Package org.pjdbc.sql

Class CompositeTransformer

java.lang.Object

org.pjdbc.sql.AbstractJdbcTransformer

org.pjdbc.sql.CompositeTransformer

All Implemented Interfaces:

JdbcTransformer

public class CompositeTransformer
extends AbstractJdbcTransformer

Transformer that chains multiple JdbcTransformers together.

Transformers are applied in order: the output of one transformer becomes the input to the next. This allows composing simple transformers into complex transformation pipelines.

Example

 JdbcTransformer composite = new CompositeTransformer()
     .add(new SchemaTransformer("tenant_123"))
     .add(new WhereTransformer("deleted=false"))
     .add(new RenameTransformer().addRename("old_table", "new_table"));
 

See Also:

• invalid reference

  FilterDriver

Constructor Summary

Constructors

Constructor	Description
CompositeTransformer()	Create an empty CompositeTransformer.

Method Summary

Modifier and Type	Method	Description
CompositeTransformer	add(JdbcTransformer transformer)	Add a transformer to the chain.
boolean	isEmpty()	Check if this composite has any transformers.
int	size()	Get the number of transformers in this composite.
Object	transformParameter(int parameterIndex, Object value, int sqlType)	Default implementation returns parameter value unchanged.
Object	transformResultValue(int columnIndex, String columnName, Object value, int sqlType)	Default implementation returns result value unchanged.
String	transformSql(String sql)	Default implementation returns SQL unchanged.

Methods inherited from class java.lang.Object

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

Constructor Details

CompositeTransformer

public CompositeTransformer()

Create an empty CompositeTransformer.

Method Details

add

public CompositeTransformer add(JdbcTransformer transformer)

Add a transformer to the chain.

Parameters:

transformer - the transformer to add

Returns:

this transformer for chaining

isEmpty

public boolean isEmpty()

Check if this composite has any transformers.

Returns:

true if at least one transformer has been added

size

public int size()

Get the number of transformers in this composite.

Returns:

the number of transformers

transformSql

public String transformSql(String sql)
                    throws SQLException

Description copied from class: AbstractJdbcTransformer

Default implementation returns SQL unchanged.

Specified by:

transformSql in interface JdbcTransformer

Overrides:

transformSql in class AbstractJdbcTransformer

Parameters:

sql - Original SQL string

Returns:

Transformed SQL string

Throws:

SQLException - if transformation fails

transformParameter

public Object transformParameter(int parameterIndex,
 Object value,
 int sqlType)
                          throws SQLException

Description copied from class: AbstractJdbcTransformer

Default implementation returns parameter value unchanged.

Specified by:

transformParameter in interface JdbcTransformer

Overrides:

transformParameter in class AbstractJdbcTransformer

Parameters:

parameterIndex - 1-based parameter index

value - Original parameter value

sqlType - SQL type from java.sql.Types

Returns:

Transformed parameter value

Throws:

SQLException - if transformation fails

transformResultValue

public Object transformResultValue(int columnIndex,
 String columnName,
 Object value,
 int sqlType)
                            throws SQLException

Description copied from class: AbstractJdbcTransformer

Default implementation returns result value unchanged.

Specified by:

transformResultValue in interface JdbcTransformer

Overrides:

transformResultValue in class AbstractJdbcTransformer

Parameters:

columnIndex - 1-based column index

columnName - Column name (may be null if not available)

value - Original value from ResultSet

sqlType - SQL type from java.sql.Types

Returns:

Transformed value

Throws:

SQLException - if transformation fails