往数据库里面写blob字段数据

思路上是这样的，首先需要将blob字段数据转化为二进制字节流，  
 也就是这样实现的：
 OutStream blobout = blob.getbinaryOutputStream();
 
 然后得到blob字段的数据：通过选定的i值来得到,
 Object obj = newData.get(rsmd.getColumnName(i));
 
 最后把二进制字节流写入这个对象当中，具体的实现是这样的
 blobout.write((File) obj).getBytes());
 
 整个过程这样就结束了。具体的代码是这样的
 if (rs.next()) {
    rsmd = rs.getMetaData();
    BLOB blob = null;
    CLOB clob = null;
    for (int i = 1; i <= rsmd.getColumnCount(); i++) {
     switch (rsmd.getColumnType(i)) {
      case Types.BLOB :
       blob = (BLOB) rs.getBlob(i);
       if (blob != null) {
        blob.trim(0);
        OutputStream blobout =
         blob.getBinaryOutputStream();
        Object obj = newData.get(rsmd.getColumnName(i));
        if (obj instanceof File) {
         blobout.write(((File) obj).getBytes());
        } else if (obj instanceof String) {
         blobout.write(
          (new BASE64Decoder()).decodeBuffer(
           obj.toString()));
        }
        blobout.flush();
        blobout.close();
       }
       break;
      case Types.CLOB :
       clob = (CLOB) rs.getClob(i);
       if (clob != null) {
        //System.out.println("CLOB*****");
        clob.trim(0);
        Writer clobWriter =
         clob.getCharacterOutputStream();
        if (newData
         .get(rsmd.getColumnName(i))
         .toString()
         .equals("")) {
         clobWriter.write(" ");
        } else {
         clobWriter.write(
          newData
           .get(rsmd.getColumnName(i))
           .toString());
        }
        clobWriter.flush();
        clobWriter.close();
       }
       break;
      default :
       break;
     }
    }
    conn.commit();
    return true;
   }