This commit introduces a new CompilableIndexAccessor SPI for the Spring
Expression Language (SpEL) which allows an IndexAccessor to support
compilation to bytecode for operations that read an index.
This analogous to the CompilablePropertyAccessor SPI.
This commit also includes a prototype for a general purpose
ReflectiveIndexAccessor in the tests.
Closes gh-32613
In order to make SpelNode compilation aware, this method moves the
declaration of isCompilable() and generateCode(...) from SpelNodeImpl
to SpelNode.
Closes gh-32707
Prior to this commit, the Spring Expression Language (SpEL) failed to
compile an expression that indexed into any array or list using an
Integer.
This commit adds support for compilation of such expressions by
ensuring that an Integer is unboxed into an int in the compiled
bytecode.
Closes gh-32694
Prior to this commit, the read() method in the IndexAccessor SPI
declared a return type of ValueRef which introduced a package cycle.
This commit addresses this by aligning with the PropertyAccess SPI and
returning TypedValue from IndexAccessor's read() method. This commit
also reworks the internals of Indexer based on a new, local
IndexAccessorValueRef implementation.
See gh-26409
See gh-26478
Prior to this commit, SpEL's CompoundExpression omitted the null-safe
syntax in AST string representations of indexing operations.
To address this, this commit implements isNullSafe() in Indexer.
See gh-29847
Prior to this commit, SpEL's CompoundExpression omitted the null-safe
syntax in AST string representations of the selection and projection
operators.
To address this, this commit implements isNullSafe() in Projection and
Selection.
Closes gh-32515
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
Prior to this commit, the SpEL compiler generated classes in a package
named "spel" with names following the pattern "Ex#", where # was an
index starting with 2.
This resulted in class names such as:
- spel.Ex2
- spel.Ex3
This commit improves the names of classes created by the SpEL compiler
by generating classes in a package named
"org.springframework.expression.spel.generated" with names following
the pattern "CompiledExpression#####", where ##### is a 0-padded
counter starting with 00001.
This results in class names such as:
- org.springframework.expression.spel.generated.CompiledExpression00001
- org.springframework.expression.spel.generated.CompiledExpression00002
This commit also moves the saveGeneratedClassFile() method from
SpelCompilationCoverageTests to SpelCompiler and enhances it to:
- Save classes in a "build/generated-classes" directory.
- Convert package names to directories.
- Create missing parent directories.
- Use logging instead of System.out.println().
Running a test with saveGeneratedClassFile() enabled now logs something
similar to the following.
DEBUG o.s.e.s.s.SpelCompiler - Saving compiled SpEL expression [(#root.empty ? 0 : #root.size)] to [/Users/<username>/spring-framework/spring-expression/build/generated-classes/org/springframework/expression/spel/generated/CompiledExpression00001.class]
Closes gh-32497
Sam Brannen
ljmn3211
Sébastien Deleuze
Grigory Stepanov