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Java JDBC 4.2 (JRE 8+) driver for Redshift database
/*
* Copyright (c) 2004, PostgreSQL Global Development Group
* See the LICENSE file in the project root for more information.
*/
package com.amazon.redshift.ds;
import com.amazon.redshift.ds.common.BaseDataSource;
import com.amazon.redshift.util.GT;
import com.amazon.redshift.util.RedshiftException;
import com.amazon.redshift.util.RedshiftState;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Stack;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import javax.naming.NamingException;
import javax.naming.Reference;
import javax.naming.StringRefAddr;
import javax.sql.ConnectionEvent;
import javax.sql.ConnectionEventListener;
import javax.sql.DataSource;
import javax.sql.PooledConnection;
/**
* DataSource which uses connection pooling. Don't use this if your
* server/middleware vendor provides a connection pooling implementation which interfaces with the
* Redshift ConnectionPoolDataSource implementation! This class is provided as a
* convenience, but the JDBC Driver is really not supposed to handle the connection pooling
* algorithm. Instead, the server or middleware product is supposed to handle the mechanics of
* connection pooling, and use the Redshift implementation of ConnectionPoolDataSource to provide
* the connections to pool.
*
*
* If you're sure you want to use this, then you must set the properties dataSourceName,
* databaseName, user, and password (if required for the user). The settings for serverName,
* portNumber, initialConnections, and maxConnections are optional. Note that only connections
* for the default user will be pooled! Connections for other users will be normal non-pooled
* connections, and will not count against the maximum pool size limit.
*
*
*
* If you put this DataSource in JNDI, and access it from different JVMs (or otherwise load this
* class from different ClassLoaders), you'll end up with one pool per ClassLoader or VM. This is
* another area where a server-specific implementation may provide advanced features, such as using
* a single pool across all VMs in a cluster.
*
*
*
* This implementation supports JDK 1.5 and higher.
*
*
* @author Aaron Mulder ([email protected])
*
* @deprecated Since 42.0.0, instead of this class you should use a fully featured connection pool
* like HikariCP, vibur-dbcp, commons-dbcp, c3p0, etc.
*/
@Deprecated
public class RedshiftPoolingDataSource extends BaseDataSource implements DataSource {
protected static ConcurrentMap dataSources =
new ConcurrentHashMap();
public static RedshiftPoolingDataSource getDataSource(String name) {
return dataSources.get(name);
}
// Additional Data Source properties
protected String dataSourceName; // Must be protected for subclasses to sync updates to it
private int initialConnections = 0;
private int maxConnections = 0;
// State variables
private boolean initialized = false;
private Stack available = new Stack();
private Stack used = new Stack();
private Object lock = new Object();
private RedshiftConnectionPoolDataSource source;
/**
* Gets a description of this DataSource.
*/
public String getDescription() {
return "Pooling DataSource '" + dataSourceName + " from " + com.amazon.redshift.util.DriverInfo.DRIVER_FULL_NAME;
}
/**
* Ensures the DataSource properties are not changed after the DataSource has been used.
*
* @throws IllegalStateException The Server Name cannot be changed after the DataSource has been
* used.
*/
public void setServerName(String serverName) {
if (initialized) {
throw new IllegalStateException(
"Cannot set Data Source properties after DataSource has been used");
}
super.setServerName(serverName);
}
/**
* Ensures the DataSource properties are not changed after the DataSource has been used.
*
* @throws IllegalStateException The Database Name cannot be changed after the DataSource has been
* used.
*/
public void setDatabaseName(String databaseName) {
if (initialized) {
throw new IllegalStateException(
"Cannot set Data Source properties after DataSource has been used");
}
super.setDatabaseName(databaseName);
}
/**
* Ensures the DataSource properties are not changed after the DataSource has been used.
*
* @throws IllegalStateException The User cannot be changed after the DataSource has been used.
*/
public void setUser(String user) {
if (initialized) {
throw new IllegalStateException(
"Cannot set Data Source properties after DataSource has been used");
}
super.setUser(user);
}
/**
* Ensures the DataSource properties are not changed after the DataSource has been used.
*
* @throws IllegalStateException The Password cannot be changed after the DataSource has been
* used.
*/
public void setPassword(String password) {
if (initialized) {
throw new IllegalStateException(
"Cannot set Data Source properties after DataSource has been used");
}
super.setPassword(password);
}
/**
* Ensures the DataSource properties are not changed after the DataSource has been used.
*
* @throws IllegalStateException The Port Number cannot be changed after the DataSource has been
* used.
*/
public void setPortNumber(int portNumber) {
if (initialized) {
throw new IllegalStateException(
"Cannot set Data Source properties after DataSource has been used");
}
super.setPortNumber(portNumber);
}
/**
* Gets the number of connections that will be created when this DataSource is initialized. If you
* do not call initialize explicitly, it will be initialized the first time a connection is drawn
* from it.
*
* @return number of connections that will be created when this DataSource is initialized
*/
public int getInitialConnections() {
return initialConnections;
}
/**
* Sets the number of connections that will be created when this DataSource is initialized. If you
* do not call initialize explicitly, it will be initialized the first time a connection is drawn
* from it.
*
* @param initialConnections number of initial connections
* @throws IllegalStateException The Initial Connections cannot be changed after the DataSource
* has been used.
*/
public void setInitialConnections(int initialConnections) {
if (initialized) {
throw new IllegalStateException(
"Cannot set Data Source properties after DataSource has been used");
}
this.initialConnections = initialConnections;
}
/**
* Gets the maximum number of connections that the pool will allow. If a request comes in and this
* many connections are in use, the request will block until a connection is available. Note that
* connections for a user other than the default user will not be pooled and don't count against
* this limit.
*
* @return The maximum number of pooled connection allowed, or 0 for no maximum.
*/
public int getMaxConnections() {
return maxConnections;
}
/**
* Sets the maximum number of connections that the pool will allow. If a request comes in and this
* many connections are in use, the request will block until a connection is available. Note that
* connections for a user other than the default user will not be pooled and don't count against
* this limit.
*
* @param maxConnections The maximum number of pooled connection to allow, or 0 for no maximum.
* @throws IllegalStateException The Maximum Connections cannot be changed after the DataSource
* has been used.
*/
public void setMaxConnections(int maxConnections) {
if (initialized) {
throw new IllegalStateException(
"Cannot set Data Source properties after DataSource has been used");
}
this.maxConnections = maxConnections;
}
/**
* Gets the name of this DataSource. This uniquely identifies the DataSource. You cannot use more
* than one DataSource in the same VM with the same name.
*
* @return name of this DataSource
*/
public String getDataSourceName() {
return dataSourceName;
}
/**
* Sets the name of this DataSource. This is required, and uniquely identifies the DataSource. You
* cannot create or use more than one DataSource in the same VM with the same name.
*
* @param dataSourceName datasource name
* @throws IllegalStateException The Data Source Name cannot be changed after the DataSource has
* been used.
* @throws IllegalArgumentException Another PoolingDataSource with the same dataSourceName already
* exists.
*/
public void setDataSourceName(String dataSourceName) {
if (initialized) {
throw new IllegalStateException(
"Cannot set Data Source properties after DataSource has been used");
}
if (this.dataSourceName != null && dataSourceName != null
&& dataSourceName.equals(this.dataSourceName)) {
return;
}
RedshiftPoolingDataSource previous = dataSources.putIfAbsent(dataSourceName, this);
if (previous != null) {
throw new IllegalArgumentException(
"DataSource with name '" + dataSourceName + "' already exists!");
}
if (this.dataSourceName != null) {
dataSources.remove(this.dataSourceName);
}
this.dataSourceName = dataSourceName;
}
/**
* Initializes this DataSource. If the initialConnections is greater than zero, that number of
* connections will be created. After this method is called, the DataSource properties cannot be
* changed. If you do not call this explicitly, it will be called the first time you get a
* connection from the DataSource.
*
* @throws SQLException Occurs when the initialConnections is greater than zero, but the
* DataSource is not able to create enough physical connections.
*/
public void initialize() throws SQLException {
synchronized (lock) {
source = createConnectionPool();
try {
source.initializeFrom(this);
} catch (Exception e) {
throw new RedshiftException(GT.tr("Failed to setup DataSource."), RedshiftState.UNEXPECTED_ERROR,
e);
}
while (available.size() < initialConnections) {
available.push(source.getPooledConnection());
}
initialized = true;
}
}
protected boolean isInitialized() {
return initialized;
}
/**
* Creates the appropriate ConnectionPool to use for this DataSource.
*
* @return appropriate ConnectionPool to use for this DataSource
*/
protected RedshiftConnectionPoolDataSource createConnectionPool() {
return new RedshiftConnectionPoolDataSource();
}
/**
* Gets a non-pooled connection, unless the user and password are the same as the default
* values for this connection pool.
*
* @return A pooled connection.
* @throws SQLException Occurs when no pooled connection is available, and a new physical
* connection cannot be created.
*/
public Connection getConnection(String user, String password) throws SQLException {
// If this is for the default user/password, use a pooled connection
if (user == null || (user.equals(getUser()) && ((password == null && getPassword() == null)
|| (password != null && password.equals(getPassword()))))) {
return getConnection();
}
// Otherwise, use a non-pooled connection
if (!initialized) {
initialize();
}
return super.getConnection(user, password);
}
/**
* Gets a connection from the connection pool.
*
* @return A pooled connection.
* @throws SQLException Occurs when no pooled connection is available, and a new physical
* connection cannot be created.
*/
public Connection getConnection() throws SQLException {
if (!initialized) {
initialize();
}
return getPooledConnection();
}
/**
* Closes this DataSource, and all the pooled connections, whether in use or not.
*/
public void close() {
synchronized (lock) {
while (!available.isEmpty()) {
PooledConnection pci = available.pop();
try {
pci.close();
} catch (SQLException e) {
}
}
available = null;
while (!used.isEmpty()) {
PooledConnection pci = used.pop();
pci.removeConnectionEventListener(connectionEventListener);
try {
pci.close();
} catch (SQLException e) {
}
}
used = null;
}
removeStoredDataSource();
}
protected void removeStoredDataSource() {
dataSources.remove(dataSourceName);
}
protected void addDataSource(String dataSourceName) {
dataSources.put(dataSourceName, this);
}
/**
* Gets a connection from the pool. Will get an available one if present, or create a new one if
* under the max limit. Will block if all used and a new one would exceed the max.
*/
private Connection getPooledConnection() throws SQLException {
PooledConnection pc = null;
synchronized (lock) {
if (available == null) {
throw new RedshiftException(GT.tr("DataSource has been closed."),
RedshiftState.CONNECTION_DOES_NOT_EXIST);
}
while (true) {
if (!available.isEmpty()) {
pc = available.pop();
used.push(pc);
break;
}
if (maxConnections == 0 || used.size() < maxConnections) {
pc = source.getPooledConnection();
used.push(pc);
break;
} else {
try {
// Wake up every second at a minimum
lock.wait(1000L);
} catch (InterruptedException e) {
}
}
}
}
pc.addConnectionEventListener(connectionEventListener);
return pc.getConnection();
}
/**
* Notified when a pooled connection is closed, or a fatal error occurs on a pooled connection.
* This is the only way connections are marked as unused.
*/
private ConnectionEventListener connectionEventListener = new ConnectionEventListener() {
public void connectionClosed(ConnectionEvent event) {
((PooledConnection) event.getSource()).removeConnectionEventListener(this);
synchronized (lock) {
if (available == null) {
return; // DataSource has been closed
}
boolean removed = used.remove(event.getSource());
if (removed) {
available.push((PooledConnection) event.getSource());
// There's now a new connection available
lock.notify();
} else {
// a connection error occurred
}
}
}
/**
* This is only called for fatal errors, where the physical connection is useless afterward and
* should be removed from the pool.
*/
public void connectionErrorOccurred(ConnectionEvent event) {
((PooledConnection) event.getSource()).removeConnectionEventListener(this);
synchronized (lock) {
if (available == null) {
return; // DataSource has been closed
}
used.remove(event.getSource());
// We're now at least 1 connection under the max
lock.notify();
}
}
};
/**
* Adds custom properties for this DataSource to the properties defined in the superclass.
*/
public Reference getReference() throws NamingException {
Reference ref = super.getReference();
ref.add(new StringRefAddr("dataSourceName", dataSourceName));
if (initialConnections > 0) {
ref.add(new StringRefAddr("initialConnections", Integer.toString(initialConnections)));
}
if (maxConnections > 0) {
ref.add(new StringRefAddr("maxConnections", Integer.toString(maxConnections)));
}
return ref;
}
public boolean isWrapperFor(Class iface) throws SQLException {
return iface.isAssignableFrom(getClass());
}
public T unwrap(Class iface) throws SQLException {
if (iface.isAssignableFrom(getClass())) {
return iface.cast(this);
}
throw new SQLException("Cannot unwrap to " + iface.getName());
}
}