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:

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_NATIVE, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_SYNTHETIC, ACC_TRANSIENT, ACC_VARARGS, ACC_VOLATILE, ACONST_NULL, ALOAD, ANEWARRAY, ARETURN, ARRAYLENGTH, ASM4, ASM5, 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

Constructor Summary

Constructors

Constructor and Description
Indexer(int pos, SpelNodeImpl expr)

Method Summary

Modifier and Type	Method and Description
void	generateCode(MethodVisitor mv, CodeFlow codeflow) 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

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 codeflow)

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

codeflow - a context object with info about what is on the stack

toStringAST

public String toStringAST()

Returns:

the string form of this AST node