如何从注释处理器创建文件名中带有空格的资源

Question

When generating resource file on compile time using javax.annotation.processing.Processor , not able to create files with spaces in the file name.

Simplified code to reproduce the problem:

public class SampleAnnotationProcessor extends AbstractProcessor {

@Override
public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment env) {
    for (Element element : env.getElementsAnnotatedWith(SampleAnnotation.class)) {
        FileObject resource = processingEnv.getFiler()
                .createResource(StandardLocation.CLASS_OUTPUT, "configs.generated", "file name with spaces.xml", element);
        // ...
    }

    return true;
}

}

On jdk1.8.0_212.jdk it fails with:

java.lang.IllegalArgumentException: Invalid relative name: file name with spaces.xml

As such resource would be packaged just fine into jar if present in src/resources , I assume the same should be possible when auto-generated as well.

Is there a way to escape the spaces, or do something else to generate such files on compile time?

Answer 1

As a brute force approach, renaming the resulting file does the trick:

String nameWithoutSpaces = desiredFilename.replace(" ", "-");
FileObject resource = processingEnv.getFiler()
                .createResource(StandardLocation.CLASS_OUTPUT, "configs.generated", nameWithoutSpaces, element);

Path generatedResourcePath = Paths.get(resource.toUri());
Path desiredPath = generatedResourcePath.getParent().resolve(desiredFilename);
Files.move(generatedResourcePath, desiredPath, StandardCopyOption.REPLACE_EXISTING);

Still looking for more conventional approach. Reference to a bug/ticket or specification note explaining why a resource can't have spaces work too.