| <?xml version="1.0"?> |
| |
| <document> |
| <properties> |
| <title>Turbine Services - DB Service</title> |
| <author email="jvanzyl@apache.org">Jason van Zyl</author> |
| </properties> |
| |
| <body> |
| |
| <section name="DB Service"> |
| |
| <p> |
| <b>This service is deprecated. It is just a facade for Torque.</b> |
| <br/> |
| 'DB Service' includes two services: |
| <ul> |
| <li>PoolBrokerService - provides database connection pooling</li> |
| <li>MapBrokerService - manages DatabaseMap objects</li> |
| </ul> |
| |
| </p> |
| |
| </section> |
| |
| <section name="Configuration"> |
| |
| <source><![CDATA[ |
| # ------------------------------------------------------------------- |
| # |
| # S E R V I C E S |
| # |
| # ------------------------------------------------------------------- |
| # Classes for Turbine Services should be defined here. |
| # Format: services.[name].classname=[implementing class] |
| # |
| # To specify properties of a service use the following syntax: |
| # service.[name].[property]=[value] |
| |
| services.PoolBrokerService.classname=org.apache.turbine.services.db.TurbinePoolBrokerService |
| services.MapBrokerService.classname=org.apache.turbine.services.db.TurbineMapBrokerService |
| . |
| . |
| . |
| # ------------------------------------------------------------------- |
| # |
| # D A T A B A S E S E T T I N G S |
| # |
| # ------------------------------------------------------------------- |
| # These are your database settings. Look in the |
| # org.apache.turbine.util.db.pool.* packages for more information. |
| # The default driver for Turbine is for MySQL. |
| # |
| # The parameters to connect to the default database. You MUST |
| # configure these properly. |
| # ------------------------------------------------------------------- |
| |
| database.default.driver=org.gjt.mm.mysql.Driver |
| database.default.url=jdbc:mysql://localhost:3306/Turbine |
| database.default.username=username |
| database.default.password=password |
| |
| # The number of database connections to cache per ConnectionPool |
| # instance (specified per database). |
| |
| database.default.maxConnections=3 |
| |
| # The amount of time (in milliseconds) that database connections will be |
| # cached (specified per database). |
| # |
| # Default: one hour = 60 * 60 * 1000 |
| |
| database.default.expiryTime=3600000 |
| |
| # The amount of time (in milliseconds) a connection request will have to wait |
| # before a time out occurs and an error is thrown. |
| # |
| # Default: ten seconds = 10 * 1000 |
| |
| database.connectionWaitTimeout=10000 |
| |
| # The interval (in milliseconds) between which the PoolBrokerService logs |
| # the status of it's ConnectionPools. |
| # |
| # Default: No logging = 0 = 0 * 1000 |
| |
| database.logInterval=0 |
| |
| # These are the supported JDBC drivers and their associated Turbine |
| # adaptor. These properties are used by the DBFactory. You can add |
| # all the drivers you want here. |
| |
| database.adaptor=DBMM |
| database.adaptor.DBMM=org.gjt.mm.mysql.Driver |
| |
| # Determines if the quantity column of the IDBroker's id_table should |
| # be increased automatically if requests for ids reaches a high |
| # volume. |
| |
| database.idbroker.cleverquantity=true |
| |
| # ------------------------------------------------------------------- |
| # |
| # P E E R S |
| # |
| # ------------------------------------------------------------------- |
| # Supplies Turbine with information about the database schema, which |
| # can simplify any required Peer classes. |
| # |
| # Default: org.apache.turbine.util.db.map.TurbineMapBuilder |
| # ------------------------------------------------------------------- |
| |
| database.maps.builder=org.apache.turbine.util.db.map.TurbineMapBuilder |
| |
| ]]></source> |
| |
| </section> |
| |
| <section name="Usage"> |
| |
| <subsection name="PoolBrokerService"> |
| |
| <p> |
| To obtain a connection from the default pool, all you need to do is |
| write code like this: |
| </p> |
| |
| <source><![CDATA[ |
| DBConnection dbConn = null; |
| try |
| { |
| dbConn = TurbineDB.getConnection(); |
| // Do something with the connection here... |
| } |
| catch (Exception e) |
| { |
| // Either from obtaining the connection or from your application code. |
| } |
| finally |
| { |
| try |
| { |
| TurbineDB.releaseConnection(dbConn); |
| } |
| catch (Exception e) |
| { |
| // Error releasing database connection back to pool. |
| } |
| } |
| ]]></source> |
| |
| <p> |
| To obtain a connection from another pool, simply pass the name of the other |
| pool to the TurbineDB: |
| </p> |
| |
| <source><![CDATA[ |
| DBConnection db = TurbineDB.getConnection("mypoolname"); |
| ]]></source> |
| |
| <p> |
| You should always make sure to enclose your code within |
| the try/finally block so that you make sure to always release the connection |
| back to the pool. If you experience a situation where it seems like your |
| code locks up after a while and you do not get results back from the browser, |
| then chances are that you have forgotten to release a connection back to |
| the pool for some reason. An enhancement to the pooling code would be to |
| add a background cleanup thread that cleans up connections that have not |
| been released back to the pool after a determined amount of time. This |
| does not fix the problem of bad code, but would help in situations where |
| bad code does manage to find its way into the system. |
| </p> |
| </subsection> |
| </section> |
| |
| </body> |
| </document> |
