Wrong byte code for compiled SpEL when JDK proxy method invocation is used [SPR-16191]

[spring-projects-issues]

Artem Bilan opened SPR-16191 and commented

The test-case to reproduce:

@Test
public void testCompiledSpELForProxy() {
	Foo foo = new FooImpl();

	foo = (Foo) new ProxyFactory(foo).getProxy();

	SpelExpressionParser expressionParser =
			new SpelExpressionParser(new SpelParserConfiguration(SpelCompilerMode.IMMEDIATE, null));

	Expression expression = expressionParser.parseExpression("#target.handle(#root)");

	StandardEvaluationContext evaluationContext = new StandardEvaluationContext();
	evaluationContext.setVariable("target", foo);

	String result = expression.getValue(evaluationContext, "foo", String.class);
	result = expression.getValue(evaluationContext, "foo", String.class);

	assertEquals("FOO", result);
}

public interface Foo {

	String handle(String payload);

}

public class FooImpl implements Foo {

	@Override
	public String handle(String payload) {
		return payload.toUpperCase();
	}

}

The exception looks like:

java.lang.IllegalStateException: Failed to instantiate CompiledExpression

    at org.springframework.expression.spel.standard.SpelCompiler.compile(SpelCompiler.java:110)
    at org.springframework.expression.spel.standard.SpelExpression.compileExpression(SpelExpression.java:517)
    at org.springframework.expression.spel.standard.SpelExpression.checkCompile(SpelExpression.java:487)
    at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:372)
    at org.springframework.integration.handler.MethodInvokingMessageProcessorTests.testCompiledSpELForProxy(MethodInvokingMessageProcessorTests.java:904)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.rules.ExpectedException$ExpectedExceptionStatement.evaluate(ExpectedException.java:239)
    at org.junit.rules.RunRules.evaluate(RunRules.java:20)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.VerifyError: (class: spel/Ex2, method: getValue signature: (Ljava/lang/Object;Lorg/springframework/expression/EvaluationContext;)Ljava/lang/Object;) Illegal type in constant pool
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671)
    at java.lang.Class.getConstructor0(Class.java:3075)
    at java.lang.Class.getDeclaredConstructor(Class.java:2178)
    at org.springframework.util.ReflectionUtils.accessibleConstructor(ReflectionUtils.java:503)
    at org.springframework.expression.spel.standard.SpelCompiler.compile(SpelCompiler.java:107)
    ... 28 more

The byte code for the compiled class:

����   1 !� �spel/Ex2� �� 6org/springframework/expression/spel/CompiledExpression� �� �<init>☃0001 �()V
getValue� X(Ljava/lang/Object;Lorg/springframework/expression/EvaluationContext;)Ljava/lang/Object;� 2org/springframework/expression/EvaluationException� �� �target
0org/springframework/expression/EvaluationContext� �� �lookupVariable� &(Ljava/lang/String;)Ljava/lang/Object; � �� � �� �com/sun/proxy/$Proxy5� �� Oorg/springframework/integration/handler/MethodInvokingMessageProcessorTests$Foo� �� �java/lang/String� �� �handle� &(Ljava/lang/String;)Ljava/lang/String; � �� � �� �Code
Exceptions � � �     � � � � � �   � � �   �*� ��
" � �   �,��� �� � �� �+� �� ��         � �   

With SF-5.0.1 it looks like (if that helps somehow..):

����   1 �� �spel/Ex2� �� 6org/springframework/expression/spel/CompiledExpression� �� �<init>� �()V
getValue� X(Ljava/lang/Object;Lorg/springframework/expression/EvaluationContext;)Ljava/lang/Object;� 2org/springframework/expression/EvaluationException� �� �target
0org/springframework/expression/EvaluationContext� �� �lookupVariable� &(Ljava/lang/String;)Ljava/lang/Object; � �� � �� �com/sun/proxy/$Proxy5� �� �java/lang/String� �� �handle� &(Ljava/lang/String;)Ljava/lang/String;
Code
Exceptions � � �     � � � � � �   � � �   ☃0005*� ��
,��� �� � �+� �� ��     �   � �   

It might be like a side-effect of the fix for the #20670 since we have the same problem with the 4.3.13 as well.

---

Affects: 4.3.13, 5.0.2

Issue Links:

• SpEL method invocation with varargs on proxy [SPR-16122] #20670 SpEL method invocation with varargs on proxy

Referenced from: commits c30145d, 6dc7346

Backported to: 4.3.13

[spring-projects-issues]

Juergen Hoeller commented

We're simply treating proxy-targeting expressions as non-compilable now. Fixed in master for 5.0.2.BUILD-SNAPSHOT; to be backported to 4.3.x ASAP.

[spring-projects-issues]

Artem Bilan commented

OK. Fine with me for now.

Just wonder if really someone will come back to us with the request to make them compilable one day :).

Thank you, Juergen!