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

Field Summary
- Fields inherited from class org.springframework.expression.spel.ast.SpelNodeImpl
  children, exitTypeDescriptor, pos
- Fields inherited from interface org.springframework.asm.Opcodes
  AALOAD, AASTORE, ACC_ABSTRACT, ACC_ANNOTATION, ACC_BRIDGE, ACC_DEPRECATED, ACC_ENUM, ACC_FINAL, ACC_INTERFACE, ACC_MANDATED, ACC_MODULE, ACC_NATIVE, ACC_OPEN, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STATIC_PHASE, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_SYNTHETIC, ACC_TRANSIENT, ACC_TRANSITIVE, ACC_VARARGS, ACC_VOLATILE, ACONST_NULL, ALOAD, ANEWARRAY, ARETURN, ARRAYLENGTH, ASM4, ASM5, ASM6, ASTORE, ATHROW, BALOAD, BASTORE, BIPUSH, CALOAD, CASTORE, CHECKCAST, D2F, D2I, D2L, DADD, DALOAD, DASTORE, DCMPG, DCMPL, DCONST_0, DCONST_1, DDIV, DLOAD, DMUL, DNEG, DOUBLE, DREM, DRETURN, DSTORE, DSUB, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, F_APPEND, F_CHOP, F_FULL, F_NEW, F_SAME, F_SAME1, F2D, F2I, F2L, FADD, FALOAD, FASTORE, FCMPG, FCMPL, FCONST_0, FCONST_1, FCONST_2, FDIV, FLOAD, FLOAT, FMUL, FNEG, FREM, FRETURN, FSTORE, FSUB, GETFIELD, GETSTATIC, GOTO, H_GETFIELD, H_GETSTATIC, H_INVOKEINTERFACE, H_INVOKESPECIAL, H_INVOKESTATIC, H_INVOKEVIRTUAL, H_NEWINVOKESPECIAL, H_PUTFIELD, H_PUTSTATIC, I2B, I2C, I2D, I2F, I2L, I2S, IADD, IALOAD, IAND, IASTORE, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, ICONST_M1, IDIV, IF_ACMPEQ, IF_ACMPNE, IF_ICMPEQ, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ICMPLT, IF_ICMPNE, IFEQ, IFGE, IFGT, IFLE, IFLT, IFNE, IFNONNULL, IFNULL, IINC, ILOAD, IMUL, INEG, INSTANCEOF, INTEGER, INVOKEDYNAMIC, INVOKEINTERFACE, INVOKESPECIAL, INVOKESTATIC, INVOKEVIRTUAL, IOR, IREM, IRETURN, ISHL, ISHR, ISTORE, ISUB, IUSHR, IXOR, JSR, L2D, L2F, L2I, LADD, LALOAD, LAND, LASTORE, LCMP, LCONST_0, LCONST_1, LDC, LDIV, LLOAD, LMUL, LNEG, LONG, LOOKUPSWITCH, LOR, LREM, LRETURN, LSHL, LSHR, LSTORE, LSUB, LUSHR, LXOR, MONITORENTER, MONITOREXIT, MULTIANEWARRAY, NEW, NEWARRAY, NOP, NULL, POP, POP2, PUTFIELD, PUTSTATIC, RET, RETURN, SALOAD, SASTORE, SIPUSH, SWAP, T_BOOLEAN, T_BYTE, T_CHAR, T_DOUBLE, T_FLOAT, T_INT, T_LONG, T_SHORT, TABLESWITCH, TOP, UNINITIALIZED_THIS, V1_1, V1_2, V1_3, V1_4, V1_5, V1_6, V1_7, V1_8, V1_9

Constructor Summary
Constructors
Constructor Description
Indexer(int pos, SpelNodeImpl expr)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`generateCode(MethodVisitor mv, CodeFlow cf)`	Generate the bytecode for this node into the supplied visitor.
`TypedValue`	`getValueInternal(ExpressionState state)`
`protected ValueRef`	`getValueRef(ExpressionState state)`
`boolean`	`isCompilable()`	Check whether a node can be compiled to bytecode.
`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
generateCodeForArgument, generateCodeForArguments, getChild, getChildCount, getEndPosition, getExitDescriptor, 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
  - 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
  - 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
  - getValueRef
```
protected ValueRef getValueRef(ExpressionState state)
                        throws EvaluationException
```
    Overrides:
    getValueRef in class SpelNodeImpl
    Throws:
    EvaluationException
  - 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 String toStringAST()
```
    Returns:
    the string form of this AST node

Class Indexer

Field Summary

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

Fields inherited from interface org.springframework.asm.Opcodes

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Constructor Detail

Indexer

Method Detail

getValueInternal

setValue

isWritable

getValueRef

isCompilable

generateCode

toStringAST