/*
    * 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
    *
    *      https://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.commons.dbcp2;
  
  import java.sql.Array;
  import java.sql.Blob;
  import java.sql.CallableStatement;
  import java.sql.ClientInfoStatus;
  import java.sql.Clob;
  import java.sql.Connection;
  import java.sql.DatabaseMetaData;
  import java.sql.NClob;
  import java.sql.PreparedStatement;
  import java.sql.SQLClientInfoException;
  import java.sql.SQLException;
  import java.sql.SQLWarning;
  import java.sql.SQLXML;
  import java.sql.Savepoint;
  import java.sql.Statement;
  import java.sql.Struct;
  import java.time.Duration;
  import java.time.Instant;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  import java.util.concurrent.Executor;
  
  import org.apache.commons.dbcp2.managed.ManagedConnection;
  
  /**
   * A base delegating implementation of {@link Connection}.
   * <p>
   * All of the methods from the {@link Connection} interface simply check to see that the {@link Connection} is active,
   * and call the corresponding method on the "delegate" provided in my constructor.
   * </p>
   * <p>
   * Extends AbandonedTrace to implement Connection tracking and logging of code which created the Connection. Tracking
   * the Connection ensures that the AbandonedObjectPool can close this connection and recycle it if its pool of
   * connections is nearing exhaustion and this connection's last usage is older than the removeAbandonedTimeout.
   * </p>
   *
   * @param <C>
   *            the Connection type
   *
   * @since 2.0
   */
  public class DelegatingConnection<C extends Connection> extends AbandonedTrace implements Connection {
  
      private static final Map<String, ClientInfoStatus> EMPTY_FAILED_PROPERTIES = Collections
              .<String, ClientInfoStatus>emptyMap();
  
      /** My delegate {@link Connection}. */
      private volatile C connection;
  
      private volatile boolean closed;
      private volatile boolean cacheState = true;
      private Boolean cachedAutoCommit;
      private Boolean cachedReadOnly;
      private String cachedCatalog;
      private String cachedSchema;
      private Duration defaultQueryTimeoutDuration;
  
      /**
       * Creates a wrapper for the Connection which traces this Connection in the AbandonedObjectPool.
       *
       * @param connection the {@link Connection} to delegate all calls to, may be null (see {@link ManagedConnection}).
       */
      public DelegatingConnection(final C connection) {
          this.connection = connection;
      }
  
      @Override
      public void abort(final Executor executor) throws SQLException {
          try {
              Jdbc41Bridge.abort(connection, executor);
          } catch (final SQLException e) {
              handleException(e);
          }
      }
  
      /**
       * Marks this instance as used and delegates to a wrapped {@link DelegatingConnection#activate()}.
       */
     protected void activate() {
         closed = false;
         setLastUsed();
         if (connection instanceof DelegatingConnection) {
             ((DelegatingConnection<?>) connection).activate();
         }
     }
 
     /**
      * Throws a SQLException if this connection is not open.
      *
      * @throws SQLException Thrown if this connection is not open.
      */
     protected void checkOpen() throws SQLException {
         if (closed) {
             if (null != connection) {
                 String label;
                 try {
                     label = connection.toString();
                 } catch (final Exception e) {
                     // leave label empty
                     label = "";
                 }
                 throw new SQLException("Connection " + label + " is closed.");
             }
             throw new SQLException("Connection is null.");
         }
     }
 
     /**
      * Clears the cached state. Call when you know that the underlying connection may have been accessed
      * directly.
      */
     public void clearCachedState() {
         cachedAutoCommit = null;
         cachedReadOnly = null;
         cachedSchema = null;
         cachedCatalog = null;
         if (connection instanceof DelegatingConnection) {
             ((DelegatingConnection<?>) connection).clearCachedState();
         }
     }
 
     @Override
     public void clearWarnings() throws SQLException {
         checkOpen();
         try {
             connection.clearWarnings();
         } catch (final SQLException e) {
             handleException(e);
         }
     }
 
     /**
      * Closes the underlying connection, and close any Statements that were not explicitly closed. Sub-classes that
      * override this method must:
      * <ol>
      * <li>Call {@link #passivate()}</li>
      * <li>Call close (or the equivalent appropriate action) on the wrapped connection</li>
      * <li>Set {@code closed} to {@code false}</li>
      * </ol>
      */
     @Override
     public void close() throws SQLException {
         if (!closed) {
             closeInternal();
         }
     }
 
     /**
      * Closes the underlying connection for {@link #close()}.
      *
      * @throws SQLException SQLException if a database access error occurs.
      */
     protected final void closeInternal() throws SQLException {
         try {
             passivate();
         } finally {
             if (connection != null) {
                 boolean connectionIsClosed;
                 try {
                     connectionIsClosed = connection.isClosed();
                 } catch (final SQLException e) {
                     // not sure what the state is, so assume the connection is open.
                     connectionIsClosed = false;
                 }
                 try {
                     // DBCP-512: Avoid exceptions when closing a connection in multi-threaded use case.
                     // Avoid closing again, which should be a no-op, but some drivers like H2 throw an exception when
                     // closing from multiple threads.
                     if (!connectionIsClosed) {
                         connection.close();
                     }
                 } finally {
                     closed = true;
                 }
             } else {
                 closed = true;
             }
         }
     }
 
     @Override
     public void commit() throws SQLException {
         checkOpen();
         try {
             connection.commit();
         } catch (final SQLException e) {
             handleException(e);
         }
     }
 
     @Override
     public Array createArrayOf(final String typeName, final Object[] elements) throws SQLException {
         checkOpen();
         try {
             return connection.createArrayOf(typeName, elements);
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public Blob createBlob() throws SQLException {
         checkOpen();
         try {
             return connection.createBlob();
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public Clob createClob() throws SQLException {
         checkOpen();
         try {
             return connection.createClob();
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public NClob createNClob() throws SQLException {
         checkOpen();
         try {
             return connection.createNClob();
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public SQLXML createSQLXML() throws SQLException {
         checkOpen();
         try {
             return connection.createSQLXML();
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public Statement createStatement() throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingStatement(this, connection.createStatement()));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public Statement createStatement(final int resultSetType, final int resultSetConcurrency) throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingStatement(this, connection.createStatement(resultSetType, resultSetConcurrency)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public Statement createStatement(final int resultSetType, final int resultSetConcurrency,
         final int resultSetHoldability) throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingStatement(this,
                 connection.createStatement(resultSetType, resultSetConcurrency, resultSetHoldability)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public Struct createStruct(final String typeName, final Object[] attributes) throws SQLException {
         checkOpen();
         try {
             return connection.createStruct(typeName, attributes);
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public boolean getAutoCommit() throws SQLException {
         checkOpen();
         if (cacheState && cachedAutoCommit != null) {
             return cachedAutoCommit;
         }
         try {
             cachedAutoCommit = connection.getAutoCommit();
             return cachedAutoCommit;
         } catch (final SQLException e) {
             handleException(e);
             return false;
         }
     }
 
     /**
      * Gets whether to cache properties. The cached properties are:
      * <ul>
      * <li>auto-commit</li>
      * <li>catalog</li>
      * <li>schema</li>
      * <li>read-only</li>
      * </ul>
      *
      * @return the state caching flag
      */
     public boolean getCacheState() {
         return cacheState;
     }
 
     @Override
     public String getCatalog() throws SQLException {
         checkOpen();
         if (cacheState && cachedCatalog != null) {
             return cachedCatalog;
         }
         try {
             cachedCatalog = connection.getCatalog();
             return cachedCatalog;
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public Properties getClientInfo() throws SQLException {
         checkOpen();
         try {
             return connection.getClientInfo();
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public String getClientInfo(final String name) throws SQLException {
         checkOpen();
         try {
             return connection.getClientInfo(name);
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     /**
      * Gets the default query timeout that will be used for {@link Statement}s created from this connection.
      * {@code null} means that the driver default will be used.
      *
      * @return query timeout limit in seconds; zero means there is no limit.
      * @deprecated Use {@link #getDefaultQueryTimeoutDuration()}.
      */
     @Deprecated
     public Integer getDefaultQueryTimeout() {
         return defaultQueryTimeoutDuration == null ? null : (int) defaultQueryTimeoutDuration.getSeconds();
     }
 
     /**
      * Gets the default query timeout that will be used for {@link Statement}s created from this connection.
      * {@code null} means that the driver default will be used.
      *
      * @return query timeout limit; zero means there is no limit.
      * @since 2.10.0
      */
     public Duration getDefaultQueryTimeoutDuration() {
         return defaultQueryTimeoutDuration;
     }
 
     /**
      * Returns my underlying {@link Connection}.
      *
      * @return my underlying {@link Connection}.
      */
     public C getDelegate() {
         return getDelegateInternal();
     }
 
     /**
      * Gets the delegate connection.
      *
      * @return the delegate connection.
      */
     protected final C getDelegateInternal() {
         return connection;
     }
 
     @Override
     public int getHoldability() throws SQLException {
         checkOpen();
         try {
             return connection.getHoldability();
         } catch (final SQLException e) {
             handleException(e);
             return 0;
         }
     }
 
     /**
      * If my underlying {@link Connection} is not a {@link DelegatingConnection}, returns it, otherwise recursively
      * invokes this method on my delegate.
      * <p>
      * Hence this method will return the first delegate that is not a {@link DelegatingConnection}, or {@code null} when
      * no non-{@link DelegatingConnection} delegate can be found by traversing this chain.
      * </p>
      * <p>
      * This method is useful when you may have nested {@link DelegatingConnection}s, and you want to make sure to obtain
      * a "genuine" {@link Connection}.
      * </p>
      *
      * @return innermost delegate.
      */
     public Connection getInnermostDelegate() {
         return getInnermostDelegateInternal();
     }
 
     /**
      * Although this method is public, it is part of the internal API and should not be used by clients. The signature
      * of this method may change at any time including in ways that break backwards compatibility.
      *
      * @return innermost delegate.
      */
     @SuppressWarnings("resource")
     public final Connection getInnermostDelegateInternal() {
         Connection conn = connection;
         while (conn instanceof DelegatingConnection) {
             conn = ((DelegatingConnection<?>) conn).getDelegateInternal();
             if (this == conn) {
                 return null;
             }
         }
         return conn;
     }
 
     @Override
     public DatabaseMetaData getMetaData() throws SQLException {
         checkOpen();
         try {
             return new DelegatingDatabaseMetaData(this, connection.getMetaData());
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public int getNetworkTimeout() throws SQLException {
         checkOpen();
         try {
             return Jdbc41Bridge.getNetworkTimeout(connection);
         } catch (final SQLException e) {
             handleException(e);
             return 0;
         }
     }
 
     @Override
     public String getSchema() throws SQLException {
         checkOpen();
         if (cacheState && cachedSchema != null) {
             return cachedSchema;
         }
         try {
             cachedSchema = Jdbc41Bridge.getSchema(connection);
             return cachedSchema;
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public int getTransactionIsolation() throws SQLException {
         checkOpen();
         try {
             return connection.getTransactionIsolation();
         } catch (final SQLException e) {
             handleException(e);
             return -1;
         }
     }
 
     @Override
     public Map<String, Class<?>> getTypeMap() throws SQLException {
         checkOpen();
         try {
             return connection.getTypeMap();
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public SQLWarning getWarnings() throws SQLException {
         checkOpen();
         try {
             return connection.getWarnings();
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     /**
      * Handles the given exception by throwing it.
      *
      * @param e the exception to throw.
      * @throws SQLException the exception to throw.
      */
     protected void handleException(final SQLException e) throws SQLException {
         throw e;
     }
 
     /**
      * Handles the given {@link SQLException}.
      *
      * @param <T> The throwable type.
      * @param e   The SQLException
      * @return the given {@link SQLException}
      * @since 2.7.0
      */
     protected <T extends Throwable> T handleExceptionNoThrow(final T e) {
         return e;
     }
 
     /**
      * Initializes the given statement with this connection's settings.
      *
      * @param <T> The DelegatingStatement type.
      * @param delegatingStatement The DelegatingStatement to initialize.
      * @return The given DelegatingStatement.
      * @throws SQLException if a database access error occurs, this method is called on a closed Statement.
      */
     private <T extends DelegatingStatement> T init(final T delegatingStatement) throws SQLException {
         if (defaultQueryTimeoutDuration != null && defaultQueryTimeoutDuration.getSeconds() != delegatingStatement.getQueryTimeout()) {
             delegatingStatement.setQueryTimeout((int) defaultQueryTimeoutDuration.getSeconds());
         }
         return delegatingStatement;
     }
 
     /**
      * Compares innermost delegate to the given connection.
      *
      * @param c
      *            connection to compare innermost delegate with
      * @return true if innermost delegate equals {@code c}
      */
     @SuppressWarnings("resource")
     public boolean innermostDelegateEquals(final Connection c) {
         final Connection innerCon = getInnermostDelegateInternal();
         if (innerCon == null) {
             return c == null;
         }
         return innerCon.equals(c);
     }
 
     @Override
     public boolean isClosed() throws SQLException {
         return closed || connection == null || connection.isClosed();
     }
 
     /**
      * Tests the raw internal closed state.
      *
      * @return the raw internal closed state.
      */
     protected boolean isClosedInternal() {
         return closed;
     }
 
     @Override
     public boolean isReadOnly() throws SQLException {
         checkOpen();
         if (cacheState && cachedReadOnly != null) {
             return cachedReadOnly;
         }
         try {
             cachedReadOnly = connection.isReadOnly();
             return cachedReadOnly;
         } catch (final SQLException e) {
             handleException(e);
             return false;
         }
     }
 
     /**
      * Tests if the connection has not been closed and is still valid.
      *
      * @param timeout The duration to wait for the database operation used to validate the connection to complete.
      * @return See {@link Connection#isValid(int)}.
      * @throws SQLException See {@link Connection#isValid(int)}.
      * @see Connection#isValid(int)
      * @since 2.10.0
      */
     public boolean isValid(final Duration timeout) throws SQLException {
         if (isClosed()) {
             return false;
         }
         try {
             return connection.isValid((int) timeout.getSeconds());
         } catch (final SQLException e) {
             handleException(e);
             return false;
         }
     }
 
     /**
      * @deprecated Use {@link #isValid(Duration)}.
      */
     @Override
     @Deprecated
     public boolean isValid(final int timeoutSeconds) throws SQLException {
         return isValid(Duration.ofSeconds(timeoutSeconds));
     }
 
     @Override
     public boolean isWrapperFor(final Class<?> iface) throws SQLException {
         if (iface.isAssignableFrom(getClass()) || iface.isAssignableFrom(connection.getClass())) {
             return true;
         }
         return connection.isWrapperFor(iface);
     }
 
     @Override
     public String nativeSQL(final String sql) throws SQLException {
         checkOpen();
         try {
             return connection.nativeSQL(sql);
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     /**
      * Clears the list of objects being traced by this object.
      *
      * @throws SQLException Thrown if not all traced objects were closed.
      */
     protected void passivate() throws SQLException {
         // The JDBC specification requires that a Connection close any open
         // Statements when it is closed.
         // DBCP-288. Not all the traced objects will be statements
         final List<AbandonedTrace> traceList = getTrace();
         if (!Utils.isEmpty(traceList)) {
             final List<Exception> thrownList = new ArrayList<>();
             traceList.forEach(trace -> trace.close(thrownList::add));
             clearTrace();
             if (!thrownList.isEmpty()) {
                 throw new SQLExceptionList(thrownList);
             }
         }
         setLastUsed(Instant.EPOCH);
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public CallableStatement prepareCall(final String sql) throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingCallableStatement(this, connection.prepareCall(sql)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public CallableStatement prepareCall(final String sql, final int resultSetType, final int resultSetConcurrency)
         throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingCallableStatement(this,
                 connection.prepareCall(sql, resultSetType, resultSetConcurrency)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public CallableStatement prepareCall(final String sql, final int resultSetType, final int resultSetConcurrency,
         final int resultSetHoldability) throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingCallableStatement(this,
                 connection.prepareCall(sql, resultSetType, resultSetConcurrency, resultSetHoldability)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public PreparedStatement prepareStatement(final String sql) throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingPreparedStatement(this, connection.prepareStatement(sql)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public PreparedStatement prepareStatement(final String sql, final int autoGeneratedKeys) throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingPreparedStatement(this, connection.prepareStatement(sql, autoGeneratedKeys)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public PreparedStatement prepareStatement(final String sql, final int resultSetType, final int resultSetConcurrency)
         throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingPreparedStatement(this,
                 connection.prepareStatement(sql, resultSetType, resultSetConcurrency)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public PreparedStatement prepareStatement(final String sql, final int resultSetType, final int resultSetConcurrency,
         final int resultSetHoldability) throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingPreparedStatement(this,
                 connection.prepareStatement(sql, resultSetType, resultSetConcurrency, resultSetHoldability)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public PreparedStatement prepareStatement(final String sql, final int[] columnIndexes) throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingPreparedStatement(this, connection.prepareStatement(sql, columnIndexes)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @SuppressWarnings("resource") // Caller is responsible for closing the resource.
     @Override
     public PreparedStatement prepareStatement(final String sql, final String[] columnNames) throws SQLException {
         checkOpen();
         try {
             return init(new DelegatingPreparedStatement(this, connection.prepareStatement(sql, columnNames)));
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public void releaseSavepoint(final Savepoint savepoint) throws SQLException {
         checkOpen();
         try {
             connection.releaseSavepoint(savepoint);
         } catch (final SQLException e) {
             handleException(e);
         }
     }
 
     @Override
     public void rollback() throws SQLException {
         checkOpen();
         try {
             connection.rollback();
         } catch (final SQLException e) {
             handleException(e);
         }
     }
 
     @Override
     public void rollback(final Savepoint savepoint) throws SQLException {
         checkOpen();
         try {
             connection.rollback(savepoint);
         } catch (final SQLException e) {
             handleException(e);
         }
     }
 
     @Override
     public void setAutoCommit(final boolean autoCommit) throws SQLException {
         checkOpen();
         try {
             connection.setAutoCommit(autoCommit);
             if (cacheState) {
                 cachedAutoCommit = connection.getAutoCommit();
             }
         } catch (final SQLException e) {
             cachedAutoCommit = null;
             handleException(e);
         }
     }
 
     /**
      * Sets whether to cache properties. The cached properties are:
      * <ul>
      * <li>auto-commit</li>
      * <li>catalog</li>
      * <li>schema</li>
      * <li>read-only</li>
      * </ul>
      *
      * @param cacheState The new value for the state caching flag
      */
     public void setCacheState(final boolean cacheState) {
         this.cacheState = cacheState;
     }
 
     @Override
     public void setCatalog(final String catalog) throws SQLException {
         checkOpen();
         try {
             connection.setCatalog(catalog);
             if (cacheState) {
                 cachedCatalog = connection.getCatalog();
             }
         } catch (final SQLException e) {
             cachedCatalog = null;
             handleException(e);
         }
     }
 
     @Override
     public void setClientInfo(final Properties properties) throws SQLClientInfoException {
         try {
             checkOpen();
             connection.setClientInfo(properties);
         } catch (final SQLClientInfoException e) {
             throw e;
         } catch (final SQLException e) {
             throw new SQLClientInfoException("Connection is closed.", EMPTY_FAILED_PROPERTIES, e);
         }
     }
 
     @Override
     public void setClientInfo(final String name, final String value) throws SQLClientInfoException {
         try {
             checkOpen();
             connection.setClientInfo(name, value);
         } catch (final SQLClientInfoException e) {
             throw e;
         } catch (final SQLException e) {
             throw new SQLClientInfoException("Connection is closed.", EMPTY_FAILED_PROPERTIES, e);
         }
     }
 
     /**
      * Sets the raw internal closed state.
      *
      * @param closed the raw internal closed state.
      */
     protected void setClosedInternal(final boolean closed) {
         this.closed = closed;
     }
 
     /**
      * Sets the default query timeout that will be used for {@link Statement}s created from this connection.
      * {@code null} means that the driver default will be used.
      *
      * @param defaultQueryTimeoutDuration
      *            the new query timeout limit Duration; zero means there is no limit.
      * @since 2.10.0
      */
     public void setDefaultQueryTimeout(final Duration defaultQueryTimeoutDuration) {
         this.defaultQueryTimeoutDuration = defaultQueryTimeoutDuration;
     }
 
     /**
      * Sets the default query timeout that will be used for {@link Statement}s created from this connection.
      * {@code null} means that the driver default will be used.
      *
      * @param defaultQueryTimeoutSeconds
      *            the new query timeout limit in seconds; zero means there is no limit.
      * @deprecated Use {@link #setDefaultQueryTimeout(Duration)}.
      */
     @Deprecated
     public void setDefaultQueryTimeout(final Integer defaultQueryTimeoutSeconds) {
         this.defaultQueryTimeoutDuration = defaultQueryTimeoutSeconds == null ? null : Duration.ofSeconds(defaultQueryTimeoutSeconds);
     }
 
     /**
      * Sets my delegate.
      *
      * @param connection
      *            my delegate, may be null.
      */
     public void setDelegate(final C connection) {
         this.connection = connection;
     }
 
     @Override
     public void setHoldability(final int holdability) throws SQLException {
         checkOpen();
         try {
             connection.setHoldability(holdability);
         } catch (final SQLException e) {
             handleException(e);
         }
     }
 
     @Override
     public void setNetworkTimeout(final Executor executor, final int milliseconds) throws SQLException {
         checkOpen();
         try {
             Jdbc41Bridge.setNetworkTimeout(connection, executor, milliseconds);
         } catch (final SQLException e) {
             handleException(e);
         }
     }
 
     @Override
     public void setReadOnly(final boolean readOnly) throws SQLException {
         checkOpen();
         try {
             connection.setReadOnly(readOnly);
             if (cacheState) {
                 cachedReadOnly = connection.isReadOnly();
             }
         } catch (final SQLException e) {
             cachedReadOnly = null;
             handleException(e);
         }
     }
 
     @Override
     public Savepoint setSavepoint() throws SQLException {
         checkOpen();
         try {
             return connection.setSavepoint();
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public Savepoint setSavepoint(final String name) throws SQLException {
         checkOpen();
         try {
             return connection.setSavepoint(name);
         } catch (final SQLException e) {
             handleException(e);
             return null;
         }
     }
 
     @Override
     public void setSchema(final String schema) throws SQLException {
         checkOpen();
         try {
             Jdbc41Bridge.setSchema(connection, schema);
             if (cacheState) {
                 cachedSchema = Jdbc41Bridge.getSchema(connection);
             }
         } catch (final SQLException e) {
             cachedSchema = null;
             handleException(e);
         }
     }
 
     @Override
     public void setTransactionIsolation(final int level) throws SQLException {
         checkOpen();
         try {
             connection.setTransactionIsolation(level);
         } catch (final SQLException e) {
             handleException(e);
         }
     }
 
     @Override
     public void setTypeMap(final Map<String, Class<?>> map) throws SQLException {
         checkOpen();
         try {
             connection.setTypeMap(map);
         } catch (final SQLException e) {
             handleException(e);
         }
     }
 
     /**
      * Returns a string representation of the metadata associated with the innermost delegate connection.
      */
     @SuppressWarnings("resource")
     @Override
     public synchronized String toString() {
         String str = null;
 
         final Connection conn = this.getInnermostDelegateInternal();
         if (conn != null) {
             try {
                 if (conn.isClosed()) {
                     str = "connection is closed";
                 } else {
                     final StringBuilder sb = new StringBuilder();
                     sb.append(hashCode());
                     final DatabaseMetaData meta = conn.getMetaData();
                     if (meta != null) {
                         sb.append(", URL=");
                         sb.append(meta.getURL());
                         sb.append(", ");
                         sb.append(meta.getDriverName());
                         str = sb.toString();
                     }
                 }
             } catch (final SQLException ignored) {
                 // Ignore
             }
         }
         return str != null ? str : super.toString();
     }
 
     @Override
     public <T> T unwrap(final Class<T> iface) throws SQLException {
         if (iface.isAssignableFrom(getClass())) {
             return iface.cast(this);
         }
         if (iface.isAssignableFrom(connection.getClass())) {
             return iface.cast(connection);
         }
         return connection.unwrap(iface);
     }
 }