Class SpelNodeImpl
- java.lang.Object
- org.springframework.expression.spel.ast.SpelNodeImpl
- Direct Known Subclasses:
Assign
,BeanReference
,CompoundExpression
,ConstructorReference
,Elvis
,FunctionReference
,Identifier
,Indexer
,InlineList
,InlineMap
,Literal
,MethodReference
,Operator
,OperatorNot
,Projection
,PropertyOrFieldReference
,QualifiedIdentifier
,Selection
,Ternary
,TypeReference
,VariableReference
public abstract class SpelNodeImpl extends Object implements SpelNode, Opcodes
The common supertype of all AST nodes in a parsed Spring Expression Language format expression.- Since:
- 3.0
- Author:
- Andy Clement
Field Summary
Fields Modifier and Type Field Description protected SpelNodeImpl[]
children
protected String
exitTypeDescriptor
Indicates the type descriptor for the result of this expression node.protected int
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 SpelNodeImpl(int pos, SpelNodeImpl... operands)
Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods Modifier and Type Method Description void
generateCode(MethodVisitor mv, CodeFlow cf)
Generate the bytecode for this node into the supplied visitor.protected static void
generateCodeForArgument(MethodVisitor mv, CodeFlow cf, SpelNodeImpl argument, String paramDesc)
Ask an argument to generate its bytecode and then follow it up with any boxing/unboxing/checkcasting to ensure it matches the expected parameter descriptor.protected static void
generateCodeForArguments(MethodVisitor mv, CodeFlow cf, Member member, SpelNodeImpl[] arguments)
Generate code that handles building the argument values for the specified method.SpelNode
getChild(int index)
Helper method that returns a SpelNode rather than an Antlr Tree node.int
getChildCount()
int
getEndPosition()
String
getExitDescriptor()
Class<?>
getObjectClass(Object obj)
Determine the class of the object passed in, unless it is already a class object.protected SpelNodeImpl
getPreviousChild()
Deprecated.int
getStartPosition()
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.protected <T> T
getValue(ExpressionState state, Class<T> desiredReturnType)
abstract TypedValue
getValueInternal(ExpressionState expressionState)
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.protected boolean
nextChildIs(Class<?>... clazzes)
void
setValue(ExpressionState expressionState, Object newValue)
Evaluate the expression to a node and then set the new value on that node.Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.springframework.expression.spel.SpelNode
toStringAST
Field Detail
pos
protected int pos
children
protected SpelNodeImpl[] children
exitTypeDescriptor
protected volatile String exitTypeDescriptor
Indicates the type descriptor for the result of this expression node. This is set as soon as it is known. For a literal node it is known immediately. For a property access or method invocation it is known after one evaluation of that node.The descriptor is like the bytecode form but is slightly easier to work with. It does not include the trailing semicolon (for non array reference types). Some examples: Ljava/lang/String, I, [I
Constructor Detail
SpelNodeImpl
public SpelNodeImpl(int pos, SpelNodeImpl... operands)
Method Detail
getPreviousChild
@Deprecated protected SpelNodeImpl getPreviousChild()
Deprecated.
nextChildIs
protected boolean nextChildIs(Class<?>... clazzes)
- Returns:
- true if the next child is one of the specified classes
getValue
public final 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 interfaceSpelNode
- Parameters:
expressionState
- the current expression state (includes the context)- Returns:
- the value of this node evaluated against the specified state
- Throws:
EvaluationException
getTypedValue
public final TypedValue getTypedValue(ExpressionState expressionState) throws EvaluationException
Description copied from interface:SpelNode
Evaluate the expression node in the context of the supplied expression state and return the typed value.- Specified by:
getTypedValue
in interfaceSpelNode
- Parameters:
expressionState
- the current expression state (includes the context)- Returns:
- the type 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 interfaceSpelNode
- 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, 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 interfaceSpelNode
- 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
getChild
public SpelNode getChild(int index)
Description copied from interface:SpelNode
Helper method that returns a SpelNode rather than an Antlr Tree node.
getChildCount
public int getChildCount()
- Specified by:
getChildCount
in interfaceSpelNode
- Returns:
- the number of children under this node
getObjectClass
public Class<?> getObjectClass(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 interfaceSpelNode
- 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 isnull
getValue
protected final <T> T getValue(ExpressionState state, Class<T> desiredReturnType) throws EvaluationException
- Throws:
EvaluationException
getStartPosition
public int getStartPosition()
- Specified by:
getStartPosition
in interfaceSpelNode
- Returns:
- the start position of this Ast node in the expression string
getEndPosition
public int getEndPosition()
- Specified by:
getEndPosition
in interfaceSpelNode
- Returns:
- the end position of this Ast node in the expression string
getValueRef
protected ValueRef getValueRef(ExpressionState state) throws EvaluationException
- Throws:
EvaluationException
isCompilable
public boolean isCompilable()
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.- Returns:
true
if this node can be compiled to bytecode
generateCode
public void generateCode(MethodVisitor mv, CodeFlow cf)
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.- Parameters:
mv
- the ASM MethodVisitor into which code should be generatedcf
- a context object with info about what is on the stack
getExitDescriptor
public String getExitDescriptor()
getValueInternal
public abstract TypedValue getValueInternal(ExpressionState expressionState) throws EvaluationException
- Throws:
EvaluationException
generateCodeForArguments
protected static void generateCodeForArguments(MethodVisitor mv, CodeFlow cf, Member member, SpelNodeImpl[] arguments)
Generate code that handles building the argument values for the specified method. This method will take account of whether the invoked method is a varargs method and if it is then the argument values will be appropriately packaged into an array.- Parameters:
mv
- the method visitor where code should be generatedcf
- the current codeflowmember
- the method or constructor for which arguments are being setuparguments
- the expression nodes for the expression supplied argument values
generateCodeForArgument
protected static void generateCodeForArgument(MethodVisitor mv, CodeFlow cf, SpelNodeImpl argument, String paramDesc)
Ask an argument to generate its bytecode and then follow it up with any boxing/unboxing/checkcasting to ensure it matches the expected parameter descriptor.