org.springframework.expression.spel.ast

Class Indexer

  • All Implemented Interfaces:
    Opcodes, 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, Phillip Webb, Stephane Nicoll
    • Constructor Detail

    • Method Detail

      • setValue

        public void setValue(ExpressionState state,
                             @Nullable
                             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
        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
      • isCompilable

        public boolean isCompilable()
        Description copied from class: SpelNodeImpl
        Check whether a node can be compiled to bytecode. The reasoning in each node may be different but will typically involve checking whether the exit type descriptor of the node is known and any relevant child nodes are compilable.
        Overrides:
        isCompilable in class SpelNodeImpl
        Returns:
        true if this node can be compiled to bytecode
      • generateCode

        public void generateCode(MethodVisitor mv,
                                 CodeFlow cf)
        Description copied from class: SpelNodeImpl
        Generate the bytecode for this node into the supplied visitor. Context info about the current expression being compiled is available in the codeflow object. For example it will include information about the type of the object currently on the stack.
        Overrides:
        generateCode in class SpelNodeImpl
        Parameters:
        mv - the ASM MethodVisitor into which code should be generated
        cf - a context object with info about what is on the stack
      • toStringAST

        public java.lang.String toStringAST()
        Description copied from interface: SpelNode
        Return the string form the this AST node.
        Returns:
        the string form