java 向 oracle 的字段 Blob 读图片问题

sql = "select tp from gys_sp where id_admin=? and spbm=? FOR UPDATE";

ps = conn.prepareStatement(sql);
ps.setInt(1, _sp.getId());
ps.setString(2, _sp.get_spbm());
rs = ps.executeQuery();
if (rs.next()) {
BLOB blob = (BLOB) rs.getBlob("tp");
OutputStream outStream = ((BLOB) blob)
.getBinaryOutputStream();
System.out.println(_sp.get_file1());
File file = new File(_sp.get_file1());
BufferedInputStream inStream = new BufferedInputStream(
new FileInputStream(file));
byte[] b = new byte[blob.getBufferSize()];

int lenth = 0;

while ((lenth = inStream.read(b)) != -1) {
outStream.write(b, 1, lenth);
}

inStream.close();
outStream.flush();
outStream.close();
conn.commit();
写是写到里面了.数据也有.不过读的时候.
ps = conn.prepareStatement(sql) ;
ps.setInt(1,id) ;
rs = ps.executeQuery() ;
if (rs.next()) {
blob = ((oracle.jdbc.OracleResultSet)rs).getBLOB("tp"); 
name = rs.getString("tp_name") ;
InputStream in = blob.getBinaryStream();
// try {
//                     long nLen = blob.length();
//     &