Package org.apache.xalan.lib.sql
Interface ConnectionPool
- All Known Implementing Classes:
DefaultConnectionPool,JNDIConnectionPool
public interface ConnectionPool
An interface used to build wrapper classes around existing
Connection Pool libraries.
Title: ConnectionPool
- Version:
- 1.0
- Author:
- John Gentilin
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Method Summary
Modifier and TypeMethodDescriptionvoidStart downsizeing the pool, this usally happens right after the pool has been marked as Inactive and we are removing connections that are not currently inuse.Retrive a database connection from the poolbooleanProvide an indicator to the PoolManager when the Pool can be removed from the Pool Table.booleanDetermine if a Connection Pool has been disabled.voidReturn a connection to the pool, the connection may be closed if the pool is inactive or has exceeded the max number of free connectionsvoidProvide a mechinism to return a connection to the pool on Error.voidThe Driver and URL are the only required parmeters.voidsetMinConnections(int n) Set tne minimum number of connections that are to be maintained in the pool.voidThe rest of the protocol parameters can eiter be passed in as just Username and Password or as a property collection.voidsetPoolEnabled(boolean flag) The Pool can be Enabled and Disabled.voidUsed to pass in extra configuration options during the database connect phase.voidvoidbooleanTest to see if the connection info is valid to make a real connection to the database.
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Method Details
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isEnabled
boolean isEnabled()Determine if a Connection Pool has been disabled. If a Connection pool is disabled, then it will only manage connections that are in use. -
setDriver
The Driver and URL are the only required parmeters.- Parameters:
d-
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setURL
- Parameters:
url-
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freeUnused
void freeUnused()Start downsizeing the pool, this usally happens right after the pool has been marked as Inactive and we are removing connections that are not currently inuse. -
hasActiveConnections
boolean hasActiveConnections()Provide an indicator to the PoolManager when the Pool can be removed from the Pool Table. -
setPassword
The rest of the protocol parameters can eiter be passed in as just Username and Password or as a property collection. If the property collection is used, then the sperate username and password may be ignored, it is up to the wrapper implementation to handle the situation. If the connection information changes while after the pool has been established, the wrapper implementation should ignore the change and throw an error.- Parameters:
p-
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setUser
- Parameters:
u-
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setMinConnections
void setMinConnections(int n) Set tne minimum number of connections that are to be maintained in the pool.- Parameters:
n-
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testConnection
boolean testConnection()Test to see if the connection info is valid to make a real connection to the database. This method may cause the pool to be crated and filled with min connections. -
getConnection
Retrive a database connection from the pool- Throws:
SQLException
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releaseConnection
Return a connection to the pool, the connection may be closed if the pool is inactive or has exceeded the max number of free connections- Parameters:
con-- Throws:
SQLException
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releaseConnectionOnError
Provide a mechinism to return a connection to the pool on Error. A good default behaviour is to close this connection and build a new one to replace it. Some JDBC impl's won't allow you to reuse a connection after an error occurs.- Parameters:
con-- Throws:
SQLException
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setPoolEnabled
void setPoolEnabled(boolean flag) The Pool can be Enabled and Disabled. Disabling the pool closes all the outstanding Unused connections and any new connections will be closed upon release.- Parameters:
flag- Control the Connection Pool. If it is enabled then Connections will actuall be held around. If disabled then all unused connections will be instantly closed and as connections are released they are closed and removed from the pool.
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setProtocol
Used to pass in extra configuration options during the database connect phase.
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