Package com.ziclix.python.sql

Class DataHandler

java.lang.Object
com.ziclix.python.sql.DataHandler
Direct Known Subclasses:
FilterDataHandler, Jython22DataHandler
public class DataHandler extends 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

  • Constructor Details

    • DataHandler

      public DataHandler()
      Handle most generic Java data types.

  • Method Details

    • getMetaDataName

      public 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.

    • getProcedure

      public Procedure getProcedure(PyCursor cursor, PyObject name) throws SQLException
      A factory method for determing the correct procedure class to use per the cursor type.
      Parameters:
      cursor - an open cursor
      name - the name of the procedure to invoke
      Returns:
      an instance of a Procedure
      Throws:
      SQLException

    • getRowId

      public PyObject getRowId(Statement stmt) throws 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:
      SQLException - thrown if an exception occurs

    • preExecute

      public void preExecute(Statement stmt) throws SQLException
      A callback prior to each execution of the statement. If the statement is a PreparedStatement, all the parameters will have been set.
      Throws:
      SQLException

    • postExecute

      public void postExecute(Statement stmt) throws SQLException
      A callback after successfully executing the statement.
      Throws:
      SQLException

    • setJDBCObject

      public void setJDBCObject(PreparedStatement stmt, int index, PyObject object) throws 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 PreparedStatement
      index - the index for which this object is bound
      object - the PyObject in question
      Throws:
      SQLException

    • setJDBCObject

      public void setJDBCObject(PreparedStatement stmt, int index, PyObject object, int type) throws 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 PreparedStatement
      index - the index for which this object is bound
      object - the PyObject in question
      type - the java.sql.Types for which this PyObject should be bound
      Throws:
      SQLException

    • getPyObject

      public PyObject getPyObject(ResultSet set, int col, int type) throws 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 row
      col - the column number (adjusted properly for JDBC)
      type - the column type
      Throws:
      SQLException - if the type is unmappable

    • getPyObject

      public PyObject getPyObject(CallableStatement stmt, int col, int type) throws SQLException
      Given a CallableStatement, column and type, return the appropriate Jython object.
      Parameters:
      stmt - the CallableStatement
      col - the column number (adjusted properly for JDBC)
      type - the column type
      Throws:
      SQLException - if the type is unmappable

    • registerOut

      public void registerOut(CallableStatement statement, int index, int colType, int dataType, String dataTypeName) throws 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 number
      colType - the column as from DatabaseMetaData (eg, procedureColumnOut)
      dataType - the JDBC datatype from Types
      dataTypeName - the JDBC datatype name
      Throws:
      SQLException

    • checkNull

      public static final boolean checkNull(PreparedStatement stmt, int index, PyObject object, int type) throws 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:
      SQLException

    • read

      public static final byte[] read(InputStream stream)
      Consume the InputStream into an byte array and close the InputStream.
      Returns:
      the contents of the InputStream a byte[]

    • read

      public static String read(Reader reader)
      Consume the Reader into a String and close the Reader.
      Returns:
      the contents of the Reader as a String

    • 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

    • __chain__

      public PyObject __chain__()
      Returns a list of datahandlers chained together through the use of delegation.
      Returns:
      a list of datahandlers

    • toString

      public String toString()
      Returns the classname of this datahandler.
      Overrides:
      toString in class Object