Package org.springframework.expression.spel

Interface SpelNode

All Known Implementing Classes:
Assign, BeanReference, BooleanLiteral, CompoundExpression, ConstructorReference, Elvis, FloatLiteral, FunctionReference, Identifier, Indexer, InlineList, InlineMap, IntLiteral, Literal, LongLiteral, MethodReference, NullLiteral, OpAnd, OpDec, OpDivide, OpEQ, Operator, OperatorBetween, OperatorInstanceof, OperatorMatches, OperatorNot, OperatorPower, OpGE, OpGT, OpInc, OpLE, OpLT, OpMinus, OpModulus, OpMultiply, OpNE, OpOr, OpPlus, Projection, PropertyOrFieldReference, QualifiedIdentifier, RealLiteral, Selection, SpelNodeImpl, StringLiteral, Ternary, TypeReference, VariableReference
public interface SpelNode
Represents a node in the AST for a parsed expression.
Since:
3.0
Author:
Andy Clement

  • Method Summary

    Modifier and Type
    Method
    Description
    SpelNode
    getChild(int index)
    Helper method that returns a SpelNode rather than an Antlr Tree node.
    int
    getChildCount()
    Return the number of children under this node.
    int
    getEndPosition()
    Return the end position of this AST node in the expression string.
    Class<?>
    getObjectClass(Object obj)
    Determine the class of the object passed in, unless it is already a class object.
    int
    getStartPosition()
    Return the start position of this AST node in the expression string.
    TypedValue
    getTypedValue(ExpressionState expressionState)
    Evaluate the expression node in the context of the supplied expression state and return the typed value.
    Object
    getValue(ExpressionState expressionState)
    Evaluate the expression node in the context of the supplied expression state and return the value.
    boolean
    isWritable(ExpressionState expressionState)
    Determine if this expression node will support a setValue() call.
    void
    setValue(ExpressionState expressionState, Object newValue)
    Evaluate the expression to a node and then set the new value on that node.
    String
    toStringAST()
    Return the string form of this AST node.

  • Method Details

    • getValue

      @Nullable Object getValue(ExpressionState expressionState) throws EvaluationException
      Evaluate the expression node in the context of the supplied expression state and return the value.
      Parameters:
      expressionState - the current expression state (includes the context)
      Returns:
      the value of this node evaluated against the specified state
      Throws:
      EvaluationException

    • getTypedValue

      TypedValue getTypedValue(ExpressionState expressionState) throws EvaluationException
      Evaluate the expression node in the context of the supplied expression state and return the typed value.
      Parameters:
      expressionState - the current expression state (includes the context)
      Returns:
      the type value of this node evaluated against the specified state
      Throws:
      EvaluationException

    • isWritable

      boolean isWritable(ExpressionState expressionState) throws EvaluationException
      Determine if this expression node will support a setValue() call.
      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

      void setValue(ExpressionState expressionState, @Nullable Object newValue) throws EvaluationException
      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.
      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

    • toStringAST

      String toStringAST()
      Return the string form of this AST node.
      Returns:
      the string form

    • getChildCount

      int getChildCount()
      Return the number of children under this node.
      Returns:
      the child count

    • getChild

      SpelNode getChild(int index)
      Helper method that returns a SpelNode rather than an Antlr Tree node.
      Returns:
      the child node cast to a SpelNode

    • getObjectClass

      @Nullable Class<?> getObjectClass(@Nullable Object obj)
      Determine the class of the object passed in, unless it is already a class object.
      Parameters:
      obj - the object that the caller wants the class of
      Returns:
      the class of the object if it is not already a class object, or null if the object is null

    • getStartPosition

      int getStartPosition()
      Return the start position of this AST node in the expression string.
      Returns:
      the start position

    • getEndPosition

      int getEndPosition()
      Return the end position of this AST node in the expression string.
      Returns:
      the end position