org.springframework.binding.expression

Interface Expression

All Known Implementing Classes:

AbstractGetValueExpression, BeanWrapperExpression, CollectionAddingExpression, CompositeStringExpression, ELExpression, LiteralExpression, SpringELExpression, StaticExpression

public interface Expression

An expression capable of evaluating itself against context objects. Encapsulates the details of a previously parsed expression string. Provides a common abstraction for expression evaluation independent of any language like Spring EL or the Unified EL.

Author:

Keith Donald

Method Summary

Modifier and Type	Method and Description
java.lang.String	getExpressionString() Returns the original string used to create this expression, unmodified.
java.lang.Object	getValue(java.lang.Object context) Evaluate this expression in the provided context and return the result of evaluation.
java.lang.Class<?>	getValueType(java.lang.Object context) Returns the most general type that can be passed to the setValue(Object, Object) method for the given context.
void	setValue(java.lang.Object context, java.lang.Object value) Set this expression in the provided context to the value provided.

Method Detail

getValue

java.lang.Object getValue(java.lang.Object context)
                   throws EvaluationException

Evaluate this expression in the provided context and return the result of evaluation.

Parameters:

context - the context to evaluate this expression in

Returns:

the evaluation result

Throws:

EvaluationException - an exception occurred during expression evaluation

setValue

void setValue(java.lang.Object context,
              java.lang.Object value)
       throws EvaluationException

Set this expression in the provided context to the value provided.

Parameters:

context - the context on which the new value should be set

value - the new value to set

Throws:

EvaluationException - an exception occurred during expression evaluation

getValueType

java.lang.Class<?> getValueType(java.lang.Object context)
                         throws EvaluationException

Returns the most general type that can be passed to the setValue(Object, Object) method for the given context.

Parameters:

context - the context to evaluate

Returns:

the most general type of value that can be set on this context, or null if the type information cannot be determined

Throws:

EvaluationException - an exception occurred during expression evaluation

getExpressionString

java.lang.String getExpressionString()

Returns the original string used to create this expression, unmodified.

Returns:

the original expression string