How to inject java.nio.file.Path dependency using #ConfigurationProperties - spring

Question

I'm using Spring Boot and have the following Component class:
#Component
#ConfigurationProperties(prefix="file")
public class FileManager {
private Path localDirectory;
public void setLocalDirectory(File localDirectory) {
this.localDirectory = localDirectory.toPath();
}
...
}
And the following yaml properties file:
file:
localDirectory: /var/data/test
I would like to remove the reference of java.io.File (of setLocalDirectory) by replacing with java.nio.file.Path. However, I receive a binding error when I do this. Is there way to bind the property to a Path (e.g. by using annotations)?

Answer 1

To add to jst's answer, the Spring Boot annotation #ConfigurationPropertiesBinding can be used for Spring Boot to recognize the converter for property binding, as mentioned in the documentation under Properties Conversion:
#Component
#ConfigurationPropertiesBinding
public class StringToPathConverter implements Converter<String, Path> {
#Override
public Path convert(String pathAsString) {
return Paths.get(pathAsString);
}
}

Answer 2

I don't know if there is a way with annotations, but you could add a Converter to your app. Marking it as a #Component with #ComponentScan enabled works, but you may have to play around with getting it properly registered with the ConversionService otherwise.
#Component
public class PathConverter implements Converter<String,Path>{
#Override
public Path convert(String path) {
return Paths.get(path);
}
When Spring sees you want a Path but it has a String (from your application.properties), it will lookup in its registry and find it knows how to do it.

Answer 3

I took up james idea and defined the converter within the spring boot configuration:
#SpringBootConfiguration
public class Configuration {
public class PathConverter implements Converter<String, Path> {
#Override
public Path convert(String path) {
return Paths.get(path);
}
}
#Bean
#ConfigurationPropertiesBinding
public PathConverter getStringToPathConverter() {
return new PathConverter();
}
}