org.springframework.binding.expression.support
Class AbstractGetValueExpression

java.lang.Object
  extended by org.springframework.binding.expression.support.AbstractGetValueExpression
All Implemented Interfaces:
Expression

public abstract class AbstractGetValueExpression
extends Object
implements Expression

Trivial helper for concrete expression types that do not support setting their values. Simply throws an unsupported operation exception if setValue(Object, Object) is called. Subclasses must implement getValue(Object).

Author:
Keith Donald

Constructor Summary
AbstractGetValueExpression()
           
 
Method Summary
 String getExpressionString()
          Returns the original string used to create this expression, unmodified.
abstract  Object getValue(Object context)
          Evaluate this expression in the provided context and return the result of evaluation.
 Class getValueType(Object context)
          Returns the most general type that can be passed to the Expression.setValue(Object, Object) method for the given context.
 void setValue(Object context, Object value)
          Set this expression in the provided context to the value provided.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

AbstractGetValueExpression

public AbstractGetValueExpression()
Method Detail

getValue

public abstract Object getValue(Object context)
                         throws EvaluationException
Description copied from interface: Expression
Evaluate this expression in the provided context and return the result of evaluation.

Specified by:
getValue in interface Expression
Parameters:
context - the context to evaluate this expression in
Returns:
the evaluation result
Throws:
EvaluationException - an exception occurred during expression evaluation

setValue

public void setValue(Object context,
                     Object value)
              throws EvaluationException
Description copied from interface: Expression
Set this expression in the provided context to the value provided.

Specified by:
setValue in interface Expression
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

public Class getValueType(Object context)
Description copied from interface: Expression
Returns the most general type that can be passed to the Expression.setValue(Object, Object) method for the given context.

Specified by:
getValueType in interface Expression
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

getExpressionString

public String getExpressionString()
Description copied from interface: Expression
Returns the original string used to create this expression, unmodified.

Specified by:
getExpressionString in interface Expression
Returns:
the original expression string