java _io_隨機讀取讀入流RandomAccessFile

• 隨機讀取和寫入流RandomAccessFile
• 支持讀取和寫入隨機訪問文件

• RandomAccessFile raf=new RandomAccessFile(文件對象，讀寫模式);r只讀，rw讀和寫

  private File f;
  //目的地
  private String dir;
  //所有分割后的文件存儲路徑
  private List<String> list;
  //每塊大小
  private int blockSize;
  //塊數
  private int size;

  public n(File f,String dir,int blockSize)
  {
  this.f=f;
  this.dir=dir;
  this.blockSize=blockSize;
  this.list=new ArrayList<String>;
  }

  //初始化
  private void init()
  {
  //總長度
  long len=this.f.length();
  //塊數
  this.size=(int)Math.ceil(len*1.0/blockSize);
  //路徑:
  for(int i=0;i<size;i++)
  {
  this.list.add(this.dir+i+this.f.getName());
  }

  }
  //分割:計算每一塊的起始位置及大小
  public void split()
  {

  }
  public void t3(int i,int first,int real) throws IOException
  {
  RandomAccessFile raf=new RandomAccessFile(this.f,"r");
  RandomAccessFile raf2=new RandomAccessFile(this.list.get(i),"rw");

  raf.seek(first);//從第二個位置開始
  
  byte[] flush=new byte[1024];
  int len=-1;
  while((len=raf.read(flush))!=-1)
  {
      if(real>1024)
      {
          raf2.write(flush,0,len);
          real-=1024;
      }else
      {
  
      raf2.write(flush,0,real);
      break;  //讀取指定大小，讀完退出
  }
  raf2.close();
  raf.close();

  }
  }
  public static void main(String[]args)
  {

  }

  }