.close();                    
    }
    
    //切割mp3
    public static void cutFile() throws IOException{
        File file = new File("F:\\美女\\1.mp3");
        FileInputStream fileInputStream = new FileInputStream(file);
        byte[] buf = new byte[1024*1024];
        int length = 0 ; 
        int count = 1; 
        
        while((length = fileInputStream.read(buf))!=-1){            
            
            //每读取一次，则生成一个文件
            FileOutputStream fileOutputStream = new FileOutputStream("F:\\music\\part"+count+".mp3");
            //把读取到的数据写出
            fileOutputStream.write(buf,0,length);
            count++;
            //关闭资源
            fileOutputStream.close();
        }
        //关闭资源
        fileInputStream.close();    
    }
}