com.mysema.query.types
Class MappingProjection<T>

java.lang.Object
  com.mysema.query.types.ExpressionBase<T>
      com.mysema.query.types.MappingProjection<T>

Type Parameters:

T - expression type

All Implemented Interfaces:

Expression<T>, FactoryExpression<T>, Serializable

public abstract class MappingProjection<T>
extends ExpressionBase<T>
implements FactoryExpression<T>

Projection template that allows implementing arbitrary mapping of rows to result objects.

Example

 MappingProjection<Pair<String,String>> mapping = new MappingProjection<Pair<String,String>>(Pair.class, str1, str2){
     @Override
     protected Pair<String, String> map(Tuple row) {
         return Pair.of(row.get(str1), row.get(str2));
     }            
 }; 
 

See Also:

Serialized Form

Constructor Summary

MappingProjection(Class<? super T> type, Expression<?>... args)
Create a new MappingProjection instance

MappingProjection(Class<? super T> type, Expression<?>[]... args)
Create a new MappingProjection instance

Method Summary

<R,C> R	accept(Visitor<R,C> v, C context) Accept the visitor with the given context
List<Expression<?>>	getArgs() Get the invocation arguments
protected abstract T	map(Tuple row) Creates a result object from the given row.
T	newInstance(Object... values) Create a projection with the given arguments

Methods inherited from class com.mysema.query.types.ExpressionBase

getType, hashCode, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.mysema.query.types.Expression

getType

Constructor Detail

MappingProjection

public MappingProjection(Class<? super T> type,
                         Expression<?>... args)

Create a new MappingProjection instance

Parameters:

type -

args -

MappingProjection

public MappingProjection(Class<? super T> type,
                         Expression<?>[]... args)

Create a new MappingProjection instance

Parameters:

type -

args -

Method Detail

newInstance

public T newInstance(Object... values)

Description copied from interface: FactoryExpression

Create a projection with the given arguments

Specified by:

newInstance in interface FactoryExpression<T>

Returns:

map

protected abstract T map(Tuple row)

Creates a result object from the given row.

Parameters:

row - The row to map

Returns:

The result object

getArgs

public List<Expression<?>> getArgs()

Description copied from interface: FactoryExpression

Get the invocation arguments

Specified by:

getArgs in interface FactoryExpression<T>

Returns:

accept

public <R,C> R accept(Visitor<R,C> v,
                      @Nullable
                      C context)

Description copied from interface: Expression

Accept the visitor with the given context

Specified by:

accept in interface Expression<T>

Type Parameters:

R - return type

C - context type

Parameters:

v - visitor

context - context of visit

Returns: