io fraction rounding block

public class fenkuaiquzheng{
	/**
	 * @param args
	 * @throws IOException
	 */
		//源头
	private  File src;
		//目的地
	private String destDir;
		//分割后每块的存储路径
	private List<String> destpath;
		//每块的大小
	int blockSize	;
		//块数
	int size;
	
	public fenkuaiquzheng(String src, String destDir, int blockSize) {
			super();
			this.src =new File(src);
			this.destDir = destDir;
			this.blockSize = blockSize;
			this.destpath =new ArrayList<>();
			info();
	}
	private void info() {
		//总长度
		long len =this.src.length();
		//每块的大小
		this.size=(int) Math.ceil(((len*1.0)/blockSize));
		//路径
		for(int i=0; i<size; i++) {
			this.destpath.add(destDir+"-->"+i+this.src.getName());
		}
	}
	public  void spil() throws IOException{
		long len =this.src.length();
		int begin =0;		//分段切割读取
		int actualSize = (int) (blockSize>len?len:blockSize);
		for(int i=0; i<size; i++) {
			begin =i*size;
			if(i==size-1) {		//最后一块
				actualSize =(int) len;
			}else {
				actualSize =blockSize;
				len-=actualSize;  //剩余量
			}
			spil2(i,begin,actualSize);
		}
	}
	public void spil2(int i,int begin,int actualSize) throws IOException {
		RandomAccessFile raf =new RandomAccessFile(this.src,"r");
		RandomAccessFile raf2 =new RandomAccessFile(this.destpath.get(i),"rw");
		raf.seek(begin);
		byte [] flush =new byte[1024];
		int len;
		while((len=raf.read(flush))!=-1) {	//获取读取的内容
			if(actualSize>len) {
				raf2.write(flush,0,len);
				actualSize-=len;
			}else {
				raf2.write(actualSize);
				break;
			}
		}
		raf.close();
		raf2.close();
	}
	public void msg(String dest) throws IOException {		//文件的合并
		//输出流
		OutputStream os =new BufferedOutputStream(new FileOutputStream(dest,true));	//读的时候从源头读
		for(int i=0;i<destpath.size(); i++) {
			//输入流
			InputStream is =new BufferedInputStream (new FileInputStream(destpath.get(i)));
			byte[] flush=new byte[1024];
			int len;
			while((len=is.read(flush))!=-1) {
				os.write(flush,0,len);
			}
			os.flush();
			is.close();
		}
		os.close();
	}
		public static void main(String[] args) throws IOException {
			/**
			  try(BufferedReader br = new BufferedReader(new InputStreamReader(new
				URL("http://www.baidu.com").openStream(),"UTF-8"));){ String msg;
			  while((msg=br.readLine())!=null) { System.out.print(msg); }
			  }catch(IOException e) { System.out.println("dd"); }
			 
			PrintStream p =System.out;
			p.print(145);
					//打印流
					p =new PrintStream(new BufferedOutputStream(new FileOutputStream("print.txt")));
					p.print(545);
					p.flush();
					p.close();
					//重定向输出端
					System.setOut(p);
					System.out.println("打印流"); //直接输出到文件中
			*/
		}
}