javax.sql
Interface DataSource
- public interface DataSource
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:
- Basic implementation -- produces a standard Connection object
- Connection pooling implementation -- produces a Connection object that will automatically participate in connection pooling. This implementation works with a middle-tier connection pooling manager.
- 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:
- 1.4
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.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.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 out)
Sets the log writer for this DataSource object to the given java.io.PrintWriter object.
Method Detail
getConnection
public Connection getConnection() throws SQLException
Attempts to establish a connection with the data source that this DataSource object represents.
- 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.
- 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
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.
- 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)
setLogWriter
public void setLogWriter(PrintWriter out) 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.
- Parameters:
- out - the new log writer; to disable logging, set to null
- Throws:
- SQLException - if a database access error occurs
- See Also:
- getLogWriter()
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.
- Parameters:
- seconds - the data source login time limit
- Throws:
- SQLException - if a database access error occurs.
- See Also:
- getLoginTimeout()
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.
- Returns:
- the data source login time limit
- Throws:
- SQLException - if a database access error occurs.
- See Also:
- setLoginTimeout(int)