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comparison src/main/java/nl/cwi/monetdb/jdbc/MonetConnection.java @ 300:8cc3b51d1984

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Add a utility method to close objects ignoring any possible SQLExceptions thrown. Use it in finally clauses to reduce object code.
author Martin van Dinther <martin.van.dinther@monetdbsolutions.com>
date Thu, 15 Aug 2019 16:57:25 +0200 (2019-08-15)
parents c5efd6e661e5
children 0b01771d5f8a
comparison
equal deleted inserted replaced
299:1f0324072b0c 300:8cc3b51d1984
1330 // SQLState = 25005 1330 // SQLState = 25005
1331 isValid = true; 1331 isValid = true;
1332 } 1332 }
1333 /* ignore stmt errors/exceptions, we are only testing if the connection is still alive and usable */ 1333 /* ignore stmt errors/exceptions, we are only testing if the connection is still alive and usable */
1334 } finally { 1334 } finally {
1335 if (rs != null) { 1335 closeResultsetStatement(rs, stmt);
1336 try {
1337 rs.close();
1338 } catch (Exception e2) { /* ignore error */ }
1339 }
1340 if (stmt != null) {
1341 try {
1342 stmt.close();
1343 } catch (Exception e2) { /* ignore error */ }
1344 }
1345 } 1336 }
1346 return isValid; 1337 return isValid;
1347 } 1338 }
1348 1339
1349 /** 1340 /**
1509 st = createStatement(); 1500 st = createStatement();
1510 if (st != null) 1501 if (st != null)
1511 st.execute("SET SCHEMA \"" + schema + "\""); 1502 st.execute("SET SCHEMA \"" + schema + "\"");
1512 // do not catch any Exception, just let it propagate 1503 // do not catch any Exception, just let it propagate
1513 } finally { 1504 } finally {
1514 if (st != null) { 1505 closeResultsetStatement(null, st);
1515 try {
1516 st.close();
1517 } catch (SQLException e) { /* ignore */ }
1518 }
1519 } 1506 }
1520 } 1507 }
1521 1508
1522 /** 1509 /**
1523 * Retrieves this Connection object's current schema name. 1510 * Retrieves this Connection object's current schema name.
1544 cur_schema = rs.getString(1); 1531 cur_schema = rs.getString(1);
1545 } 1532 }
1546 } 1533 }
1547 // do not catch any Exception, just let it propagate 1534 // do not catch any Exception, just let it propagate
1548 } finally { 1535 } finally {
1549 if (rs != null) { 1536 closeResultsetStatement(rs, st);
1550 try {
1551 rs.close();
1552 } catch (SQLException e) { /* ignore */ }
1553 }
1554 if (st != null) {
1555 try {
1556 st.close();
1557 } catch (SQLException e) { /* ignore */ }
1558 }
1559 } 1537 }
1560 if (cur_schema == null) 1538 if (cur_schema == null)
1561 throw new SQLException("Failed to fetch schema name", "02000"); 1539 throw new SQLException("Failed to fetch schema name", "02000");
1562 return cur_schema; 1540 return cur_schema;
1563 } 1541 }
1726 } 1704 }
1727 } 1705 }
1728 } catch (SQLException se) { 1706 } catch (SQLException se) {
1729 /* ignore */ 1707 /* ignore */
1730 } finally { 1708 } finally {
1731 if (rs != null) { 1709 closeResultsetStatement(rs, stmt);
1732 try {
1733 rs.close();
1734 } catch (SQLException e) { /* ignore */ }
1735 }
1736 if (stmt != null) {
1737 try {
1738 stmt.close();
1739 } catch (SQLException e) { /* ignore */ }
1740 }
1741 } 1710 }
1742 // for debug: System.out.println("testTableExists(" + tablename + ") returns: " + exists); 1711 // for debug: System.out.println("testTableExists(" + tablename + ") returns: " + exists);
1743 return exists; 1712 return exists;
1713 }
1714
1715 /**
1716 * Closes a ResultSet and/or Statement object without throwing any SQLExceptions
1717 * It can be used in the finally clause after creating a Statement and
1718 * (optionally) executed a query which produced a ResultSet.
1719 *
1720 * @param rs ResultSet object to be closed. It may be null
1721 * @param st Statement object to be closed. It may be null
1722 */
1723 static final void closeResultsetStatement(final ResultSet rs, final Statement st) {
1724 if (rs != null) {
1725 try {
1726 rs.close();
1727 } catch (SQLException e) { /* ignore */ }
1728 }
1729 if (st != null) {
1730 try {
1731 st.close();
1732 } catch (SQLException e) { /* ignore */ }
1733 }
1744 } 1734 }
1745 1735
1746 /** 1736 /**
1747 * Sends the given string to MonetDB as special transaction command. 1737 * Sends the given string to MonetDB as special transaction command.
1748 * All possible returned information is discarded. 1738 * All possible returned information is discarded.