org.springframework.expression.spel.ast
Class Indexer

java.lang.Object
  org.springframework.expression.spel.ast.SpelNodeImpl
      org.springframework.expression.spel.ast.Indexer

All Implemented Interfaces:

SpelNode

public class Indexer
extends SpelNodeImpl

An Indexer can index into some proceeding structure to access a particular piece of it. Supported structures are: strings/collections (lists/sets)/arrays

Since:

3.0

Author:

Andy Clement

Field Summary

Fields inherited from class org.springframework.expression.spel.ast.SpelNodeImpl

children, pos

Constructor Summary

Indexer(int pos, SpelNodeImpl expr)

Method Summary

TypedValue	getValueInternal(ExpressionState state)
boolean	isWritable(ExpressionState expressionState) Determine if this expression node will support a setValue() call.
void	setValue(ExpressionState state, Object newValue) Evaluate the expression to a node and then set the new value on that node.
String	toStringAST()

Methods inherited from class org.springframework.expression.spel.ast.SpelNodeImpl

getChild, getChildCount, getEndPosition, getObjectClass, getPreviousChild, getStartPosition, getTypedValue, getValue, getValue, nextChildIs

Methods inherited from class java.lang.Object

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

Constructor Detail

Indexer

public Indexer(int pos,
               SpelNodeImpl expr)

Method Detail

getValueInternal

public TypedValue getValueInternal(ExpressionState state)
                            throws EvaluationException

Specified by:

getValueInternal in class SpelNodeImpl

Throws:

EvaluationException

isWritable

public boolean isWritable(ExpressionState expressionState)
                   throws SpelEvaluationException

Description copied from interface: SpelNode

Determine if this expression node will support a setValue() call.

Specified by:

isWritable in interface SpelNode

Overrides:

isWritable in class SpelNodeImpl

Parameters:

expressionState - the current expression state (includes the context)

Returns:

true if the expression node will allow setValue()

Throws:

SpelEvaluationException

setValue

public void setValue(ExpressionState state,
                     Object newValue)
              throws EvaluationException

Description copied from interface: SpelNode

Evaluate the expression to a node and then set the new value on that node. For example, if the expression evaluates to a property reference then the property will be set to the new value.

Specified by:

setValue in interface SpelNode

Overrides:

setValue in class SpelNodeImpl

Parameters:

state - the current expression state (includes the context)

newValue - the new value

Throws:

EvaluationException - if any problem occurs evaluating the expression or setting the new value

toStringAST

public String toStringAST()

Specified by:

toStringAST in interface SpelNode

Specified by:

toStringAST in class SpelNodeImpl

Returns:

the string form of this AST node