From 83ca2c0cff43f28fc4ddba3f229636ea1f7e628e Mon Sep 17 00:00:00 2001 From: Sam Brannen <104798+sbrannen@users.noreply.github.com> Date: Wed, 10 Jul 2024 16:05:43 +0200 Subject: [PATCH] Support MethodHandle function invocation with varargs array in SpEL Prior to this commit, the Spring Expression Language (SpEL) could not invoke a varargs MethodHandle function with an array containing the variable arguments, although that is supported for a varargs Method function. Attempting to do so resulted in the array being supplied as a single argument to the MethodHandle. This commit addresses this by updating the executeFunctionViaMethodHandle(...) method in FunctionReference as follows when the user supplies the varargs already packaged in an array. - Creates a new array large enough to hold the non-varargs arguments and the unpackaged varargs arguments. - Adds the non-varargs arguments to the beginning of that array and adds the unpackaged varargs arguments to the end of that array. - Invokes the MethodHandle with the new arguments array. Closes gh-33191 --- .../spel/ast/FunctionReference.java | 27 ++++++++++++++++--- .../spel/VariableAndFunctionTests.java | 25 ++++++----------- 2 files changed, 31 insertions(+), 21 deletions(-) diff --git a/spring-expression/src/main/java/org/springframework/expression/spel/ast/FunctionReference.java b/spring-expression/src/main/java/org/springframework/expression/spel/ast/FunctionReference.java index 22206f4bcb..a798891f35 100644 --- a/spring-expression/src/main/java/org/springframework/expression/spel/ast/FunctionReference.java +++ b/spring-expression/src/main/java/org/springframework/expression/spel/ast/FunctionReference.java @@ -225,10 +225,29 @@ public class FunctionReference extends SpelNodeImpl { TypeConverter converter = state.getEvaluationContext().getTypeConverter(); ReflectionHelper.convertAllMethodHandleArguments(converter, functionArgs, methodHandle, varArgPosition); - if (isSuspectedVarargs && declaredParamCount == 1) { - // we only repack the varargs if it is the ONLY argument - functionArgs = ReflectionHelper.setupArgumentsForVarargsInvocation( - methodHandle.type().parameterArray(), functionArgs); + if (isSuspectedVarargs) { + if (declaredParamCount == 1) { + // We only repackage the varargs if it is the ONLY argument -- for example, + // when we are dealing with a bound MethodHandle. + functionArgs = ReflectionHelper.setupArgumentsForVarargsInvocation( + methodHandle.type().parameterArray(), functionArgs); + } + else if (spelParamCount == declaredParamCount) { + // If the varargs were supplied already packaged in an array, we have to create + // a new array, add the non-varargs arguments to the beginning of that array, + // and add the unpackaged varargs arguments to the end of that array. The reason + // is that MethodHandle.invokeWithArguments(Object...) does not expect varargs + // to be packaged in an array, in contrast to how method invocation works with + // reflection. + int actualVarargsIndex = functionArgs.length - 1; + if (actualVarargsIndex >= 0 && functionArgs[actualVarargsIndex].getClass().isArray()) { + Object[] argsToUnpack = (Object[]) functionArgs[actualVarargsIndex]; + Object[] newArgs = new Object[actualVarargsIndex + argsToUnpack.length]; + System.arraycopy(functionArgs, 0, newArgs, 0, actualVarargsIndex); + System.arraycopy(argsToUnpack, 0, newArgs, actualVarargsIndex, argsToUnpack.length); + functionArgs = newArgs; + } + } } try { diff --git a/spring-expression/src/test/java/org/springframework/expression/spel/VariableAndFunctionTests.java b/spring-expression/src/test/java/org/springframework/expression/spel/VariableAndFunctionTests.java index ea543ad26c..a725b95306 100644 --- a/spring-expression/src/test/java/org/springframework/expression/spel/VariableAndFunctionTests.java +++ b/spring-expression/src/test/java/org/springframework/expression/spel/VariableAndFunctionTests.java @@ -16,7 +16,6 @@ package org.springframework.expression.spel; -import org.junit.jupiter.api.Disabled; import org.junit.jupiter.api.Test; import org.springframework.expression.spel.standard.SpelExpressionParser; @@ -106,22 +105,6 @@ class VariableAndFunctionTests extends AbstractExpressionTests { evaluate("#varargsFunction2(9,'a',null,'b')", "9-[a, null, b]", String.class); } - @Disabled("Disabled until bugs are reported and fixed") - @Test - void functionWithVarargsViaMethodHandle_CurrentlyFailing() { - // Calling 'public static String formatObjectVarargs(String format, Object... args)' -> String.format(format, args) - - // No conversion necessary - evaluate("#formatObjectVarargs('x -> %s', new Object[]{''})", "x -> ", String.class); - evaluate("#formatObjectVarargs('x -> %s', new String[]{''})", "x -> ", String.class); - evaluate("#formatObjectVarargs('x -> %s', new Object[]{' '})", "x -> ", String.class); - evaluate("#formatObjectVarargs('x -> %s', new String[]{' '})", "x -> ", String.class); - evaluate("#formatObjectVarargs('x -> %s', new Object[]{'a'})", "x -> a", String.class); - evaluate("#formatObjectVarargs('x -> %s', new String[]{'a'})", "x -> a", String.class); - evaluate("#formatObjectVarargs('x -> %s %s %s', new Object[]{'a', 'b', 'c'})", "x -> a b c", String.class); - evaluate("#formatObjectVarargs('x -> %s %s %s', new String[]{'a', 'b', 'c'})", "x -> a b c", String.class); - } - @Test // gh-33013 void functionWithVarargsViaMethodHandle() { // Calling 'public static String formatObjectVarargs(String format, Object... args)' -> String.format(format, args) @@ -138,6 +121,14 @@ class VariableAndFunctionTests extends AbstractExpressionTests { evaluate("#formatObjectVarargs('x -> %s', ' ')", "x -> ", String.class); evaluate("#formatObjectVarargs('x -> %s', 'a')", "x -> a", String.class); evaluate("#formatObjectVarargs('x -> %s %s %s', 'a', 'b', 'c')", "x -> a b c", String.class); + evaluate("#formatObjectVarargs('x -> %s', new Object[]{''})", "x -> ", String.class); + evaluate("#formatObjectVarargs('x -> %s', new String[]{''})", "x -> ", String.class); + evaluate("#formatObjectVarargs('x -> %s', new Object[]{' '})", "x -> ", String.class); + evaluate("#formatObjectVarargs('x -> %s', new String[]{' '})", "x -> ", String.class); + evaluate("#formatObjectVarargs('x -> %s', new Object[]{'a'})", "x -> a", String.class); + evaluate("#formatObjectVarargs('x -> %s', new String[]{'a'})", "x -> a", String.class); + evaluate("#formatObjectVarargs('x -> %s %s %s', new Object[]{'a', 'b', 'c'})", "x -> a b c", String.class); + evaluate("#formatObjectVarargs('x -> %s %s %s', new String[]{'a', 'b', 'c'})", "x -> a b c", String.class); // Conversion necessary evaluate("#add('2', 5.0)", 7, Integer.class);