Closing OracleCachedRowSet caused connection closed! Why?

Question

public static void test2() {//using OracleCachedRowSet and STATEMENT
try {
     Object[] arg = {"SERVER.STRT0018",String.valueOf(1071)};
     MessageFormat form = new MessageFormat("select a.TRANEDTM, a.CRDENNO from {0} a where a.POSNO=''{1}''");
     int a = arg.length;
     String sql = form.format(arg);
     Statement st = conn.createStatement();
     ResultSet rs = st.executeQuery(sql);
     // using Oracle implemented Rowset
     OracleCachedRowSet ocrs = new OracleCachedRowSet();
     ocrs.populate(rs);
     rs.close();
     st.close();
     ocrs.last();
     System.out.println("RowCount=" + ocrs.getRow());
     if (ocrs.first()) {
          do {
               System.out.println("TRANEDTM2="
                    + ocrs.getInt(1) + " CRDENNO2="
                    + ocrs.getString(2));
          } while (ocrs.next());
//ocrs.close() //If this is executed, when this function is called for the second time, an exception will be thrown out.
} catch (SQLException e) {
     System.out.println(e.getMessage());
The shared database connection is established outside of the function. If ocrs.close() is executed, there will be an exeception("connection is closed!") thrown out when the funcition is called for the second time. if ocrs.close() is commented, everything will be fine?
Does OracleCachedRowSet needs to be closed explicitly? If I do not close it, is there going to be any potential problem?

Answer 1

public static void test2() {//using OracleCachedRowSet and STATEMENT
try {
     Object[] arg = {"SERVER.STRT0018",String.valueOf(1071)};
     MessageFormat form = new MessageFormat("select a.TRANEDTM, a.CRDENNO from {0} a where a.POSNO=''{1}''");
     int a = arg.length;
     String sql = form.format(arg);
     Statement st = conn.createStatement();
     ResultSet rs = st.executeQuery(sql);
     // using Oracle implemented Rowset
     OracleCachedRowSet ocrs = new OracleCachedRowSet();
     ocrs.populate(rs);
     rs.close();
     st.close();
     ocrs.last();
     System.out.println("RowCount=" + ocrs.getRow());
     if (ocrs.first()) {
          do {
               System.out.println("TRANEDTM2="
                    + ocrs.getInt(1) + " CRDENNO2="
                    + ocrs.getString(2));
          } while (ocrs.next());
//ocrs.close() //If this is executed, when this function is called for the second time, an exception will be thrown out.
} catch (SQLException e) {
     System.out.println(e.getMessage());
The shared database connection is established outside of the function. If ocrs.close() is executed, there will be an exeception("connection is closed!") thrown out when the funcition is called for the second time. if ocrs.close() is commented, everything will be fine?
Does OracleCachedRowSet needs to be closed explicitly? If I do not close it, is there going to be any potential problem?