org.springframework.core.TypeDescriptor.getAnnotations() should return the method annotation when it wraps the return parameter of the Method [SPR-6979]

[spring-projects-issues]

Thomas Scheiblauer opened SPR-6979 and commented

If a TypeDescriptor is created from the return parameter of a method e.g.
TypeDescriptor typeDescr = new TypeDescriptor(new MethodParameter(method, -1))
where -1 denotes the return parameter then
typeDescr.getAnnotations() should return the annotations applied to the method.
3.0.1 crashes with an array index out of bounds exception because the called MethodParameter.getParameterAnnotations() tries to index an empty Annotations Array with -1,
the current 3.0.2 nightly fixes at least the exception by returning an empty Array in this case.
Since e.g. org.springframework.core.convert.ConversionService or org.codehaus.jackson.map.JsonSerializer<Object> need the TypeDescriptor for type conversions either MethodParameter.getParameterAnnotations() or TypeDescriptor.getAnnotations() should return the method annotations in case of a wrapped return parameter.
I bumped into this problem while trying to modify the getTypeDescriptorForSerializer method in this mvc ajax example:
https://src.springframework.org/svn/spring-samples/mvc-ajax/trunk/src/main/java/org/springframework/samples/mvc/ajax/json/FormatAnnotationIntrospector.java
according to the TODO note.

---

Affects: 3.0.1, 3.0.2

Attachments:

• FormatAnnotationIntrospector.java (1.77 kB)
• typedescriptor.diff (713 bytes)

Referenced from: commits 65b0a8f

[spring-projects-issues]

Thomas Scheiblauer commented

the topic should read: 'org.springframework.core.convert.TypeDescriptor.getAnnotations() ...'
I patched TypeDescriptor.java to work as described above and modified the mentioned example code as proposed in it's TODO comment and it worked as expected. I will attach the patches for examination.

[spring-projects-issues]

Thomas Scheiblauer commented

patch for org/springframework/core/convert/TypeDescriptor.java

[spring-projects-issues]

Thomas Scheiblauer commented

This is my improved Version of FormatAnnotationIntrospector.java from the aforementioned example which handles setters and getters (as proposed in the TODO comments) instead of trying to find a possibly not existing private field that is named after the "property part" of the setter/getter methods

[spring-projects-issues]

Thomas Scheiblauer commented

Annotations for the serializer/deserializer converters get now annotated like this (tested and working after applying the typedescriptor.patch and using the improved FormatAnnotationIntrospector.java):
public class Test {
private Date date;

public Test() {
	date = new Date();
}

@DateTimeFormat(pattern = "yyyy-mm-dd hh:mm:ss")
public Date getDate() {
	return date;
}
public void setDate(@DateTimeFormat(pattern = "yyyy-mm-dd hh:mm:ss") Date date) {
	this.date = date;
}

}

[spring-projects-issues]

Juergen Hoeller commented

Addressed for 3.0.2, as part of a general overhaul of TypeDescriptor and PropertyTypeDescriptor. This will be available in tonight's 3.0.2 snapshot - feel free to give it an early try if you have the chance, and let me know whether it works for you.

Juergen

[spring-projects-issues]

Thomas Scheiblauer commented

I have just tested the current 3.0.2 snapshot (CI-632) and it works as expected :)

thx,
Tom