NPE when <annotation> is not provided in XSD

[Nogyara]

First, an extract of stacktrace:

...
Caused by: java.lang.NullPointerException
    at info.hubbitus.XJCPluginDescriptionAnnotation.fieldGetDescriptionAnnotation (XJCPluginDescriptionAnnotation.java:199)
    at info.hubbitus.XJCPluginDescriptionAnnotation.access$200 (XJCPluginDescriptionAnnotation.java:80)
    at info.hubbitus.XJCPluginDescriptionAnnotation$2.<init> (XJCPluginDescriptionAnnotation.java:116)
    at info.hubbitus.XJCPluginDescriptionAnnotation.lambda$null$2 (XJCPluginDescriptionAnnotation.java:116)

Now, the problem happens, when in an XSD, there's no element (which is perfectly valid). This problem has actually two instances:

• info.hubbitus.XJCPluginDescriptionAnnotation#fieldGetDescriptionAnnotation
• info.hubbitus.XJCPluginDescriptionAnnotation#classInfoGetDescriptionAnnotation

I suggest to rewrite these two methods as follows, which fixes both instances of the problem:

	private static String classInfoGetDescriptionAnnotation(CClassInfo classInfo){
		XSAnnotation annotation = classInfo.getSchemaComponent().getAnnotation();
		return resolveDescription(annotation);
	}

	private static String fieldGetDescriptionAnnotation(CPropertyInfo propertyInfo){
		XSAnnotation annotation = resolveXSAnnotation(propertyInfo.getSchemaComponent());
		return resolveDescription(annotation);
	}

	private static String resolveDescription(XSAnnotation annotation) {
		String description = "";
		if (annotation != null && annotation.getAnnotation() != null) {
			description = ((BindInfo) annotation.getAnnotation()).getDocumentation();
			if (description == null) {
				description = "";
			}
		}
		return description.trim();
	}

	private static XSAnnotation resolveXSAnnotation(XSComponent schemaComponent) {
		XSAnnotation annotation;
		//<xs:complexType name="TDocumentRefer">
		//		<xs:attribute name="documentID" use="required">
		//			<xs:annotation>
		//				<xs:documentation>Идентификатор документа</xs:documentation>
		if (schemaComponent instanceof AttributeUseImpl) {
			annotation = ((AttributeUseImpl) schemaComponent).getDecl().getAnnotation();
		}
		// <xs:complexType name="TBasicInterdepStatement">
		//		<xs:element name="header" type="stCom:TInterdepStatementHeader" minOccurs="0">
		//				<xs:annotation>
		//					<xs:documentation>Заголовок заявления</xs:documentation>
		else if (schemaComponent instanceof ParticleImpl) {
			annotation = (((ParticleImpl) schemaComponent).getTerm()).getAnnotation();
		} else {
			throw new UnsupportedOperationException("Unsupported schema component class: " + schemaComponent.getClass().getName());
		}
		return annotation;
	}

[Hubbitus]

Thank you for the bugreport. Could you please provide small reproduce for problem? XSD and may be minimal gradle project?

[Nogyara]

Sorry, I'm not on that project (nor in that company) any longer but I believe I provided very good description and suggested fix - no more I can do.

However, If you check info.hubbitus.XJCPluginDescriptionAnnotation.fieldGetDescriptionAnnotation (XJCPluginDescriptionAnnotation.java:199) line for the version of your plugin which was available at the time of my bug report, you should be able to find out the cause by yourself.

[Hubbitus]

@Nogyara, I've extend test by case of element without annotation. And all work well.

Could you please provide your XSD on which you see NPE?

[Nogyara]

Well, like I wrote, I§m not on the project any longer. But if you check the version of file which existed by the time I reported the issue (https://github.com/Hubbitus/xjc-documentation-annotation-plugin/blob/904c002402a37dad228e55114a9b8aae45574453/src/main/java/info/hubbitus/XJCPluginDescriptionAnnotation.java), you'll see that the only way how you'd get NPE on line 199 is if description was null.

Because description is declared as empty string on line 181, it means that one of the if blocks had to change its value to null. Which means, that in case that in an XSD, if you have e.g.

<xs:element name="whatever>
<xs:annotation />
</xs:element>

i.e. with no element inside, this NPE would occur.
This is my current guess from reading the source code, don't have clone of your repo anymore, but I'm quite sure that's the case when it blows. Also, don't forget there are two instances of this bugas I meantioned in the actual bug report.

Good luck