Spring - inject contents of file from classpath into annotated member

Question

Is it possible to inject the contents of a file on classpath to a member variable upon construction of the corresponding class?

@Component
public class MyClass {
    @Value("classpath:my_file.txt")
    private String myFile;
}

Answer 1

There is the annotation @Value, but it will inject a Resource, not its contents.

But once you have the resource, you can easily read its contents with class StreamUtils as below:

import java.io.InputStream;
import java.nio.charset.StandardCharsets;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.Resource;
import org.springframework.util.StreamUtils;

@Value("classpath:/file.txt")
public void setFile(Resource myRes) throws IOException {
    try (InputStream is = myRes.getInputStream()) {
        // Content of the file as a String
        String contents = StreamUtils.copyToString(is, StandardCharsets.UTF_8);
    }
}

Answer 2

Sure

import org.springframework.core.io.Resource;

@Value("classpath:my_file.txt")
private Resource myFile;