org.springframework.expression.spel.ast

Class PropertyOrFieldReference

java.lang.Object

org.springframework.expression.spel.ast.SpelNodeImpl

org.springframework.expression.spel.ast.PropertyOrFieldReference

All Implemented Interfaces:

Opcodes, SpelNode

public class PropertyOrFieldReference
extends SpelNodeImpl

Represents a simple property or field reference.

Since:

3.0

Author:

Andy Clement, Juergen Hoeller, Clark Duplichien

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	PropertyOrFieldReference.AccessorLValue

Field Summary

Fields

Modifier and Type	Field and Description
private PropertyAccessor	cachedReadAccessor
private PropertyAccessor	cachedWriteAccessor
private java.lang.String	name
private boolean	nullSafe

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
PropertyOrFieldReference(boolean nullSafe, java.lang.String propertyOrFieldName, int pos)

Method Summary

Modifier and Type	Method and Description
void	generateCode(MethodVisitor mv, CodeFlow cf) Generate the bytecode for this node into the supplied visitor.
java.lang.String	getName()
private java.util.List<PropertyAccessor>	getPropertyAccessorsToTry(java.lang.Object contextObject, java.util.List<PropertyAccessor> propertyAccessors) Determines the set of property resolvers that should be used to try and access a property on the specified target type.
TypedValue	getValueInternal(ExpressionState state)
private TypedValue	getValueInternal(TypedValue contextObject, EvaluationContext evalContext, boolean isAutoGrowNullReferences)
ValueRef	getValueRef(ExpressionState state)
boolean	isCompilable() Check whether a node can be compiled to bytecode.
boolean	isNullSafe()
boolean	isWritable(ExpressionState state) Determine if this expression node will support a setValue() call.
boolean	isWritableProperty(java.lang.String name, TypedValue contextObject, EvaluationContext evalContext)
private TypedValue	readProperty(TypedValue contextObject, EvaluationContext evalContext, java.lang.String name) Attempt to read the named property from the current context object.
void	setValue(ExpressionState state, java.lang.Object newValue) Evaluate the expression to a node and then set the new value on that node.
java.lang.String	toStringAST()
private void	writeProperty(TypedValue contextObject, EvaluationContext evalContext, java.lang.String name, java.lang.Object newValue)

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

Field Detail

nullSafe

private final boolean nullSafe

name

private final java.lang.String name

cachedReadAccessor

private volatile PropertyAccessor cachedReadAccessor

cachedWriteAccessor

private volatile PropertyAccessor cachedWriteAccessor

Constructor Detail

PropertyOrFieldReference

public PropertyOrFieldReference(boolean nullSafe,
                                java.lang.String propertyOrFieldName,
                                int pos)

Method Detail

isNullSafe

public boolean isNullSafe()

getName

public java.lang.String getName()

getValueRef

public ValueRef getValueRef(ExpressionState state)
                     throws EvaluationException

Overrides:

getValueRef in class SpelNodeImpl

Throws:

EvaluationException

getValueInternal

public TypedValue getValueInternal(ExpressionState state)
                            throws EvaluationException

Specified by:

getValueInternal in class SpelNodeImpl

Throws:

EvaluationException

getValueInternal

private TypedValue getValueInternal(TypedValue contextObject,
                                    EvaluationContext evalContext,
                                    boolean isAutoGrowNullReferences)
                             throws EvaluationException

Throws:

EvaluationException

setValue

public void setValue(ExpressionState state,
                     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

isWritable

public boolean isWritable(ExpressionState state)
                   throws EvaluationException

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:

state - 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

toStringAST

public java.lang.String toStringAST()

Returns:

the string form of this AST node

readProperty

private TypedValue readProperty(TypedValue contextObject,
                                EvaluationContext evalContext,
                                java.lang.String name)
                         throws EvaluationException

Attempt to read the named property from the current context object.

Returns:

the value of the property

Throws:

EvaluationException - if any problem accessing the property or it cannot be found

writeProperty

private void writeProperty(TypedValue contextObject,
                           EvaluationContext evalContext,
                           java.lang.String name,
                           java.lang.Object newValue)
                    throws EvaluationException

Throws:

EvaluationException

isWritableProperty

public boolean isWritableProperty(java.lang.String name,
                                  TypedValue contextObject,
                                  EvaluationContext evalContext)
                           throws EvaluationException

Throws:

EvaluationException

getPropertyAccessorsToTry

private java.util.List<PropertyAccessor> getPropertyAccessorsToTry(java.lang.Object contextObject,
                                                                   java.util.List<PropertyAccessor> propertyAccessors)

Determines the set of property resolvers that should be used to try and access a property on the specified target type. The resolvers are considered to be in an ordered list, however in the returned list any that are exact matches for the input target type (as opposed to 'general' resolvers that could work for any type) are placed at the start of the list. In addition, there are specific resolvers that exactly name the class in question and resolvers that name a specific class but it is a supertype of the class we have. These are put at the end of the specific resolvers set and will be tried after exactly matching accessors but before generic accessors.

Parameters:

contextObject - the object upon which property access is being attempted

Returns:

a list of resolvers that should be tried in order to access the property

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