程序包 cn.taketoday.expression.spel.ast

类 VariableReference

java.lang.Object

cn.taketoday.expression.spel.ast.SpelNodeImpl

cn.taketoday.expression.spel.ast.VariableReference

所有已实现的接口:

Opcodes, SpelNode

public class VariableReference
extends SpelNodeImpl

Represents a variable reference — for example, #someVar.

从以下版本开始:

4.0

作者:

Andy Clement, Sam Brannen, Harry Yang

嵌套类概要

嵌套类

修饰符和类型	类	说明
private static class	VariableReference.VariableRef

字段概要

字段

修饰符和类型	字段	说明
private final String	name
private static final String	ROOT	Root context object.
private static final String	THIS	Currently active context object.

从类继承的字段 cn.taketoday.expression.spel.ast.SpelNodeImpl

children, exitTypeDescriptor

从接口继承的字段 cn.taketoday.bytecode.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_RECORD, 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, 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, JAVA_VERSION, 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, PRIVATE_FINAL_STATIC, PUTFIELD, PUTSTATIC, RET, RETURN, SALOAD, SASTORE, SIPUSH, SOURCE_DEPRECATED, SOURCE_MASK, SWAP, SWITCH_STYLE_HASH, SWITCH_STYLE_HASHONLY, SWITCH_STYLE_TRIE, T_BOOLEAN, T_BYTE, T_CHAR, T_DOUBLE, T_FLOAT, T_INT, T_LONG, T_SHORT, TABLESWITCH, TOP, UNINITIALIZED_THIS, V_PREVIEW, V1_1, V1_2, V1_3, V1_4, V1_5, V1_6, V1_7, V1_8, V10, V11, V12, V13, V14, V15, V16, V17, V18, V19, V20, V21, V9

构造器概要

构造器

构造器	说明
VariableReference(String variableName, int startPos, int endPos)

方法概要

修饰符和类型	方法	说明
void	generateCode(MethodVisitor mv, CodeFlow cf)	Generate the bytecode for this node into the supplied visitor.
TypedValue	getValueInternal(ExpressionState state)
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.
private void	setExitTypeDescriptor(Object value)	Set the exit type descriptor for the supplied value.
TypedValue	setValueInternal(ExpressionState state, Supplier<TypedValue> valueSupplier)	Evaluate the expression to a node and then set the new value created by the specified Supplier on that node.
String	toStringAST()	Return the string form the this AST node.

从类继承的方法 cn.taketoday.expression.spel.ast.SpelNodeImpl

generateCodeForArgument, generateCodeForArguments, getChild, getChildCount, getEndPosition, getExitDescriptor, getObjectClass, getStartPosition, getTypedValue, getValue, getValue, nextChildIs, setValue

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

THIS

private static final String THIS

Currently active context object.

另请参阅:

• 常量字段值

ROOT

private static final String ROOT

Root context object.

另请参阅:

• 常量字段值

name

private final String name

构造器详细资料

VariableReference

public VariableReference(String variableName,
 int startPos,
 int endPos)

方法详细资料

getValueRef

public ValueRef getValueRef(ExpressionState state)
                     throws SpelEvaluationException

覆盖:

getValueRef 在类中 SpelNodeImpl

抛出:

SpelEvaluationException

getValueInternal

public TypedValue getValueInternal(ExpressionState state)
                            throws SpelEvaluationException

指定者:

getValueInternal 在类中 SpelNodeImpl

抛出:

SpelEvaluationException

setExitTypeDescriptor

private void setExitTypeDescriptor(@Nullable
 Object value)

Set the exit type descriptor for the supplied value.

If the value is null, we set the exit type descriptor to Object.

If the value's type is not public, generateCode(cn.taketoday.bytecode.MethodVisitor, cn.taketoday.bytecode.core.CodeFlow) would insert a checkcast to the non-public type in the generated byte code which would result in an IllegalAccessError when the compiled byte code is invoked. Thus, as a preventative measure, we set the exit type descriptor to Object in such cases. If resorting to Object is not sufficient, we could consider traversing the hierarchy to find the first public type.

setValueInternal

public TypedValue setValueInternal(ExpressionState state,
 Supplier<TypedValue> valueSupplier)
                            throws EvaluationException

从类复制的说明: SpelNodeImpl

Evaluate the expression to a node and then set the new value created by the specified Supplier on that node.

For example, if the expression evaluates to a property reference, then the property will be set to the new value.

Favor this method over SpelNodeImpl.setValue(ExpressionState, Object) when the value should be lazily computed.

By default, this method throws a SpelEvaluationException, effectively disabling this feature. Subclasses may override this method to provide an actual implementation.

覆盖:

setValueInternal 在类中 SpelNodeImpl

参数:

state - the current expression state (includes the context)

valueSupplier - a supplier of the new value

抛出:

EvaluationException - if any problem occurs evaluating the expression or setting the new value

toStringAST

public String toStringAST()

从接口复制的说明: SpelNode

Return the string form the this AST node.

返回:

the string form

isWritable

public boolean isWritable(ExpressionState expressionState)
                   throws SpelEvaluationException

从接口复制的说明: SpelNode

Determine if this expression node will support a setValue() call.

指定者:

isWritable 在接口中 SpelNode

覆盖:

isWritable 在类中 SpelNodeImpl

参数:

expressionState - the current expression state (includes the context)

返回:

true if the expression node will allow setValue()

抛出:

SpelEvaluationException

isCompilable

public boolean isCompilable()

从类复制的说明: 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.

覆盖:

isCompilable 在类中 SpelNodeImpl

返回:

true if this node can be compiled to bytecode

generateCode

public void generateCode(MethodVisitor mv,
 CodeFlow cf)

从类复制的说明: 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, e.g. including information about the type of the object currently on the stack.

覆盖:

generateCode 在类中 SpelNodeImpl

参数:

mv - the ASM MethodVisitor into which code should be generated

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