org.springframework.integration.expression

Class FunctionExpression<S>

java.lang.Object

org.springframework.integration.expression.FunctionExpression<S>

Type Parameters:

S - The evaluation context root object type.

All Implemented Interfaces:

Expression

public class FunctionExpression<S>
extends Object
implements Expression

An Expression that simply invokes Function.apply(Object) on its provided Function.

This is a powerful alternative to the SpEL, when Java 8 and its Lambda support is in use.

If the target component has support for an Expression property, a FunctionExpression can be specified instead of a SpelExpression as an alternative to evaluate the value from the Lambda, rather than runtime SpEL resolution.

The FunctionExpression is 'read-only', hence only getValue() operations are allowed. Any setValue(org.springframework.expression.EvaluationContext, java.lang.Object) operations and getValueType() related operations throw EvaluationException.

Since:

5.0

Author:

Artem Bilan, Gary Russell

Constructor Summary

Constructors

Constructor and Description
FunctionExpression(java.util.function.Function<S,?> function)

Method Summary

Modifier and Type	Method and Description
String	getExpressionString()
Object	getValue()
<T> T	getValue(Class<T> desiredResultType)
Object	getValue(EvaluationContext context)
<T> T	getValue(EvaluationContext context, Class<T> desiredResultType)
Object	getValue(EvaluationContext context, Object rootObject)
<T> T	getValue(EvaluationContext context, Object rootObject, Class<T> desiredResultType)
Object	getValue(Object rootObject)
<T> T	getValue(Object rootObject, Class<T> desiredResultType)
Class<?>	getValueType()
Class<?>	getValueType(EvaluationContext context)
Class<?>	getValueType(EvaluationContext context, Object rootObject)
Class<?>	getValueType(Object rootObject)
TypeDescriptor	getValueTypeDescriptor()
TypeDescriptor	getValueTypeDescriptor(EvaluationContext context)
TypeDescriptor	getValueTypeDescriptor(EvaluationContext context, Object rootObject)
TypeDescriptor	getValueTypeDescriptor(Object rootObject)
boolean	isWritable(EvaluationContext context)
boolean	isWritable(EvaluationContext context, Object rootObject)
boolean	isWritable(Object rootObject)
void	setValue(EvaluationContext context, Object value)
void	setValue(EvaluationContext context, Object rootObject, Object value)
void	setValue(Object rootObject, Object value)

Methods inherited from class java.lang.Object

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

Constructor Detail

FunctionExpression

public FunctionExpression(java.util.function.Function<S,?> function)

Method Detail

getValue

@Nullable
public Object getValue()
                          throws EvaluationException

Specified by:

getValue in interface Expression

Throws:

EvaluationException

getValue

@Nullable
public Object getValue(@Nullable
                                 Object rootObject)
                          throws EvaluationException

Specified by:

getValue in interface Expression

Throws:

EvaluationException

getValue

@Nullable
public <T> T getValue(@Nullable
                                Class<T> desiredResultType)
                         throws EvaluationException

Specified by:

getValue in interface Expression

Throws:

EvaluationException

getValue

@Nullable
public <T> T getValue(@Nullable
                                Object rootObject,
                                @Nullable
                                Class<T> desiredResultType)
                         throws EvaluationException

Specified by:

getValue in interface Expression

Throws:

EvaluationException

getValue

@Nullable
public Object getValue(EvaluationContext context)
                          throws EvaluationException

Specified by:

getValue in interface Expression

Throws:

EvaluationException

getValue

@Nullable
public Object getValue(EvaluationContext context,
                                 @Nullable
                                 Object rootObject)
                          throws EvaluationException

Specified by:

getValue in interface Expression

Throws:

EvaluationException

getValue

@Nullable
public <T> T getValue(EvaluationContext context,
                                @Nullable
                                Class<T> desiredResultType)
                         throws EvaluationException

Specified by:

getValue in interface Expression

Throws:

EvaluationException

getValue

@Nullable
public <T> T getValue(EvaluationContext context,
                                @Nullable
                                Object rootObject,
                                @Nullable
                                Class<T> desiredResultType)
                         throws EvaluationException

Specified by:

getValue in interface Expression

Throws:

EvaluationException

getValueType

public Class<?> getValueType()
                      throws EvaluationException

Specified by:

getValueType in interface Expression

Throws:

EvaluationException

getValueType

public Class<?> getValueType(@Nullable
                             Object rootObject)
                      throws EvaluationException

Specified by:

getValueType in interface Expression

Throws:

EvaluationException

getValueType

public Class<?> getValueType(EvaluationContext context)
                      throws EvaluationException

Specified by:

getValueType in interface Expression

Throws:

EvaluationException

getValueType

public Class<?> getValueType(EvaluationContext context,
                             @Nullable
                             Object rootObject)
                      throws EvaluationException

Specified by:

getValueType in interface Expression

Throws:

EvaluationException

getValueTypeDescriptor

public TypeDescriptor getValueTypeDescriptor()
                                      throws EvaluationException

Specified by:

getValueTypeDescriptor in interface Expression

Throws:

EvaluationException

getValueTypeDescriptor

public TypeDescriptor getValueTypeDescriptor(@Nullable
                                             Object rootObject)
                                      throws EvaluationException

Specified by:

getValueTypeDescriptor in interface Expression

Throws:

EvaluationException

getValueTypeDescriptor

public TypeDescriptor getValueTypeDescriptor(EvaluationContext context)
                                      throws EvaluationException

Specified by:

getValueTypeDescriptor in interface Expression

Throws:

EvaluationException

getValueTypeDescriptor

public TypeDescriptor getValueTypeDescriptor(EvaluationContext context,
                                             @Nullable
                                             Object rootObject)
                                      throws EvaluationException

Specified by:

getValueTypeDescriptor in interface Expression

Throws:

EvaluationException

setValue

public void setValue(EvaluationContext context,
                     @Nullable
                     Object value)
              throws EvaluationException

Specified by:

setValue in interface Expression

Throws:

EvaluationException

setValue

public void setValue(@Nullable
                     Object rootObject,
                     @Nullable
                     Object value)
              throws EvaluationException

Specified by:

setValue in interface Expression

Throws:

EvaluationException

setValue

public void setValue(EvaluationContext context,
                     @Nullable
                     Object rootObject,
                     @Nullable
                     Object value)
              throws EvaluationException

Specified by:

setValue in interface Expression

Throws:

EvaluationException

isWritable

public boolean isWritable(EvaluationContext context)
                   throws EvaluationException

Specified by:

isWritable in interface Expression

Throws:

EvaluationException

isWritable

public boolean isWritable(EvaluationContext context,
                          @Nullable
                          Object rootObject)
                   throws EvaluationException

Specified by:

isWritable in interface Expression

Throws:

EvaluationException

isWritable

public boolean isWritable(@Nullable
                          Object rootObject)
                   throws EvaluationException

Specified by:

isWritable in interface Expression

Throws:

EvaluationException

getExpressionString

public final String getExpressionString()

Specified by:

getExpressionString in interface Expression