java - oracle.sql.CLOB 无法转换为 oracle.sql.DatumWithConnection

Question

这是我的java代码。我使用的是 Wildfly 10.0.0 和 java 1.8 以及 oracle 12c。

   public void getCellValue(){         
            PreparedStatement pstat = getConnection().prepareStatement("select empty_clob() from dual");
            resultSet = pstat.executeQuery();
            resultSet.next();
            DatumWithConnection datum = (DatumWithConnection) resultSet.getClob(1);
            OracleConnection oconn = datum.getOracleConnection();
   }

 public Connection getConnection()
 {
    InitialContext ic = new InitialContext();
    this.mDataSource = ((DataSource)ic.lookup(lookupName));
    this.mConnection = this.mDataSource.getConnection();
    return this.mConnection;
 }

当我调用函数 getCellValue 时，出现这样的错误。

22:18:56,622 ERROR [stderr] (default task-13) java.lang.ClassCastException: oracle.sql.CLOB cannot be cast to

oracle.sql.DatumWithConnection

如何修复此错误？感谢您的观看。

Answer 1

以下代码有效

public class MyTest
{
        public static void main(String[] args) throws SQLException {
                MyTest test1 = new MyTest();
                oracle.jdbc.internal.OracleConnection conn = test1.getConnection();
                test1. getCellvalue(conn);
        }

        private void getCellvalue(Connection dbConnection) throws SQLException {        
                PreparedStatement pstat = dbConnection.prepareStatement("select empty_clob() from dual");
                ResultSet resultSet = pstat.executeQuery();
                resultSet.next();
                DatumWithConnection datum = (DatumWithConnection) resultSet.getClob(1);
                OracleConnection oconn = datum.getOracleConnection()
        }

        private oracle.jdbc.internal.OracleConnection getConnection() throws SQLException {
                    String url = "jdbc:oracle:thin:@host:port/service_name”;
                    OracleDataSource ds = new OracleDataSource();
                    Properties prop = new Properties();
                    prop.setProperty("user","scott");
                    prop.setProperty("password","tiger");
                    ds.setConnectionProperties(prop);
                    ds.setURL(url);
                    oracle.jdbc.internal.OracleConnection conn =
                    (oracle.jdbc.internal.OracleConnection)ds.getConnection();
                    return conn;

        }
}

也许使用 resultSet.getCLOB 而不是 resultSet.getClob。