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Apache Commons DBCP software implements Database Connection Pooling
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/*
* 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.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}.
*
* 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.
*
*
* 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.
*
*
* @param
* the Connection type
*
* @since 2.0
*/
public class DelegatingConnection extends AbandonedTrace implements Connection {
private static final Map EMPTY_FAILED_PROPERTIES = Collections
.emptyMap();
/** My delegate {@link Connection}. */
private volatile C connection;
private volatile boolean closed;
private 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);
}
}
protected void activate() {
closed = false;
setLastUsed();
if (connection instanceof DelegatingConnection) {
((DelegatingConnection) connection).activate();
}
}
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:
*
* - Call {@link #passivate()}
* - Call close (or the equivalent appropriate action) on the wrapped connection
* - Set {@code closed} to {@code false}
*
*/
@Override
public void close() throws SQLException {
if (!closed) {
closeInternal();
}
}
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;
}
}
/**
* Returns the state caching flag.
*
* @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 {@code DelegatingConnection}, returns it, otherwise recursively
* invokes this method on my delegate.
*
* Hence this method will return the first delegate that is not a {@code DelegatingConnection}, or {@code null} when
* no non-{@code DelegatingConnection} delegate can be found by traversing this chain.
*
*
* This method is useful when you may have nested {@code DelegatingConnection}s, and you want to make sure to obtain
* a "genuine" {@link Connection}.
*
*
* @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> 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 {@code SQLException}.
*
* @param The throwable type.
* @param e The SQLException
* @return the given {@code SQLException}
* @since 2.7.0
*/
protected T handleExceptionNoThrow(final T e) {
return e;
}
/**
* Initializes the given statement with this connection's settings.
*
* @param 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 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();
}
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())) {
return true;
}
if (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;
}
}
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 traceList = getTrace();
if (!Utils.isEmpty(traceList)) {
final List 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 the state caching flag.
*
* @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);
}
}
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 = connection.getSchema();
}
} 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> 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 unwrap(final Class iface) throws SQLException {
if (iface.isAssignableFrom(getClass())) {
return iface.cast(this);
}
if (iface.isAssignableFrom(connection.getClass())) {
return iface.cast(connection);
}
return connection.unwrap(iface);
}
}