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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)