com.antelmann.sql
Class WrappedObjectRowMapper<T extends DBEntry>

java.lang.Object
  com.antelmann.sql.WrappedObjectRowMapper<T>

All Implemented Interfaces:

TransactionRequired, MappingInfo, ObjectRowMapper<T>, Wrapped<ObjectRowMapper<T>>

Direct Known Subclasses:

AddressableMapper

public class WrappedObjectRowMapper<T extends DBEntry>
extends Object
implements ObjectRowMapper<T>, Wrapped<ObjectRowMapper<T>>

eases the task of wrapping a given mapper and overriding only certain aspects of its behavior. All ObjectRowMapper-implementing methods are delegated to the embedded mapper. Often, a WrappedDBClassStoreMapping does a better job.

Since:

21.11.2008, 12:53:57

Author:

Holger Antelmann

See Also:

WrappedDBClassStoreMapping

Field Summary

protected ObjectRowMapper<T>

mapper

Constructor Summary

WrappedObjectRowMapper(ObjectRowMapper<T> mapper)

Method Summary

Stub<T>	extractStub(ResultSet rs, Class<T> typeClass)
Object	generateNewID()
String[]	getColumnNames() returns all the columns that are retrieved by the mapper when querying the database); the column names for the ID column and display column are included in the returned array.
String[]	getColumnsForTopic(Object topic) allows to determine whether there are any columns that are applicable for the given topic
int	getColumnSize(String column) allows to determine the size of the given column name.
Connection	getConnection()
String	getDisplayColumn() for use in stubs (in case a single column is used as a display value)
String	getDisplayNameForColumn(String column) returns a name suitable for display in a GUI if different from the column name used in the database
String	getIDColumn() specifies the column where the ID of the entry is mapped to
String	getMappingForTopic(Object topic) allows to determine whether a specific given topic maps to a distinct table, query or column name.
String[]	getRestrictMappedColumns() allows to limit the columns retrieved from a ResultSet when loading the data from a table query.
ResultSet	getResultSet(Filter<? super T> filter) constructs the ResultSet used for fetching entries that corresponds closest to the filter; note that the filter may be null, in which case the select statement should return all rows.
int	getSQLTypeforColumn(String column) allows to determine the SQL-type for a given column name
ResultSet	getStubResultSet(Filter<? super Stub<?>> filter) creates and returns the ResultSet used for fetching stubs that corresponds closest to the filter for extracting Stub entries.
String	getTableName() provides the name of the table that stores the data for the store
String	getTableQuery() if querying involves something different than just selecting all columns of the table, this method returns the string used to replace the table name in a query.
void	handleAfterStore(T entry, boolean isInsert) called by the store after a given entry is either inserted or updated, so that additional updates (other than providing the RowItem for storage) can take place.
T	instantiate(RowItem row) instantiates the DBEntry based on the properties in the given row.
RowItem	mapToRow(T object) generates a RowItem containing all relevant properties, so that it can be used to store the object into the database
ObjectRowMapper<T>	unwrap() returns the embedded mapper that was given to the constructor
void	verifyBeforeDelete(Object id) called by the store before a given entry is deleted, so that additional checks can easily be incorporated.
void	verifyBeforeStore(T entry, boolean isInsert) called by the store before a given entry is either inserted or updated, so that additional checks can easily be incorporated.

Methods inherited from class java.lang.Object

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

Field Detail

mapper

protected final ObjectRowMapper<T extends DBEntry> mapper

Constructor Detail

WrappedObjectRowMapper

public WrappedObjectRowMapper(ObjectRowMapper<T> mapper)

Method Detail

unwrap

public ObjectRowMapper<T> unwrap()

returns the embedded mapper that was given to the constructor

Specified by:

unwrap in interface Wrapped<ObjectRowMapper<T extends DBEntry>>

extractStub

public Stub<T> extractStub(ResultSet rs,
                           Class<T> typeClass)
                                    throws SQLException

Specified by:

extractStub in interface ObjectRowMapper<T extends DBEntry>

Throws:

SQLException

generateNewID

public Object generateNewID()
                     throws DatabaseException,
                            UnsupportedOperationException

Specified by:

generateNewID in interface ObjectRowMapper<T extends DBEntry>

Throws:

DatabaseException

UnsupportedOperationException

See Also:

DBClassStore.generateNewID(), SQLNumberGenerator, TransactionalNumberGenerator

getConnection

public Connection getConnection()

Specified by:

getConnection in interface ObjectRowMapper<T extends DBEntry>

getDisplayColumn

public String getDisplayColumn()

Description copied from interface: MappingInfo

for use in stubs (in case a single column is used as a display value)

Specified by:

getDisplayColumn in interface MappingInfo

getIDColumn

public String getIDColumn()

Description copied from interface: MappingInfo

specifies the column where the ID of the entry is mapped to

Specified by:

getIDColumn in interface MappingInfo

getResultSet

public ResultSet getResultSet(Filter<? super T> filter)
                       throws SQLException

Description copied from interface: ObjectRowMapper

constructs the ResultSet used for fetching entries that corresponds closest to the filter; note that the filter may be null, in which case the select statement should return all rows. The returned ResultSet should allow at least for all objects accepted by the filter; it may include more, which would then be filtered out by the filter itself.

Specified by:

getResultSet in interface ObjectRowMapper<T extends DBEntry>

Throws:

SQLException

getStubResultSet

public ResultSet getStubResultSet(Filter<? super Stub<?>> filter)
                           throws SQLException

Description copied from interface: ObjectRowMapper

creates and returns the ResultSet used for fetching stubs that corresponds closest to the filter for extracting Stub entries. The filter may be null.

Specified by:

getStubResultSet in interface ObjectRowMapper<T extends DBEntry>

Throws:

SQLException

getTableName

public String getTableName()

Description copied from interface: MappingInfo

provides the name of the table that stores the data for the store

Specified by:

getTableName in interface MappingInfo

See Also:

MappingInfo.getTableQuery()

getTableQuery

public String getTableQuery()

Description copied from interface: MappingInfo

if querying involves something different than just selecting all columns of the table, this method returns the string used to replace the table name in a query. The return value - if non-null - is used to create ResultSet objects, so that other columns than those merely present in the original table can be retrieved (e.g. through a join). If this value is null, the value from MappingInfo.getTableName() is used in all cases. If non-null, this variable would have a value like '(select a.field1, b.* from a, b where a.id=b.id) as t1'.

Specified by:

getTableQuery in interface MappingInfo

See Also:

MappingInfo.getTableName()

instantiate

public T instantiate(RowItem row)
                              throws Exception

Description copied from interface: ObjectRowMapper

instantiates the DBEntry based on the properties in the given row. The given row contains all the columns of the queried ResultSet unless the columns to be retrieved are restricted by ObjectRowMapper.getRestrictMappedColumns().

Specified by:

instantiate in interface ObjectRowMapper<T extends DBEntry>

Throws:

Exception

mapToRow

public RowItem mapToRow(T object)
                 throws WrongDataException

Description copied from interface: ObjectRowMapper

generates a RowItem containing all relevant properties, so that it can be used to store the object into the database

Specified by:

mapToRow in interface ObjectRowMapper<T extends DBEntry>

Throws:

WrongDataException

verifyBeforeDelete

public void verifyBeforeDelete(Object id)
                        throws DatabaseException,
                               SQLException

Description copied from interface: ObjectRowMapper

called by the store before a given entry is deleted, so that additional checks can easily be incorporated. This method would be called only from within an open transaction. Note that this method NOT called if DBClassStore.deleteEntries(Filter) is called and JDBCRowStore.isFastDelete() returns is true!

Specified by:

verifyBeforeDelete in interface ObjectRowMapper<T extends DBEntry>

Throws:

WrongDataException - if the deletion is not allowed for semantical reasons

DatabaseException

SQLException

verifyBeforeStore

public void verifyBeforeStore(T entry,
                              boolean isInsert)
                       throws DatabaseException,
                              SQLException

Description copied from interface: ObjectRowMapper

called by the store before a given entry is either inserted or updated, so that additional checks can easily be incorporated. This method would be called only from within an open transaction.

Specified by:

verifyBeforeStore in interface ObjectRowMapper<T extends DBEntry>

isInsert - if true, the entry is about to be inserted; if false, it is an update

Throws:

DatabaseException

SQLException

handleAfterStore

public void handleAfterStore(T entry,
                             boolean isInsert)
                      throws DatabaseException,
                             SQLException

Description copied from interface: ObjectRowMapper

called by the store after a given entry is either inserted or updated, so that additional updates (other than providing the RowItem for storage) can take place.

Specified by:

handleAfterStore in interface ObjectRowMapper<T extends DBEntry>

isInsert - if true, the entry is about to be inserted; if false, it is an update

Throws:

DatabaseException

SQLException

getMappingForTopic

public String getMappingForTopic(Object topic)

Description copied from interface: MappingInfo

allows to determine whether a specific given topic maps to a distinct table, query or column name.

Specified by:

getMappingForTopic in interface MappingInfo

Returns:

either a table name, a column name, a query string or null - depending on the given topic

getColumnsForTopic

public String[] getColumnsForTopic(Object topic)

Description copied from interface: MappingInfo

allows to determine whether there are any columns that are applicable for the given topic

Specified by:

getColumnsForTopic in interface MappingInfo

Returns:

an array of column names that apply to the given topic; the array may be empty but never null

getColumnNames

public String[] getColumnNames()

Description copied from interface: MappingInfo

returns all the columns that are retrieved by the mapper when querying the database); the column names for the ID column and display column are included in the returned array. Note that the return value refers to the columns in the table query; only if the query is null, the return value refers to the columns in the table itself.

Specified by:

getColumnNames in interface MappingInfo

Returns:

all columns that are retrieved by the mapper or null if this doesn't apply for this instance.

See Also:

MappingInfo.getTableName(), MappingInfo.getTableQuery(), MappingInfo.getIDColumn(), MappingInfo.getDisplayColumn()

getDisplayNameForColumn

public String getDisplayNameForColumn(String column)

Description copied from interface: MappingInfo

returns a name suitable for display in a GUI if different from the column name used in the database

Specified by:

getDisplayNameForColumn in interface MappingInfo

Returns:

a suitable display value for the given column or the given column itself if no better display name exists

getSQLTypeforColumn

public int getSQLTypeforColumn(String column)
                        throws IllegalArgumentException

Description copied from interface: MappingInfo

allows to determine the SQL-type for a given column name

Specified by:

getSQLTypeforColumn in interface MappingInfo

Returns:

the SQL-type for the given column

Throws:

IllegalArgumentException - if the given column is not known

See Also:

Types

getColumnSize

public int getColumnSize(String column)
                  throws IllegalArgumentException

Description copied from interface: MappingInfo

allows to determine the size of the given column name. For a text column, this is the maximum number of characters; for a number column, this specifies the precision.

Specified by:

getColumnSize in interface MappingInfo

Throws:

IllegalArgumentException - if the given column is not known

getRestrictMappedColumns

public String[] getRestrictMappedColumns()

Description copied from interface: ObjectRowMapper

allows to limit the columns retrieved from a ResultSet when loading the data from a table query. If the return value is null, all columns are retrieved without restriction. If the return value is an empty array, only the ID column is retrieved. If the return value is a non-empty array, only those columns are retrieved from the query that are contained in this array. The id column is always retrieved.

Specified by:

getRestrictMappedColumns in interface ObjectRowMapper<T extends DBEntry>

Returns:

an array of column names that limit which columns are retrieved from a ResultSet when extracting the data into a RowItem; null may be returned.

See Also:

ObjectRowMapper.instantiate(RowItem)