org.hsqldb.jdbc
Class JDBCDataSource

java.lang.Object
  extended by org.hsqldb.jdbc.JDBCDataSource
All Implemented Interfaces:
Serializable, Wrapper, Referenceable, CommonDataSource, DataSource

public class JDBCDataSource
extends Object
implements Serializable, Referenceable, DataSource, CommonDataSource, Wrapper

A factory for connections to the physical data source that this DataSource object represents. An alternative to the DriverManager facility, a DataSource object is the preferred means of getting a connection. An object that implements the DataSource interface will typically be registered with a naming service based on the JavaTM Naming and Directory (JNDI) API.

The DataSource interface is implemented by a driver vendor. There are three types of implementations:

  1. Basic implementation -- produces a standard Connection object
  2. Connection pooling implementation -- produces a Connection object that will automatically participate in connection pooling. This implementation works with a middle-tier connection pooling manager.
  3. Distributed transaction implementation -- produces a Connection object that may be used for distributed transactions and almost always participates in connection pooling. This implementation works with a middle-tier transaction manager and almost always with a connection pooling manager.

A DataSource object has properties that can be modified when necessary. For example, if the data source is moved to a different server, the property for the server can be changed. The benefit is that because the data source's properties can be changed, any code accessing that data source does not need to be changed.

A driver that is accessed via a DataSource object does not register itself with the DriverManager. Rather, a DataSource object is retrieved though a lookup operation and then used to create a Connection object. With a basic implementation, the connection obtained through a DataSource object is identical to a connection obtained through the DriverManager facility.

Since:
JDK 1.4
Author:
deforest@users, boucherb@users
See Also:
Serialized Form

Constructor Summary
JDBCDataSource()
          Constructor
 
Method Summary
 Connection getConnection()
          Attempts to establish a connection with the data source that this DataSource object represents.
 Connection getConnection(String username, String password)
          Attempts to establish a connection with the data source that this DataSource object represents.
 String getDatabase()
          Retrieves the jdbc database connection url attribute.
 int getLoginTimeout()
          Gets the maximum time in seconds that this data source can wait while attempting to connect to a database.
 PrintWriter getLogWriter()
          Retrieves the log writer for this DataSource object.
 Reference getReference()
           
 String getUser()
          Retrieves the user ID for the connection.
 boolean isWrapperFor(Class<?> iface)
          Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does.
 void setDatabase(String database)
          Assigns the value of this object's jdbc database connection url attribute.
 void setLoginTimeout(int seconds)
          Sets the maximum time in seconds that this data source will wait while attempting to connect to a database.
 void setLogWriter(PrintWriter logWriter)
          Sets the log writer for this DataSource object to the given java.io.PrintWriter object.
 void setPassword(String password)
          Sets the password to use for connecting to the database
 void setUser(String user)
          Sets the userid
<T> T
unwrap(Class<T> iface)
          Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

JDBCDataSource

public JDBCDataSource()
Constructor

Method Detail

getConnection

public Connection getConnection()
                         throws SQLException

Attempts to establish a connection with the data source that this DataSource object represents.

Specified by:
getConnection in interface DataSource
Returns:
a connection to the data source
Throws:
SQLException - if a database access error occurs

getConnection

public Connection getConnection(String username,
                                String password)
                         throws SQLException

Attempts to establish a connection with the data source that this DataSource object represents.

Specified by:
getConnection in interface DataSource
Parameters:
username - the database user on whose behalf the connection is being made
password - the user's password
Returns:
a connection to the data source
Throws:
SQLException - if a database access error occurs

unwrap

public <T> T unwrap(Class<T> iface)
         throws SQLException
Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy. If the receiver implements the interface then the result is the receiver or a proxy for the receiver. If the receiver is a wrapper and the wrapped object implements the interface then the result is the wrapped object or a proxy for the wrapped object. Otherwise return the the result of calling unwrap recursively on the wrapped object or a proxy for that result. If the receiver is not a wrapper and does not implement the interface, then an SQLException is thrown.

Specified by:
unwrap in interface Wrapper
Parameters:
iface - A Class defining an interface that the result must implement.
Returns:
an object that implements the interface. May be a proxy for the actual implementing object.
Throws:
SQLException - If no object found that implements the interface
Since:
JDK 1.6, HSQLDB 2.0

isWrapperFor

public boolean isWrapperFor(Class<?> iface)
                     throws SQLException
Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does. Returns false otherwise. If this implements the interface then return true, else if this is a wrapper then return the result of recursively calling isWrapperFor on the wrapped object. If this does not implement the interface and is not a wrapper, return false. This method should be implemented as a low-cost operation compared to unwrap so that callers can use this method to avoid expensive unwrap calls that may fail. If this method returns true then calling unwrap with the same argument should succeed.

Specified by:
isWrapperFor in interface Wrapper
Parameters:
iface - a Class defining an interface.
Returns:
true if this implements the interface or directly or indirectly wraps an object that does.
Throws:
SQLException - if an error occurs while determining whether this is a wrapper for an object with the given interface.
Since:
JDK 1.6, HSQLDB 2.0

getDatabase

public String getDatabase()
Retrieves the jdbc database connection url attribute.

Returns:
the jdbc database connection url attribute

getLoginTimeout

public int getLoginTimeout()
                    throws SQLException
Gets the maximum time in seconds that this data source can wait while attempting to connect to a database. A value of zero means that the timeout is the default system timeout if there is one; otherwise, it means that there is no timeout. When a DataSource object is created, the login timeout is initially zero.

Specified by:
getLoginTimeout in interface CommonDataSource
Returns:
the data source login time limit
Throws:
SQLException - if a database access error occurs.
See Also:
setLoginTimeout(int), setLoginTimeout(int)

getLogWriter

public PrintWriter getLogWriter()
                         throws SQLException

Retrieves the log writer for this DataSource object.

The log writer is a character output stream to which all logging and tracing messages for this data source will be printed. This includes messages printed by the methods of this object, messages printed by methods of other objects manufactured by this object, and so on. Messages printed to a data source specific log writer are not printed to the log writer associated with the java.sql.Drivermanager class. When a DataSource object is created, the log writer is initially null; in other words, the default is for logging to be disabled.

Specified by:
getLogWriter in interface CommonDataSource
Returns:
the log writer for this data source or null if logging is disabled
Throws:
SQLException - if a database access error occurs
See Also:
setLogWriter(java.io.PrintWriter)

getReference

public Reference getReference()
                       throws NamingException
Specified by:
getReference in interface Referenceable
Throws:
NamingException

getUser

public String getUser()
Retrieves the user ID for the connection.

Returns:
the user ID for the connection

setDatabase

public void setDatabase(String database)
Assigns the value of this object's jdbc database connection url attribute.

Parameters:
database - the new value of this object's jdbc database connection url attribute

setLoginTimeout

public void setLoginTimeout(int seconds)
                     throws SQLException

Sets the maximum time in seconds that this data source will wait while attempting to connect to a database. A value of zero specifies that the timeout is the default system timeout if there is one; otherwise, it specifies that there is no timeout. When a DataSource object is created, the login timeout is initially zero.

Specified by:
setLoginTimeout in interface CommonDataSource
Parameters:
seconds - the data source login time limit
Throws:
SQLException - if a database access error occurs.
See Also:
getLoginTimeout()

setLogWriter

public void setLogWriter(PrintWriter logWriter)
                  throws SQLException

Sets the log writer for this DataSource object to the given java.io.PrintWriter object.

The log writer is a character output stream to which all logging and tracing messages for this data source will be printed. This includes messages printed by the methods of this object, messages printed by methods of other objects manufactured by this object, and so on. Messages printed to a data source- specific log writer are not printed to the log writer associated with the java.sql.DriverManager class. When a DataSource object is created the log writer is initially null; in other words, the default is for logging to be disabled.

Specified by:
setLogWriter in interface CommonDataSource
Parameters:
logWriter - the new log writer; to disable logging, set to null
Throws:
SQLException - if a database access error occurs
See Also:
getLogWriter()

setPassword

public void setPassword(String password)
Sets the password to use for connecting to the database

Parameters:
password - the password

setUser

public void setUser(String user)
Sets the userid

Parameters:
user - the user id


Copyright © 2001 - 2009 HSQL Development Group.