org.springframework.expression.spel.ast
Class SpelNodeImpl

java.lang.Object
  org.antlr.runtime.tree.BaseTree
      org.antlr.runtime.tree.CommonTree
          org.springframework.expression.spel.ast.SpelNodeImpl

All Implemented Interfaces:

java.io.Serializable, org.antlr.runtime.tree.Tree, CommonTypeDescriptors, SpelNode

Direct Known Subclasses:

Assign, CompoundExpression, ConstructorReference, Dot, EmptySpelNode, FunctionReference, Identifier, Indexer, Literal, MethodReference, Operator, OperatorNot, Projection, PropertyOrFieldReference, QualifiedIdentifier, Selection, Ternary, TypeReference, VariableReference

public abstract class SpelNodeImpl
extends org.antlr.runtime.tree.CommonTree
implements SpelNode, java.io.Serializable, CommonTypeDescriptors

The common supertype of all AST nodes in a parsed Spring Expression Language format expression.

Since:

3.0

Author:

Andy Clement

See Also:

Serialized Form

Field Summary

Fields inherited from class org.antlr.runtime.tree.CommonTree

startIndex, stopIndex, token

Fields inherited from class org.antlr.runtime.tree.BaseTree

children

Fields inherited from interface org.springframework.expression.spel.ast.CommonTypeDescriptors

BOOLEAN_TYPE_DESCRIPTOR, BYTE_TYPE_DESCRIPTOR, CHARACTER_TYPE_DESCRIPTOR, CLASS_TYPE_DESCRIPTOR, DOUBLE_TYPE_DESCRIPTOR, FLOAT_TYPE_DESCRIPTOR, INTEGER_TYPE_DESCRIPTOR, LONG_TYPE_DESCRIPTOR, OBJECT_TYPE_DESCRIPTOR, SHORT_TYPE_DESCRIPTOR, STRING_TYPE_DESCRIPTOR

Fields inherited from interface org.antlr.runtime.tree.Tree

INVALID_NODE

Constructor Summary

protected

SpelNodeImpl(org.antlr.runtime.Token payload) The Antlr parser uses this constructor to build SpelNodes.

Method Summary

SpelNodeImpl	getChild(int index) Helper method that returns a SpelNode rather than an Antlr Tree node.
java.lang.Class<?>	getObjectClass(java.lang.Object obj) Determine the class of the object passed in, unless it is already a class object.
int	getStartPosition()
protected java.lang.String	getTokenName()
java.lang.Object	getValue(ExpressionState expressionState) Evaluate the expression node in the context of the supplied expression state and return the value.
protected <T> T	getValue(ExpressionState state, java.lang.Class<T> desiredReturnType)
abstract TypedValue	getValueInternal(ExpressionState expressionState)
boolean	isWritable(ExpressionState expressionState) Determine if this expression node will support a setValue() call.
void	setValue(ExpressionState expressionState, java.lang.Object newValue) Evaluate the expression to a node and then set the new value on that node.
abstract java.lang.String	toStringAST()

Methods inherited from class org.antlr.runtime.tree.CommonTree

dupNode, getCharPositionInLine, getLine, getText, getToken, getTokenStartIndex, getTokenStopIndex, getType, isNil, setTokenStartIndex, setTokenStopIndex, toString

Methods inherited from class org.antlr.runtime.tree.BaseTree

addChild, addChildren, createChildrenList, deleteChild, dupTree, getChildCount, getFirstChildWithType, setChild, toStringTree

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.expression.spel.SpelNode

getChildCount

Constructor Detail

SpelNodeImpl

protected SpelNodeImpl(org.antlr.runtime.Token payload)

The Antlr parser uses this constructor to build SpelNodes.

Parameters:

payload - the token for the node that has been parsed

Method Detail

getValue

public final java.lang.Object getValue(ExpressionState expressionState)
                                throws EvaluationException

Description copied from interface: SpelNode

Evaluate the expression node in the context of the supplied expression state and return the value.

Specified by:

getValue in interface SpelNode

Parameters:

expressionState - the current expression state (includes the context)

Returns:

the value of this node evaluated against the specified state

Throws:

EvaluationException

isWritable

public boolean isWritable(ExpressionState expressionState)
                   throws EvaluationException

Description copied from interface: SpelNode

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

Specified by:

isWritable in interface SpelNode

Parameters:

expressionState - the current expression state (includes the context)

Returns:

true if the expression node will allow setValue()

Throws:

EvaluationException - if something went wrong trying to determine if the node supports writing

setValue

public void setValue(ExpressionState expressionState,
                     java.lang.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

Parameters:

expressionState - 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

getTokenName

protected java.lang.String getTokenName()

getChild

public SpelNodeImpl getChild(int index)

Description copied from interface: SpelNode

Helper method that returns a SpelNode rather than an Antlr Tree node.

Specified by:

getChild in interface org.antlr.runtime.tree.Tree

Specified by:

getChild in interface SpelNode

Overrides:

getChild in class org.antlr.runtime.tree.BaseTree

Returns:

the child node cast to a SpelNode

getObjectClass

public java.lang.Class<?> getObjectClass(java.lang.Object obj)

Description copied from interface: SpelNode

Determine the class of the object passed in, unless it is already a class object.

Specified by:

getObjectClass in interface SpelNode

Returns:

the class of the object if it is not already a class object, or null if the object is null

getValue

protected final <T> T getValue(ExpressionState state,
                               java.lang.Class<T> desiredReturnType)
                    throws EvaluationException

Throws:

EvaluationException

getStartPosition

public int getStartPosition()

Specified by:

getStartPosition in interface SpelNode

Returns:

the start position of this Ast node in the expression string

getValueInternal

public abstract TypedValue getValueInternal(ExpressionState expressionState)
                                     throws EvaluationException

Throws:

EvaluationException

toStringAST

public abstract java.lang.String toStringAST()

Specified by:

toStringAST in interface SpelNode

Returns:

the string form of this AST node