Package gov.usgs.earthquake.util

Class JDBCConnection

java.lang.Object

gov.usgs.util.DefaultConfigurable

gov.usgs.earthquake.util.JDBCConnection

All Implemented Interfaces:

Configurable, java.lang.AutoCloseable

Direct Known Subclasses:

JDBCNotificationIndex, JDBCProductIndex, JsonNotificationIndex, JsonProductStorage, TrackingIndex

public class JDBCConnection
extends DefaultConfigurable
implements java.lang.AutoCloseable

Utility class for JDBC Connection. Sub-classes must implement the connect method, and extend startup and shutdown methods. The verifyConnection() method tests whether the connection is active, and will shutdown() and startup() to reinitialize if it is not active.

Constructor Summary

Constructors

Constructor	Description
JDBCConnection()	Create a new JDBCConnection object.
JDBCConnection(java.lang.String driver, java.lang.String url)	Create a new JDBCConnection object with specific driver and URL

Method Summary

Modifier and Type	Method	Description
void	beginTransaction()	Open a transaction on the database connection
void	close()	Implement autocloseable.
void	commitTransaction()	Finalize the transaction by committing all the changes and closing the transaction.
void	configure(Config config)	Implement Configurable
protected java.sql.Connection	connect()	Connect to the database.
java.sql.Connection	getConnection()
java.lang.String	getDriver()
java.lang.String	getUrl()
void	rollbackTransaction()	Undo all of the changes made during the current transaction
void	setDriver(java.lang.String driver)
void	setUrl(java.lang.String url)
void	shutdown()	Shutdown the database connection.
void	startup()	Initialize the database connection.
java.sql.Connection	verifyConnection()	Check whether database connection is closed, and reconnect if needed.

Methods inherited from class gov.usgs.util.DefaultConfigurable

getName, setName

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JDBCConnection

public JDBCConnection()

Create a new JDBCConnection object.

JDBCConnection

public JDBCConnection(java.lang.String driver,
                      java.lang.String url)

Create a new JDBCConnection object with specific driver and URL

Parameters:

driver - String of driver

url - String of URL

Method Detail

close

public void close()
           throws java.lang.Exception

Implement autocloseable. Calls shutdown().

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.lang.Exception - Exception

configure

public void configure(Config config)
               throws java.lang.Exception

Implement Configurable

Specified by:

configure in interface Configurable

Overrides:

configure in class DefaultConfigurable

Parameters:

config - Config to set driver and URL in

Throws:

java.lang.Exception - Exception

connect

protected java.sql.Connection connect()
                               throws java.lang.Exception

Connect to the database. Sub-classes determine how connection is made.

Returns:

the connection.

Throws:

java.lang.Exception - if unable to connect.

startup

public void startup()
             throws java.lang.Exception

Initialize the database connection. Sub-classes should call super.startup(), before preparing any statements.

Specified by:

startup in interface Configurable

Overrides:

startup in class DefaultConfigurable

Throws:

java.lang.Exception - if error occurs

shutdown

public void shutdown()
              throws java.lang.Exception

Shutdown the database connection. Sub-classes should close any prepared statements (catching any exceptions), and then call super.shutdown() to close the database connection.

Specified by:

shutdown in interface Configurable

Overrides:

shutdown in class DefaultConfigurable

Throws:

java.lang.Exception - if error occurs

beginTransaction

public void beginTransaction()
                      throws java.lang.Exception

Open a transaction on the database connection

Throws:

java.lang.Exception - if error occurs

commitTransaction

public void commitTransaction()
                       throws java.lang.Exception

Finalize the transaction by committing all the changes and closing the transaction.

Throws:

java.lang.Exception - if error occurs

rollbackTransaction

public void rollbackTransaction()
                         throws java.lang.Exception

Undo all of the changes made during the current transaction

Throws:

java.lang.Exception - if error occurs

getConnection

public java.sql.Connection getConnection()

Returns:

current connection object, or null if not connected.

verifyConnection

public java.sql.Connection verifyConnection()
                                     throws java.lang.Exception

Check whether database connection is closed, and reconnect if needed. Executes the query "select 1" using the current database connection. If this doesn't succeed, reinitializes the database connection by calling shutdown() then startup().

Returns:

Valid connection object.

Throws:

java.lang.Exception - if unable to (re)connect.

getDriver

public java.lang.String getDriver()

Returns:

driver

setDriver

public void setDriver(java.lang.String driver)

Parameters:

driver - Driver to set

getUrl

public java.lang.String getUrl()

Returns:

URL

setUrl

public void setUrl(java.lang.String url)

Parameters:

url - URL to set