DataSourceProcess¶
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public abstract class
DataSourceProcess
¶ DataSourceProcess represents a data source transaction process. Subclasses are required to implement the doTransaction() method for the transaction process.
This process will only manage, for example commit or rollback, the transaction encapsulated if its DataSourceDAO is not under a transaction and it is not explicitly instructed, in construction, to use a specified transaction.
Author: Hugo Y. K. Lam
Constructors¶
DataSourceProcess¶
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public
DataSourceProcess
(DataSourceDAO dao)¶ Creates a new instance of DataSourceProcess.
Parameters: - dao – the DAO to which this process correspond.
DataSourceProcess¶
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public
DataSourceProcess
(DataSourceDAO dao, DataSourceTransaction transaction)¶ Creates a new instance of DataSourceProcess.
Parameters: - dao – the DAO to which this process correspond.
- transaction – the transaction in which this process should execute.
Methods¶
doTransaction¶
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protected abstract void
doTransaction
(DataSourceTransaction tx)¶ Executes the transaction process.
Parameters: - tx – the DataSourceTransaction object in which this process executes.
Throws: - DAOException – if any error occurred in the execution.
getDAO¶
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protected DataSourceDAO
getDAO
()¶ Gets the DAO to which this process correspond.
Returns: the DAO to which this process correspond.
getParameterCount¶
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protected int
getParameterCount
(PreparedStatement pStmt, String sql)¶ Counts the number of parameters required by the prepared statement. If a parameter meta data is not available, it counts the occurrences of ‘?’ in the given SQL statement.
Parameters: - pStmt – the prepared statement.
- sql – the SQL statement.
Returns: the numbder of parameters.
getResult¶
isCommitted¶
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public boolean
isCommitted
()¶ Checks if this process has committed the transaction.
Returns: true if this process has committed the transaction.
isRolledBack¶
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public boolean
isRolledBack
()¶ Checks if this process has rolled back the transaction.
Returns: true if this process has rolled back the transaction.
isStarted¶
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public boolean
isStarted
()¶ Checks if this process has already been started.
Returns: true if the this process has already been started.
setParameter¶
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protected void
setParameter
(PreparedStatement pStmt, int pos, Object param)¶ Sets a parameter to the prepared statement.
Parameters: - pStmt – the prepared statement.
- pos – the position of the parameter.
- param – the parameter.
Throws: - SQLException – if unable to set the parameter.
setResult¶
start¶
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public synchronized void
start
()¶ Starts executing this process. A process can only be started if it has not yet been started.
Throws: - DAOException – if there is any error in the execution or the process has already been started.
toString¶
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public String
toString
()¶ Returns a string representation of this process.
Returns: a string representation of this process. See also:
java.lang.Object.toString()