java文件上传到sqlserver数据库的问题：报错

 public static void main(String args[]) { byte a[] = null;// **将测试文件test.doc读入此字节数组 File file1 = new File("D:/test.txt"); File file2 = new File("D:/aa.txt");// 从blob读出的信息写入该文件，和源文件进行对比测试 PDMDataBase db = new PDMDataBase(); try { FileInputStream fin = new FileInputStream(file1); FileOutputStream fout = new FileOutputStream(file2); int flen = (int) file1.length();// 读入文件的字节长度 System.out.println("file length:" + flen); a = new byte[flen]; int i = 0; int itotal = 0; // 将文件读入字节数组 for (; itotal < flen; itotal = i + itotal) { i = fin.read(a, itotal, flen - itotal); } fin.close(); System.out.println("read itotal:" + itotal); String strSQL = null; // 初始化数据库的blob一定要用empty_blob()初始化 strSQL = "insert into UploadFiles(id,[content])" + "values('11',0)"; db.ExecuteSQL(strSQL); // 插入其它数据后，定位BLOB字段 strSQL = "select [content] from UploadFiles where id='11'"; ResultSet rs = db.ExecuteQuerySQL(strSQL); if (rs.next()) { Blob blob = rs.getBlob("content");// 得到blob字段 int j = blob.setBytes(1, a);// 将字节数组写入字段 strSQL = "update UploadFiles set content =(convert(varbinary(800),'" + a + "'))" + " where id='11'"; db.ExecuteSQL(strSQL); System.out.println("j:" + j); } System.out.println("insert into ok"); byte b[] = null;// 保存从blob读出的字节 strSQL = "select [content] from UploadFiles where id='11'"; rs = db.ExecuteQuerySQL(strSQL); if (rs.next()) { Blob blob2 = rs.getBlob("content"); System.out.println("blob2 length:" + blob2.length()); b = blob2.getBytes(1, flen);// 从blob取出字节流数据 System.out.println("b length:" + b.length); } // 将从blob读出的字节写入文件 fout.write(b, 0, b.length); fout.close(); System.out.println("write itotal:" + b.length); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } }