de.mathema.pride
Class ExtendedAttributeDescriptor

java.lang.Object
  de.mathema.pride.ExtendedAttributeDescriptor

All Implemented Interfaces:

RecordDescriptor.ExtractionMode, SQLExpression.Operator

public class ExtendedAttributeDescriptor
extends java.lang.Object

Author:

Jan Lessner

Field Summary

protected java.lang.reflect.Method	conversionMethod
protected int	databaseColumnType
protected java.lang.String	databaseFieldName
protected java.lang.reflect.Method	databaseGetByIndexMethod Method to fetch data from a database result set by index
protected java.lang.reflect.Method	databaseGetByNameMethod Method to fetch data from a database result set by name
protected java.lang.reflect.Method	databaseSetMethod Method to store data in a database prepared statement
protected java.lang.Class<java.lang.Enum>	enumType True if the attribute represented by this descriptor is an enumeration type
protected int	extractionMode Specifies the ResultSet data extraction mode.
protected java.lang.reflect.Method	getMethod
protected boolean	isPrimitive True if the attribute represented by this descriptor is of a primitive type
static java.lang.String	REVISION_ID
protected java.lang.reflect.Method	setMethod

Fields inherited from interface de.mathema.pride.SQLExpression.Operator

BETWEEN, EQUAL, GREATER, GREATEREQUAL, IN, LESS, LESSEQUAL, LIKE, NOTIN, UNEQUAL

Fields inherited from interface de.mathema.pride.RecordDescriptor.ExtractionMode

AUTO, INDEX, NAME

Constructor Summary

ExtendedAttributeDescriptor(java.lang.Class objectType, java.lang.String[] attrInfo, int extractionMode)

Method Summary

void	applyResult(java.lang.Object obj, java.lang.String stringValue)
int	getColumnType(java.sql.Connection con, java.lang.String table) Retrieve the column's SQL type, required for setting NULL values in prepared statements.
protected static java.lang.reflect.Method	getConversionMethod(java.lang.Class destinationType)
java.lang.String	getCreationValue(java.lang.Object obj, Database db) Returns a string representation of the passed object's value for this descriptor's attribute.
java.lang.String	getFieldName() Returns the database field name
int	getParameter(java.lang.Object obj, PreparedOperation pop, java.lang.String table, int position) Writes an attribute of the passed value object to a PreparedOperation
java.lang.String	getUpdateValue(java.lang.Object obj, Database db) Returns an update expression of the form " = " by extracting the pased object's value for this descriptor's attribute.
java.lang.Object	getValue(java.lang.Object obj) Returns the object's value for this attribute
java.lang.String	getWhereValue(java.lang.Object obj, Database db, boolean byLike) Returns a constraint expression of the form " = " if the objects's value for this descriptor's attribute defers from null, " IS NULL" otherwise
protected void	record2object(java.lang.Object obj, java.sql.ResultSet results, int position) Fetch a value from a database result set and copy it into an object according to this attribute descriptor
protected java.lang.Object	record2object(java.sql.ResultSet results, int position) Fetch a value from a database result set according to this descriptor's extraction mode.
protected int	selectDataType(java.sql.Connection con, java.lang.String table, java.lang.String column)
protected static void	setConversionMethods()
protected java.lang.Object	wrapArrayTypedValue(java.sql.Connection connection, java.lang.Object attrValue)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

conversionMethod

protected java.lang.reflect.Method conversionMethod

REVISION_ID

public static final java.lang.String REVISION_ID

See Also:

Constant Field Values

databaseFieldName

protected java.lang.String databaseFieldName

databaseColumnType

protected int databaseColumnType

databaseGetByNameMethod

protected java.lang.reflect.Method databaseGetByNameMethod

Method to fetch data from a database result set by name

databaseGetByIndexMethod

protected java.lang.reflect.Method databaseGetByIndexMethod

Method to fetch data from a database result set by index

databaseSetMethod

protected java.lang.reflect.Method databaseSetMethod

Method to store data in a database prepared statement

getMethod

protected java.lang.reflect.Method getMethod

setMethod

protected java.lang.reflect.Method setMethod

extractionMode

protected int extractionMode

Specifies the ResultSet data extraction mode. See class RecordDescriptor for details.

isPrimitive

protected boolean isPrimitive

True if the attribute represented by this descriptor is of a primitive type

enumType

protected java.lang.Class<java.lang.Enum> enumType

True if the attribute represented by this descriptor is an enumeration type

Constructor Detail

ExtendedAttributeDescriptor

public ExtendedAttributeDescriptor(java.lang.Class objectType,
                                   java.lang.String[] attrInfo,
                                   int extractionMode)
                            throws IllegalDescriptorException

Throws:

IllegalDescriptorException

Method Detail

setConversionMethods

protected static void setConversionMethods()
                                    throws java.lang.NoSuchMethodException

Throws:

java.lang.NoSuchMethodException

getConversionMethod

protected static java.lang.reflect.Method getConversionMethod(java.lang.Class destinationType)
                                                       throws java.lang.NoSuchMethodException

Throws:

java.lang.NoSuchMethodException

applyResult

public void applyResult(java.lang.Object obj,
                        java.lang.String stringValue)
                 throws java.lang.IllegalAccessException,
                        java.lang.reflect.InvocationTargetException

Throws:

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

getFieldName

public java.lang.String getFieldName()

Returns the database field name

getColumnType

public int getColumnType(java.sql.Connection con,
                         java.lang.String table)
                  throws java.sql.SQLException

Retrieve the column's SQL type, required for setting NULL values in prepared statements. The retrieval is performed lazy as it may take some time and is not always required.

Parameters:

con - the database connection to fetch meta data from

table - the database table to fetch the column type from. The function assumes that the type is equal in all tables making use of the same attribute descriptor (e.g. all tables of a descriptor derivation hierarchy).

Throws:

java.sql.SQLException - if meta data retrieval failed

selectDataType

protected int selectDataType(java.sql.Connection con,
                             java.lang.String table,
                             java.lang.String column)
                      throws java.sql.SQLException

Throws:

java.sql.SQLException

getValue

public java.lang.Object getValue(java.lang.Object obj)
                          throws java.lang.IllegalAccessException,
                                 java.lang.reflect.InvocationTargetException

Returns the object's value for this attribute

Throws:

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

getUpdateValue

public java.lang.String getUpdateValue(java.lang.Object obj,
                                       Database db)
                                throws java.lang.IllegalAccessException,
                                       java.lang.reflect.InvocationTargetException

Returns an update expression of the form " = " by extracting the pased object's value for this descriptor's attribute.

Throws:

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

getWhereValue

public java.lang.String getWhereValue(java.lang.Object obj,
                                      Database db,
                                      boolean byLike)
                               throws java.lang.IllegalAccessException,
                                      java.lang.reflect.InvocationTargetException

Returns a constraint expression of the form " = " if the objects's value for this descriptor's attribute defers from null, " IS NULL" otherwise

Throws:

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

record2object

protected java.lang.Object record2object(java.sql.ResultSet results,
                                         int position)
                                  throws java.lang.reflect.InvocationTargetException,
                                         java.lang.IllegalAccessException

Fetch a value from a database result set according to this descriptor's extraction mode. If mode is ExtractionMode.AUTO or NAME extract the field value by name. If the extraction causes an InvocationTargetExtraction and the extraction mode is AUTO, the descriptor is switched to INDEX mode and an extraction by index is immediatly attempted.

Parameters:

results - The ResultSet to extract data from

position - The index of the field to extract. Ignored in NAME mode. Passsing -1 forces extraction by name.

Returns:

The extracted value

Throws:

java.lang.reflect.InvocationTargetException

java.lang.IllegalAccessException

record2object

protected void record2object(java.lang.Object obj,
                             java.sql.ResultSet results,
                             int position)
                      throws java.sql.SQLException,
                             java.lang.IllegalAccessException,
                             java.lang.reflect.InvocationTargetException

Fetch a value from a database result set and copy it into an object according to this attribute descriptor

Throws:

java.sql.SQLException

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

getCreationValue

public java.lang.String getCreationValue(java.lang.Object obj,
                                         Database db)
                                  throws java.lang.IllegalAccessException,
                                         java.lang.reflect.InvocationTargetException

Returns a string representation of the passed object's value for this descriptor's attribute. If obj is null, returns "?", required for prepared statements.

Throws:

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

getParameter

public int getParameter(java.lang.Object obj,
                        PreparedOperation pop,
                        java.lang.String table,
                        int position)
                 throws java.lang.IllegalAccessException,
                        java.lang.reflect.InvocationTargetException,
                        java.sql.SQLException

Writes an attribute of the passed value object to a PreparedOperation

Parameters:

obj - the value object to read from

pop - the PreparedOperation to write to

table - the name of the database table, the operation refers to. This is only required in case of NULL attribute values, which require to retrieve the column type first. This is a nasty detail in the JDBC API which we must take care of. Some databases allow just to set type NULL in this case, but especially DB2 and Oracle do not. See method PreparedStatement.setNull(int, int) for further details.

position - index of the parameter in the prepared statement to write

Returns:

next parameter index (i.e. passed value + 1)

Throws:

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

java.sql.SQLException

wrapArrayTypedValue

protected java.lang.Object wrapArrayTypedValue(java.sql.Connection connection,
                                               java.lang.Object attrValue)
                                        throws java.sql.SQLException

Throws:

java.sql.SQLException