private void  proxyConnection() throws Exception {
  Properties properties = new Properties();
  properties.put("PROXY_USER_NAME", "pu_user_1");
  OracleConnection conn = (OracleConnection)DriverManager.getConnection(
  "jdbc:oracle:thin:pu_pool_user/pu_pool_user@localhost:1521:ora1012",
  properties);
  conn.openProxySession(OracleConnection.PROXYTYPE_USER_NAME, properties); 
  printUserInfo(conn);
  conn.close();
}