| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.tomcat.dbcp.dbcp2; |
| |
| import java.lang.management.ManagementFactory; |
| import java.sql.Connection; |
| import java.sql.PreparedStatement; |
| import java.sql.ResultSet; |
| import java.sql.SQLException; |
| import java.util.Collection; |
| |
| import javax.management.InstanceAlreadyExistsException; |
| import javax.management.InstanceNotFoundException; |
| import javax.management.MBeanRegistrationException; |
| import javax.management.MBeanServer; |
| import javax.management.NotCompliantMBeanException; |
| import javax.management.ObjectName; |
| |
| import org.apache.tomcat.dbcp.pool2.ObjectPool; |
| |
| /** |
| * A delegating connection that, rather than closing the underlying |
| * connection, returns itself to an {@link ObjectPool} when |
| * closed. |
| * |
| * @author Rodney Waldhoff |
| * @author Glenn L. Nielsen |
| * @author James House |
| * @since 2.0 |
| */ |
| public class PoolableConnection extends DelegatingConnection<Connection> |
| implements PoolableConnectionMXBean { |
| |
| private static MBeanServer MBEAN_SERVER = null; |
| |
| static { |
| try { |
| MBEAN_SERVER = ManagementFactory.getPlatformMBeanServer(); |
| } catch (Exception ex) { |
| // ignore - JMX not available |
| } |
| } |
| |
| /** The pool to which I should return. */ |
| private final ObjectPool<PoolableConnection> _pool; |
| |
| private final ObjectName _jmxName; |
| |
| // Use a prepared statement for validation, retaining the last used SQL to |
| // check if the validation query has changed. |
| private PreparedStatement validationPreparedStatement = null; |
| private String lastValidationSql = null; |
| |
| /** |
| * Indicate that unrecoverable SQLException was thrown when using this connection. |
| * Such a connection should be considered broken and not pass validation in the future. |
| */ |
| private boolean _fatalSqlExceptionThrown = false; |
| |
| /** |
| * SQL_STATE codes considered to signal fatal conditions. Overrides the |
| * defaults in {@link Utils#DISCONNECTION_SQL_CODES} (plus anything starting |
| * with {@link Utils#DISCONNECTION_SQL_CODE_PREFIX}). |
| */ |
| private final Collection<String> _disconnectionSqlCodes; |
| |
| /** Whether or not to fast fail validation after fatal connection errors */ |
| private final boolean _fastFailValidation; |
| |
| /** |
| * |
| * @param conn my underlying connection |
| * @param pool the pool to which I should return when closed |
| * @param jmxName JMX name |
| * @param disconnectSqlCodes SQL_STATE codes considered fatal disconnection errors |
| * @param fastFailValidation true means fatal disconnection errors cause subsequent |
| * validations to fail immediately (no attempt to run query or isValid) |
| */ |
| public PoolableConnection(final Connection conn, |
| final ObjectPool<PoolableConnection> pool, final ObjectName jmxName, final Collection<String> disconnectSqlCodes, |
| final boolean fastFailValidation) { |
| super(conn); |
| _pool = pool; |
| _jmxName = jmxName; |
| _disconnectionSqlCodes = disconnectSqlCodes; |
| _fastFailValidation = fastFailValidation; |
| |
| if (jmxName != null) { |
| try { |
| MBEAN_SERVER.registerMBean(this, jmxName); |
| } catch (InstanceAlreadyExistsException | |
| MBeanRegistrationException | NotCompliantMBeanException e) { |
| // For now, simply skip registration |
| } |
| } |
| } |
| |
| /** |
| * |
| * @param conn my underlying connection |
| * @param pool the pool to which I should return when closed |
| * @param jmxName JMX name |
| */ |
| public PoolableConnection(final Connection conn, |
| final ObjectPool<PoolableConnection> pool, final ObjectName jmxName) { |
| this(conn, pool, jmxName, null, false); |
| } |
| |
| |
| @Override |
| protected void passivate() throws SQLException { |
| super.passivate(); |
| setClosedInternal(true); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| * <p> |
| * This method should not be used by a client to determine whether or not a |
| * connection should be return to the connection pool (by calling |
| * {@link #close()}). Clients should always attempt to return a connection |
| * to the pool once it is no longer required. |
| */ |
| @Override |
| public boolean isClosed() throws SQLException { |
| if (isClosedInternal()) { |
| return true; |
| } |
| |
| if (getDelegateInternal().isClosed()) { |
| // Something has gone wrong. The underlying connection has been |
| // closed without the connection being returned to the pool. Return |
| // it now. |
| close(); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| |
| /** |
| * Returns me to my pool. |
| */ |
| @Override |
| public synchronized void close() throws SQLException { |
| if (isClosedInternal()) { |
| // already closed |
| return; |
| } |
| |
| boolean isUnderlyingConectionClosed; |
| try { |
| isUnderlyingConectionClosed = getDelegateInternal().isClosed(); |
| } catch (final SQLException e) { |
| try { |
| _pool.invalidateObject(this); |
| } catch(final IllegalStateException ise) { |
| // pool is closed, so close the connection |
| passivate(); |
| getInnermostDelegate().close(); |
| } catch (final Exception ie) { |
| // DO NOTHING the original exception will be rethrown |
| } |
| throw new SQLException("Cannot close connection (isClosed check failed)", e); |
| } |
| |
| /* Can't set close before this code block since the connection needs to |
| * be open when validation runs. Can't set close after this code block |
| * since by then the connection will have been returned to the pool and |
| * may have been borrowed by another thread. Therefore, the close flag |
| * is set in passivate(). |
| */ |
| if (isUnderlyingConectionClosed) { |
| // Abnormal close: underlying connection closed unexpectedly, so we |
| // must destroy this proxy |
| try { |
| _pool.invalidateObject(this); |
| } catch(final IllegalStateException e) { |
| // pool is closed, so close the connection |
| passivate(); |
| getInnermostDelegate().close(); |
| } catch (final Exception e) { |
| throw new SQLException("Cannot close connection (invalidating pooled object failed)", e); |
| } |
| } else { |
| // Normal close: underlying connection is still open, so we |
| // simply need to return this proxy to the pool |
| try { |
| _pool.returnObject(this); |
| } catch(final IllegalStateException e) { |
| // pool is closed, so close the connection |
| passivate(); |
| getInnermostDelegate().close(); |
| } catch(final SQLException e) { |
| throw e; |
| } catch(final RuntimeException e) { |
| throw e; |
| } catch(final Exception e) { |
| throw new SQLException("Cannot close connection (return to pool failed)", e); |
| } |
| } |
| } |
| |
| /** |
| * Actually close my underlying {@link Connection}. |
| */ |
| @Override |
| public void reallyClose() throws SQLException { |
| if (_jmxName != null) { |
| try { |
| MBEAN_SERVER.unregisterMBean(_jmxName); |
| } catch (MBeanRegistrationException | InstanceNotFoundException e) { |
| // Ignore |
| } |
| } |
| |
| |
| if (validationPreparedStatement != null) { |
| try { |
| validationPreparedStatement.close(); |
| } catch (final SQLException sqle) { |
| // Ignore |
| } |
| } |
| |
| super.closeInternal(); |
| } |
| |
| |
| /** |
| * Expose the {@link #toString()} method via a bean getter so it can be read |
| * as a property via JMX. |
| */ |
| @Override |
| public String getToString() { |
| return toString(); |
| } |
| |
| /** |
| * Validates the connection, using the following algorithm: |
| * <ol> |
| * <li>If {@code fastFailValidation} (constructor argument) is {@code true} and |
| * this connection has previously thrown a fatal disconnection exception, |
| * a {@code SQLException} is thrown. </li> |
| * <li>If {@code sql} is null, the driver's |
| * #{@link Connection#isValid(int) isValid(timeout)} is called. |
| * If it returns {@code false}, {@code SQLException} is thrown; |
| * otherwise, this method returns successfully.</li> |
| * <li>If {@code sql} is not null, it is executed as a query and if the resulting |
| * {@code ResultSet} contains at least one row, this method returns |
| * successfully. If not, {@code SQLException} is thrown.</li> |
| * </ol> |
| * @param sql validation query |
| * @param timeout validation timeout |
| * @throws SQLException if validation fails or an SQLException occurs during validation |
| */ |
| public void validate(final String sql, int timeout) throws SQLException { |
| if (_fastFailValidation && _fatalSqlExceptionThrown) { |
| throw new SQLException(Utils.getMessage("poolableConnection.validate.fastFail")); |
| } |
| |
| if (sql == null || sql.length() == 0) { |
| if (timeout < 0) { |
| timeout = 0; |
| } |
| if (!isValid(timeout)) { |
| throw new SQLException("isValid() returned false"); |
| } |
| return; |
| } |
| |
| if (!sql.equals(lastValidationSql)) { |
| lastValidationSql = sql; |
| // Has to be the innermost delegate else the prepared statement will |
| // be closed when the pooled connection is passivated. |
| validationPreparedStatement = |
| getInnermostDelegateInternal().prepareStatement(sql); |
| } |
| |
| if (timeout > 0) { |
| validationPreparedStatement.setQueryTimeout(timeout); |
| } |
| |
| try (ResultSet rs = validationPreparedStatement.executeQuery()) { |
| if(!rs.next()) { |
| throw new SQLException("validationQuery didn't return a row"); |
| } |
| } catch (final SQLException sqle) { |
| throw sqle; |
| } |
| } |
| |
| /** |
| * Checks the SQLState of the input exception and any nested SQLExceptions it wraps. |
| * <p> |
| * If {@link #getDisconnectSqlCodes() disconnectSQLCodes} has been set, sql states |
| * are compared to those in the configured list of fatal exception codes. If this |
| * property is not set, codes are compared against the default codes in |
| * #{@link Utils.DISCONNECTION_SQL_CODES} and in this case anything starting with |
| * #{link Utils.DISCONNECTION_SQL_CODE_PREFIX} is considered a disconnection.</p> |
| * |
| * @param e SQLException to be examined |
| * @return true if the exception signals a disconnection |
| */ |
| private boolean isDisconnectionSqlException(final SQLException e) { |
| boolean fatalException = false; |
| final String sqlState = e.getSQLState(); |
| if (sqlState != null) { |
| fatalException = _disconnectionSqlCodes == null ? sqlState.startsWith(Utils.DISCONNECTION_SQL_CODE_PREFIX) |
| || Utils.DISCONNECTION_SQL_CODES.contains(sqlState) : _disconnectionSqlCodes.contains(sqlState); |
| if (!fatalException) { |
| if (e.getNextException() != null) { |
| fatalException = isDisconnectionSqlException(e.getNextException()); |
| } |
| } |
| } |
| return fatalException; |
| } |
| |
| @Override |
| protected void handleException(final SQLException e) throws SQLException { |
| _fatalSqlExceptionThrown |= isDisconnectionSqlException(e); |
| super.handleException(e); |
| } |
| } |
| |