类 Elvis
- java.lang.Object
- org.springframework.expression.spel.ast.SpelNodeImpl
- org.springframework.expression.spel.ast.Elvis
public class Elvis extends SpelNodeImpl
Represents the elvis operator ?:. For an expression "a?:b" if a is not null, the value of the expression is "a", if a is null then the value of the expression is "b".- 从以下版本开始:
- 3.0
- 作者:
- Andy Clement, Juergen Hoeller
字段概要
从类继承的字段 org.springframework.expression.spel.ast.SpelNodeImpl
children, exitTypeDescriptor, pos
从接口继承的字段 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
构造器概要
构造器 构造器 说明 Elvis(int pos, SpelNodeImpl... args)
方法概要
所有方法 实例方法 具体方法 修饰符和类型 方法 说明 voidgenerateCode(MethodVisitor mv, CodeFlow cf)Generate the bytecode for this node into the supplied visitor.TypedValuegetValueInternal(ExpressionState state)Evaluate the condition and if not null, return it.booleanisCompilable()Check whether a node can be compiled to bytecode.StringtoStringAST()从类继承的方法 org.springframework.expression.spel.ast.SpelNodeImpl
generateCodeForArgument, generateCodeForArguments, getChild, getChildCount, getEndPosition, getExitDescriptor, getObjectClass, getPreviousChild, getStartPosition, getTypedValue, getValue, getValue, getValueRef, isWritable, nextChildIs, setValue
构造器详细资料
Elvis
public Elvis(int pos, SpelNodeImpl... args)
方法详细资料
getValueInternal
public TypedValue getValueInternal(ExpressionState state) throws EvaluationException
Evaluate the condition and if not null, return it. If it is null, return the other value.- 指定者:
getValueInternal在类中SpelNodeImpl- 参数:
state- the expression state- 抛出:
EvaluationException- if the condition does not evaluate correctly to a boolean or there is a problem executing the chosen alternative
toStringAST
public String toStringAST()
- 返回:
- the string form of this AST node
isCompilable
public boolean isCompilable()
从类复制的说明:SpelNodeImplCheck 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:
trueif this node can be compiled to bytecode
generateCode
public void generateCode(MethodVisitor mv, CodeFlow cf)
从类复制的说明:SpelNodeImplGenerate 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.- 覆盖:
generateCode在类中SpelNodeImpl- 参数:
mv- the ASM MethodVisitor into which code should be generatedcf- a context object with info about what is on the stack