对Blob对象的处理

 

//保存图片
 public boolean savePhoto(String rid,String idcard){  
  Connection conn=null;
  PreparedStatement pstmt=null;
  FileInputStream file=null;
  Statement stmt=null;
  ResultSet rs=null;
  InputStream in=null;
  FileOutputStream out=null;
  try {
   //基本的jdbc操作
//   Class.forName("oracle.jdbc.driver.OracleDriver");
//   conn=DriverManager.getConnection("jdbc:oracle:thin:@192.168.3.245:1521:orcl", "cdc", "111111");
   
   //从hibernate那获得connection
   Session session = this.getSession();
   conn =session.connection();
   
   conn.setAutoCommit(false);
//   if(rid == null || rid.equals("")){
//    pstmt=conn.prepareStatement("insert into t_a_resident_archives(rid,idcard,photo) values(cdc_seq.NEXTVAL,?,?)");
//    pstmt.setString(1, idcard);
//    file=new FileInputStream("f:\\3.jpg");
//    System.out.println(file.available());
//    pstmt.setBlob(2, file);
//   }else{
    pstmt=conn.prepareStatement("update t_a_resident_archives set photo=? where rid=?");
    pstmt.setString(2, rid);
    file=new FileInputStream("f:\\3.jpg");
    System.out.println(file.available());
    pstmt.setBlob(1, file);
//   }
   pstmt.executeUpdate();
   conn.commit();
   
  //读文件
   stmt=conn.createStatement();
   String sql="select photo from t_a_resident_archives where rid=" + rid;
   rs=stmt.executeQuery(sql);
   byte[] buffer=new byte[1024];
   Blob blob=null;
   while(rs.next()){
    blob=rs.getBlob(1);
   }
   in=blob.getBinaryStream();
   //存放文件的路径
   out=new FileOutputStream("D:\\888.jpg");
   int number=in.read(buffer);
   //把读取的数据放到字节数组，并写到文件中
   while(number!=-1){
    out.write(buffer,0,number);
    number=in.read(buffer);
   }   
   
   rs.close();
   stmt.close();
   file.close();
   in.close();
   out.close();
   conn.close();
   return true;
  } catch (Exception e) {
   e.printStackTrace();
  }
  return false;
  
 }