[
https://issues.apache.org/jira/browse/FELIX-6137?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16853037#comment-16853037
]
David Bosschaert edited comment on FELIX-6137 at 5/31/19 1:51 PM:
------------------------------------------------------------------
Hi [~marett], this is actually by design. You can convert a map to an interface
or annotation without having to specify all the values available as methods in
those. However, if you invoke a method on the interface or annotation for which
no value is specified in the original map or a default is otherwise provided,
the converter throws an exception. This behaviour is specified in the OSGi
converter spec
([https://osgi.org/specification/osgi.enterprise/7.0.0/util.converter.html#util.converter-maps)]
section 707.4.4.4.5 Annotation states: "If no default is specified a
ConversionException is thrown."
However, since returning {{null}} for undefined values is a pretty common
scenario, you can quite easily achieve this by slightly customizing your
converter using an Error Handler. This is described in section 707.7
([https://osgi.org/specification/osgi.enterprise/7.0.0/util.converter.html#d0e107836)]
of the converter spec.
So to apply this to your test case, instead of
{code:java}
@Test
public void testDictionaryToAnnotationWithoutDefault() {
Dictionary<String, Object> dict = new TestDictionary<>();
TestAnnotation ta = converter.convert(dict).to(TestAnnotation.class);
assertEquals(null, ta.noDefault());
}
{code}
You can change it to:
{code:java}
@Test
public void testDictionaryToAnnotationWithoutDefault() {
Converter nullDefaultConverter = converter.newConverterBuilder().
errorHandler((o,t) -> null).build();
Dictionary<String, Object> dict = new TestDictionary<>();
TestAnnotation ta = nullDefaultConverter.convert(dict).
to(TestAnnotation.class);
assertEquals(null, ta.noDefault());
}
{code}
Note the error handler lambda, which will return null instead of throwing a
conversion exception. It will provide the behaviour you are looking for I think.
was (Author: bosschaert):
Hi [~marett], this is actually by design. You can convert a map to an interface
or annotation without having to specify all the values available as methods in
those. However, if you invoke a method on the interface or annotation for which
no value is specified in the original map or a default is otherwise provided,
the converter throws an exception. This behaviour is specified in the OSGi
converter spec
([https://osgi.org/specification/osgi.enterprise/7.0.0/util.converter.html#util.converter-maps)]
section 707.4.4.4.5 Annotation states: "If no default is specified a
ConversionException is thrown."
However, since returning {{null}} for undefined values is a pretty common
scenario, you can quite easily achieve this by slightly customizing your
converter using an Error Handler. This is described in section 707.7
([https://osgi.org/specification/osgi.enterprise/7.0.0/util.converter.html#d0e107836)]
of the converter spec.
So to apply this to your test case, instead of
{code:java}
@Test
public void testDictionaryToAnnotationWithoutDefault() {
Dictionary<String, Object> dict = new TestDictionary<>();
TestAnnotation ta = converter.convert(dict).to(TestAnnotation.class);
assertEquals(null, ta.noDefault());
}
{code}
You can change it to:
{code:java}
@Test
public void testDictionaryToAnnotationWithoutDefault() {
Converter nullDefaultConverter = converter.newConverterBuilder().
errorHandler((o,t) -> null).build();
Dictionary<String, Object> dict = new TestDictionary<>();
TestAnnotation ta =
nullDefaultConverter.convert(dict).to(TestAnnotation.class);
assertEquals(null, ta.noDefault());
}
{code}
Note the error handler lambda, which will return null instead of throwing a
conversion exception. It will provide the behaviour you are looking for I think.
> Converting an default-less annotation property throws instead of returning
> null
> -------------------------------------------------------------------------------
>
> Key: FELIX-6137
> URL: https://issues.apache.org/jira/browse/FELIX-6137
> Project: Felix
> Issue Type: Bug
> Components: Converter
> Affects Versions: converter-1.0.8
> Reporter: Timothee Maret
> Assignee: David Bosschaert
> Priority: Major
>
> Converting a dictionary to an annotation that does not define a default value
> property throws a {{org.osgi.util.converter.ConversionException}} like the
> one below instead of returning {{null}}.
> {code}
> org.osgi.util.converter.ConversionException: No value for property: noDefault
> at
> org.osgi.util.converter.ConvertingImpl$4.invoke(ConvertingImpl.java:806)
> at org.osgi.util.converter.$Proxy9.noDefault(Unknown Source)
> at
> org.osgi.util.converter.ConverterMapTest.testDictionaryToAnnotationWithoutDefault(ConverterMapTest.java:520)
> 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.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
> at
> org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
> 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)
> {code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
