Class DataHandler

  • 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
    • Constructor Summary

      Constructors 
      Constructor Description
      DataHandler()
      Handle most generic Java data types.
    • 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.
      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Constructor Detail

      • DataHandler

        public DataHandler()
        Handle most generic Java data types.
    • Method Detail

      • 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.
      • 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 cursor
        name - the name of the procedure to invoke
        Returns:
        an instance of a Procedure
        Throws:
        java.sql.SQLException
      • 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
      • 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
      • postExecute

        public void postExecute​(java.sql.Statement stmt)
                         throws java.sql.SQLException
        A callback after successfully executing the statement.
        Throws:
        java.sql.SQLException
      • 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 PreparedStatement
        index - the index for which this object is bound
        object - the PyObject in question
        Throws:
        java.sql.SQLException
      • 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 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:
        java.sql.SQLException
      • 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 row
        col - the column number (adjusted properly for JDBC)
        type - the column type
        Throws:
        java.sql.SQLException - if the type is unmappable
      • 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 CallableStatement
        col - the column number (adjusted properly for JDBC)
        type - the column type
        Throws:
        java.sql.SQLException - if the type is unmappable
      • 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 number
        colType - the column as from DatabaseMetaData (eg, procedureColumnOut)
        dataType - the JDBC datatype from Types
        dataTypeName - the JDBC datatype name
        Throws:
        java.sql.SQLException
      • 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
      • 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[]
      • 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
      • 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 java.lang.String toString()
        Returns the classname of this datahandler.
        Overrides:
        toString in class java.lang.Object