public class ClobUtil {  /**   *   * @param insertSQL 插入sql语句 有clob字段时，值必须设置成empty_clob()函数 例:insert into ba valus(1,empty_clob())   * @param updateSQL 带有修改的查询语句,并应增加条件判断.例：select * from BA where ba_id = '"+ba.getBA_id()+"' for update   * @param con 数据库链接   * @param bigString 要插入的clob值   * @param updateColumn 要插入的表字段名   * @return   * @throws SQLException   */  public static Boolean clobInsert(String insertSQL,String updateSQL,Connection con,String bigString,String updateColumn ) throws SQLException{       // 结果集       ResultSet rs = null;       // 插入数据库的sql       String query = insertSQL;       // 设置不自动提交       con.setAutoCommit(false);       // 定义预处理       java.sql.PreparedStatement pstmt = con.prepareStatement( query);       // 执行插入语句       pstmt.executeUpdate();       //清空       pstmt = null;       // 执行更改       query = updateSQL;          //显示执行带有修改方式的select       pstmt = con.prepareStatement(query);       rs = pstmt.executeQuery();       // 采用流的方式处理结果集       if(rs.next())        {         // 得到指定的clob字段         oracle.sql.CLOB singnaturedateClob = (oracle.sql.CLOB)rs.getClob(updateColumn);          // 把clob字段放到输出流当中         BufferedOutputStream out = new BufferedOutputStream(singnaturedateClob.getAsciiOutputStream());         // 判断传入的数据是否为空         if(bigString!=null){         try{          // 把要保存的数据转换成输入流          InputStream  is = (InputStream)(new   ByteArrayInputStream(bigString.getBytes()));        copyStream( is, out );       out.close();     } catch (IOException e) {      // TODO Auto-generated catch block      e.printStackTrace();     }         }       }       rs.close();       con.commit();    return true;  }  /**   * 将输入流写入到输出流当中   * @param is 输入流   * @param os 输出流   * @throws IOException   */  public static void copyStream( InputStream is, OutputStream os )  throws IOException  {   byte[] data             = new byte[4096];   int readed              = is.read(data);   while (readed != -1)   {    os.write(data,0,readed);    readed = is.read(data);   }  }  /**   * 通过Clob对象返回字符串   * @param c   * @return   */  public static String getClobString(Clob c) {          try {             Reader reader=c.getCharacterStream();             if (reader == null) {                 return null;             }             StringBuffer sb = new StringBuffer();             char[] charbuf = new char[4096];             for (int i = reader.read(charbuf); i > 0; i = reader.read(charbuf)) {                 sb.append(charbuf, 0, i);             }             return sb.toString();         } catch (Exception e) {             return "";         }     } }