[BVAL-129] JDK8 - Annotations on synthetic bridge methods break bval

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.5, 1.1.0
• Component/s: jsr303

Environment

JDK8

• Assignee: Unassigned
• Reporter: Liam Miller-Cushon
• Created: 04/May/14 19:05
• Updated: 29/Sep/16 23:08
• Resolved: 04/May/14 20:03

Description

As of jdk8, the java compiler now copies annotations onto synthetic bridge methods. See https://bugs.openjdk.java.net/browse/JDK-6695379 for more information about the change. When javac creates synthetic copies of methods the method signatures are erased. This violates assumptions made by bval.

Consider the following example:

===
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy =

{ MyValidator.class }

)
public @interface SomeAnnotation

{ … }

public static class MyValidator implements ConstraintValidator<SomeAnnotation, String> { … }

public interface Id<T> {
T getId();
}

public static class ObjectToValidate implements Id<String> {
@SomeAnnotation
public String getId()

{ return null; }

}
===

The compiler creates a bridge method for ObjectToValidate.getId with the erased return type of Object. Prior to jdk8 this method had no annotations and was ignored by bval, but with the change in jdk8 the validation fails:

$ export JAVA_HOME=/Library/Java/JavaVirtualMachinesLibrary/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home/ && mvn clean package exec:java -Dexec.mainClass="Test"
…
SUCCESS

$ export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/Home/ && mvn clean package exec:java -Dexec.mainClass="Test"
...
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:293)
at java.lang.Thread.run(Thread.java:744)
Caused by: javax.validation.UnexpectedTypeException: No validator could be found for type java.lang.Object. See: @SomeAnnotation at public java.lang.Object Test$ObjectToValidate.getId()
at org.apache.bval.jsr303.AnnotationProcessor.checkOneType(AnnotationProcessor.java:326)
at org.apache.bval.jsr303.AnnotationProcessor.getConstraintValidator(AnnotationProcessor.java:301)
at org.apache.bval.jsr303.AnnotationProcessor.applyConstraint(AnnotationProcessor.java:241)
at org.apache.bval.jsr303.AnnotationProcessor.processAnnotation(AnnotationProcessor.java:149)
at org.apache.bval.jsr303.AnnotationProcessor.processAnnotations(AnnotationProcessor.java:90)
at org.apache.bval.jsr303.Jsr303MetaBeanFactory.processClass(Jsr303MetaBeanFactory.java:156)
at org.apache.bval.jsr303.Jsr303MetaBeanFactory.buildMetaBean(Jsr303MetaBeanFactory.java:95)
at org.apache.bval.MetaBeanBuilder.buildForClass(MetaBeanBuilder.java:131)
at org.apache.bval.MetaBeanManager.findForClass(MetaBeanManager.java:102)
at org.apache.bval.jsr303.ClassValidator.validate(ClassValidator.java:140)
at Test.main(Test.java:33)
... 6 more

Proposed solution:

To preserve the behaviour bval had pre-jdk8, it can simply ignore the synthetic bridge methods. The following patch would accomplish this:

===
— src/main/java/org/apache/bval/jsr303/Jsr303MetaBeanFactory.java
+++ src/main/java/org/apache/bval/jsr303/Jsr303MetaBeanFactory.java
@@ -139,6 +139,9 @@
}
final Method[] methods = doPrivileged(SecureActions.getDeclaredMethods(beanClass));
for (Method method : methods) {
+ if (method.isSynthetic() || method.isBridge())

{ + continue; + }

String propName = null;
if (method.getParameterTypes().length == 0) {
propName = MethodAccess.getPropertyName(method);
===