Class Projection

java.lang.Object
org.springframework.expression.spel.ast.SpelNodeImpl
org.springframework.expression.spel.ast.Projection
All Implemented Interfaces:
org.springframework.asm.Opcodes, SpelNode
public class Projection extends SpelNodeImpl
Represents projection, where a given operation is performed on all elements in some input sequence, returning a new sequence of the same size.

For example: {1,2,3,4,5,6,7,8,9,10}.![#isEven(#this)] evaluates to [n, y, n, y, n, y, n, y, n, y].

Null-safe Projection

Null-safe projection is supported via the '?.!' operator. For example, 'names?.![#this.length]' will evaluate to null if names is null and will otherwise evaluate to a sequence containing the lengths of the names. As of Spring Framework 7.0, null-safe projection also applies when performing projection on an Optional target. For example, if names is of type Optional<List<String>>, the expression 'names?.![#this.length]' will evaluate to null if names is null or empty and will otherwise evaluate to a sequence containing the lengths of the names, effectively names.get().stream().map(String::length).toList().

Since:
3.0
Author:
Andy Clement, Mark Fisher, Juergen Hoeller, Sam Brannen

  • Field Summary

    Fields inherited from class SpelNodeImpl

    children, exitTypeDescriptor

    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_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, ASM10_EXPERIMENTAL, ASM4, ASM5, ASM6, ASM7, ASM8, ASM9, 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, SOURCE_DEPRECATED, SOURCE_MASK, SWAP, 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, V22, V23, V24, V25, V9

  • Constructor Summary

    Constructors
    Constructor
    Description
    Projection(boolean nullSafe, int startPos, int endPos, SpelNodeImpl expression)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    TypedValue
    getValueInternal(ExpressionState state)
     
    protected ValueRef
    getValueRef(ExpressionState state)
     
    final boolean
    isNullSafe()
    Does this node represent a null-safe projection operation?
    String
    toStringAST()
    Return the string form of this AST node.

    Methods inherited from class SpelNodeImpl

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

    Methods inherited from class Object

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

    Methods inherited from interface SpelNode

    generateCode, isCompilable