Package com.ziclix.python.sql
Class DataHandler
- java.lang.Object
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- com.ziclix.python.sql.DataHandler
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- Direct Known Subclasses:
FilterDataHandler
,Jython22DataHandler
public class DataHandler extends java.lang.Object
The DataHandler is responsible mapping the JDBC data type to a Jython object. Depending on the version of the JDBC implementation and the particulars of the driver, the type mapping can be significantly different. This interface can also be used to change the behaviour of the default mappings provided by the cursor. This might be useful in handling more complicated data types such as BLOBs, CLOBs and Arrays.- Author:
- brian zimmer
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Constructor Summary
Constructors Constructor Description DataHandler()
Handle most generic Java data types.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description PyObject
__chain__()
Returns a list of datahandlers chained together through the use of delegation.static boolean
checkNull(java.sql.PreparedStatement stmt, int index, PyObject object, int type)
Handles checking if the object is null or None and setting it on the statement.java.lang.String
getMetaDataName(PyObject name)
Some database vendors are case sensitive on calls to DatabaseMetaData, most notably Oracle.Procedure
getProcedure(PyCursor cursor, PyObject name)
A factory method for determing the correct procedure class to use per the cursor type.PyObject
getPyObject(java.sql.CallableStatement stmt, int col, int type)
Given a CallableStatement, column and type, return the appropriate Jython object.PyObject
getPyObject(java.sql.ResultSet set, int col, int type)
Given a ResultSet, column and type, return the appropriate Jython object.PyObject
getRowId(java.sql.Statement stmt)
Returns the row id of the last executed statement.static DataHandler
getSystemDataHandler()
Build the DataHandler chain depending on the VM.void
postExecute(java.sql.Statement stmt)
A callback after successfully executing the statement.void
preExecute(java.sql.Statement stmt)
A callback prior to each execution of the statement.static byte[]
read(java.io.InputStream stream)
Consume the InputStream into an byte array and close the InputStream.static java.lang.String
read(java.io.Reader reader)
Consume the Reader into a String and close the Reader.void
registerOut(java.sql.CallableStatement statement, int index, int colType, int dataType, java.lang.String dataTypeName)
Called when a stored procedure or function is executed and OUT parameters need to be registered with the statement.void
setJDBCObject(java.sql.PreparedStatement stmt, int index, PyObject object)
Any .execute() which uses prepared statements will receive a callback for deciding how to map the PyObject to the appropriate JDBC type.void
setJDBCObject(java.sql.PreparedStatement stmt, int index, PyObject object, int type)
Any .execute() which uses prepared statements will receive a callback for deciding how to map the PyObject to the appropriate JDBC type.java.lang.String
toString()
Returns the classname of this datahandler.
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Method Detail
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getMetaDataName
public java.lang.String getMetaDataName(PyObject name)
Some database vendors are case sensitive on calls to DatabaseMetaData, most notably Oracle. This callback allows a DataHandler to affect the name.
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getProcedure
public Procedure getProcedure(PyCursor cursor, PyObject name) throws java.sql.SQLException
A factory method for determing the correct procedure class to use per the cursor type.- Parameters:
cursor
- an open cursorname
- the name of the procedure to invoke- Returns:
- an instance of a Procedure
- Throws:
java.sql.SQLException
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getRowId
public PyObject getRowId(java.sql.Statement stmt) throws java.sql.SQLException
Returns the row id of the last executed statement.- Parameters:
stmt
- the current statement- Returns:
- the row id of the last executed statement or None
- Throws:
java.sql.SQLException
- thrown if an exception occurs
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preExecute
public void preExecute(java.sql.Statement stmt) throws java.sql.SQLException
A callback prior to each execution of the statement. If the statement is a PreparedStatement, all the parameters will have been set.- Throws:
java.sql.SQLException
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postExecute
public void postExecute(java.sql.Statement stmt) throws java.sql.SQLException
A callback after successfully executing the statement.- Throws:
java.sql.SQLException
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setJDBCObject
public void setJDBCObject(java.sql.PreparedStatement stmt, int index, PyObject object) throws java.sql.SQLException
Any .execute() which uses prepared statements will receive a callback for deciding how to map the PyObject to the appropriate JDBC type.- Parameters:
stmt
- the current PreparedStatementindex
- the index for which this object is boundobject
- the PyObject in question- Throws:
java.sql.SQLException
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setJDBCObject
public void setJDBCObject(java.sql.PreparedStatement stmt, int index, PyObject object, int type) throws java.sql.SQLException
Any .execute() which uses prepared statements will receive a callback for deciding how to map the PyObject to the appropriate JDBC type. The type is the JDBC type as obtained from java.sql.Types.- Parameters:
stmt
- the current PreparedStatementindex
- the index for which this object is boundobject
- the PyObject in questiontype
- the java.sql.Types for which this PyObject should be bound- Throws:
java.sql.SQLException
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getPyObject
public PyObject getPyObject(java.sql.ResultSet set, int col, int type) throws java.sql.SQLException
Given a ResultSet, column and type, return the appropriate Jython object.Note: DO NOT iterate the ResultSet.
- Parameters:
set
- the current ResultSet set to the current rowcol
- the column number (adjusted properly for JDBC)type
- the column type- Throws:
java.sql.SQLException
- if the type is unmappable
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getPyObject
public PyObject getPyObject(java.sql.CallableStatement stmt, int col, int type) throws java.sql.SQLException
Given a CallableStatement, column and type, return the appropriate Jython object.- Parameters:
stmt
- the CallableStatementcol
- the column number (adjusted properly for JDBC)type
- the column type- Throws:
java.sql.SQLException
- if the type is unmappable
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registerOut
public void registerOut(java.sql.CallableStatement statement, int index, int colType, int dataType, java.lang.String dataTypeName) throws java.sql.SQLException
Called when a stored procedure or function is executed and OUT parameters need to be registered with the statement.- Parameters:
statement
-index
- the JDBC offset column numbercolType
- the column as from DatabaseMetaData (eg, procedureColumnOut)dataType
- the JDBC datatype from TypesdataTypeName
- the JDBC datatype name- Throws:
java.sql.SQLException
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checkNull
public static final boolean checkNull(java.sql.PreparedStatement stmt, int index, PyObject object, int type) throws java.sql.SQLException
Handles checking if the object is null or None and setting it on the statement.- Returns:
- true if the object is null and was set on the statement, false otherwise
- Throws:
java.sql.SQLException
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read
public static final byte[] read(java.io.InputStream stream)
Consume the InputStream into an byte array and close the InputStream.- Returns:
- the contents of the InputStream a byte[]
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read
public static java.lang.String read(java.io.Reader reader)
Consume the Reader into a String and close the Reader.- Returns:
- the contents of the Reader as a String
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getSystemDataHandler
public static final DataHandler getSystemDataHandler()
Build the DataHandler chain depending on the VM. This guarentees a DataHandler but might additionally chain a JDBC2.0 or JDBC3.0 implementation.- Returns:
- a DataHandler configured for the VM version
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__chain__
public PyObject __chain__()
Returns a list of datahandlers chained together through the use of delegation.- Returns:
- a list of datahandlers
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toString
public java.lang.String toString()
Returns the classname of this datahandler.- Overrides:
toString
in classjava.lang.Object
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