From d4495a56542276d6ea9a09d6b61c0e30cb75188c Mon Sep 17 00:00:00 2001 From: Sam Brannen <104798+sbrannen@users.noreply.github.com> Date: Fri, 22 Mar 2024 16:22:41 +0100 Subject: [PATCH 1/2] Revise PropertyOrFieldReference since isNullSafe() is not final --- .../expression/spel/ast/PropertyOrFieldReference.java | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/spring-expression/src/main/java/org/springframework/expression/spel/ast/PropertyOrFieldReference.java b/spring-expression/src/main/java/org/springframework/expression/spel/ast/PropertyOrFieldReference.java index b84c78210452..a033f6c14b49 100644 --- a/spring-expression/src/main/java/org/springframework/expression/spel/ast/PropertyOrFieldReference.java +++ b/spring-expression/src/main/java/org/springframework/expression/spel/ast/PropertyOrFieldReference.java @@ -181,7 +181,7 @@ private TypedValue readProperty(TypedValue contextObject, EvaluationContext eval throws EvaluationException { Object targetObject = contextObject.getValue(); - if (targetObject == null && this.nullSafe) { + if (targetObject == null && isNullSafe()) { return TypedValue.NULL; } @@ -233,7 +233,7 @@ private void writeProperty( TypedValue contextObject, EvaluationContext evalContext, String name, @Nullable Object newValue) throws EvaluationException { - if (contextObject.getValue() == null && this.nullSafe) { + if (contextObject.getValue() == null && isNullSafe()) { return; } if (contextObject.getValue() == null) { @@ -353,7 +353,7 @@ public void generateCode(MethodVisitor mv, CodeFlow cf) { } Label skipIfNull = null; - if (this.nullSafe) { + if (isNullSafe()) { mv.visitInsn(DUP); skipIfNull = new Label(); Label continueLabel = new Label(); @@ -381,7 +381,7 @@ void setExitTypeDescriptor(String descriptor) { // If this property or field access would return a primitive - and yet // it is also marked null safe - then the exit type descriptor must be // promoted to the box type to allow a null value to be passed on - if (this.nullSafe && CodeFlow.isPrimitive(descriptor)) { + if (isNullSafe() && CodeFlow.isPrimitive(descriptor)) { this.originalPrimitiveExitTypeDescriptor = descriptor; this.exitTypeDescriptor = CodeFlow.toBoxedDescriptor(descriptor); } From f941754db668be5621b18c62e9a20aa9486c6d06 Mon Sep 17 00:00:00 2001 From: Sam Brannen <104798+sbrannen@users.noreply.github.com> Date: Fri, 22 Mar 2024 16:29:38 +0100 Subject: [PATCH 2/2] Introduce isNullSafe() in SpelNodeImpl Prior to this commit, MethodReference and PropertyOrFieldReference already defined local isNullSafe() methods, but we need identical methods in Selection, Projection, and Indexer, and we may potentially need null-safe support for additional operators in the future. To address the common need for an is-null-safe check, this commit introduces an isNullSafe() method in SpelNodeImpl with a default implementation that returns false. Closes gh-32516 --- .../expression/spel/ast/CompoundExpression.java | 14 ++++++-------- .../expression/spel/ast/MethodReference.java | 3 ++- .../spel/ast/PropertyOrFieldReference.java | 1 + .../expression/spel/ast/SpelNodeImpl.java | 10 ++++++++++ 4 files changed, 19 insertions(+), 9 deletions(-) diff --git a/spring-expression/src/main/java/org/springframework/expression/spel/ast/CompoundExpression.java b/spring-expression/src/main/java/org/springframework/expression/spel/ast/CompoundExpression.java index 8a540a908dc6..593e5164b0ec 100644 --- a/spring-expression/src/main/java/org/springframework/expression/spel/ast/CompoundExpression.java +++ b/spring-expression/src/main/java/org/springframework/expression/spel/ast/CompoundExpression.java @@ -1,5 +1,5 @@ /* - * Copyright 2002-2023 the original author or authors. + * Copyright 2002-2024 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -24,7 +24,6 @@ import org.springframework.expression.spel.CodeFlow; import org.springframework.expression.spel.ExpressionState; import org.springframework.expression.spel.SpelEvaluationException; -import org.springframework.expression.spel.SpelNode; /** * Represents a DOT separated expression sequence, such as @@ -120,14 +119,13 @@ public String toStringAST() { for (int i = 0; i < getChildCount(); i++) { sb.append(getChild(i).toStringAST()); if (i < getChildCount() - 1) { - SpelNode nextChild = getChild(i + 1); + SpelNodeImpl nextChild = this.children[i + 1]; + if (nextChild.isNullSafe()) { + sb.append("?."); + } // Don't append a '.' if the next child is an Indexer. // For example, we want 'myVar[0]' instead of 'myVar.[0]'. - if (!(nextChild instanceof Indexer)) { - if ((nextChild instanceof MethodReference methodRef && methodRef.isNullSafe()) || - (nextChild instanceof PropertyOrFieldReference pofRef && pofRef.isNullSafe())) { - sb.append('?'); - } + else if (!(nextChild instanceof Indexer)) { sb.append('.'); } } diff --git a/spring-expression/src/main/java/org/springframework/expression/spel/ast/MethodReference.java b/spring-expression/src/main/java/org/springframework/expression/spel/ast/MethodReference.java index 3b60cff3ae3e..ed0cdca8846f 100644 --- a/spring-expression/src/main/java/org/springframework/expression/spel/ast/MethodReference.java +++ b/spring-expression/src/main/java/org/springframework/expression/spel/ast/MethodReference.java @@ -1,5 +1,5 @@ /* - * Copyright 2002-2023 the original author or authors. + * Copyright 2002-2024 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -77,6 +77,7 @@ public MethodReference(boolean nullSafe, String methodName, int startPos, int en * Does this node represent a null-safe method reference? * @since 6.0.13 */ + @Override public final boolean isNullSafe() { return this.nullSafe; } diff --git a/spring-expression/src/main/java/org/springframework/expression/spel/ast/PropertyOrFieldReference.java b/spring-expression/src/main/java/org/springframework/expression/spel/ast/PropertyOrFieldReference.java index a033f6c14b49..bb2e17197376 100644 --- a/spring-expression/src/main/java/org/springframework/expression/spel/ast/PropertyOrFieldReference.java +++ b/spring-expression/src/main/java/org/springframework/expression/spel/ast/PropertyOrFieldReference.java @@ -76,6 +76,7 @@ public PropertyOrFieldReference(boolean nullSafe, String propertyOrFieldName, in /** * Does this node represent a null-safe property or field reference? */ + @Override public boolean isNullSafe() { return this.nullSafe; } diff --git a/spring-expression/src/main/java/org/springframework/expression/spel/ast/SpelNodeImpl.java b/spring-expression/src/main/java/org/springframework/expression/spel/ast/SpelNodeImpl.java index f6cbaa6c97c7..3fb9208bc1b8 100644 --- a/spring-expression/src/main/java/org/springframework/expression/spel/ast/SpelNodeImpl.java +++ b/spring-expression/src/main/java/org/springframework/expression/spel/ast/SpelNodeImpl.java @@ -181,6 +181,16 @@ public int getEndPosition() { return this.endPos; } + /** + * Determine if this node is the target of a null-safe navigation operation. + *

The default implementation returns {@code false}. + * @return {@code true} if this node is the target of a null-safe operation + * @since 6.1.6 + */ + public boolean isNullSafe() { + return false; + } + /** * 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