Very short answer: you are looking for the resource in the scope of a classloader's class instead of your target class. This should work:

File file = new File(getClass().getResource("jsonschema.json").getFile());
JsonNode mySchema = JsonLoader.fromFile(file);

Also, that might be helpful reading:

• What is the difference between Class.getResource() and ClassLoader.getResource()?
• Strange behavior of Class.getResource() and ClassLoader.getResource() in executable jar
• Loading resources using getClass().getResource()

P.S. there is a case when a project compiled on one machine and after that launched on another or inside Docker. In such a scenario path to your resource folder would be invalid and you would need to get it in runtime:

ClassPathResource res = new ClassPathResource("jsonschema.json");    
File file = new File(res.getPath());
JsonNode mySchema = JsonLoader.fromFile(file);

Update from 2020

On top of that if you want to read resource file as a String, for example in your tests, you can use these static utils methods:

public static String getResourceFileAsString(String fileName) {
    InputStream is = getResourceFileAsInputStream(fileName);
    if (is != null) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        return (String)reader.lines().collect(Collectors.joining(System.lineSeparator()));
    } else {
        throw new RuntimeException("resource not found");
    }
}

public static InputStream getResourceFileAsInputStream(String fileName) {
    ClassLoader classLoader = {CurrentClass}.class.getClassLoader();
    return classLoader.getResourceAsStream(fileName);
}

Example of usage:

String soapXML = getResourceFileAsString("some_folder_in_resources/SOPA_request.xml");

Since OP is injecting Only the fileName through spring, still want to create the File Object through code , You should Use ClassLoadeer to read the file

Try this

InputStream is =  HandleData.class.getClassLoader().getResourceAsStream(getFile()));

Edit

Heres the remainder of code , to read the file

BufferedInputStream bf = new BufferedInputStream(is);
DataInputStream dis = new DataInputStream(bf);

while (dis.available() != 0) {
    System.out.println(dis.readLine());
}

Edit 2

Since you want it as File Object, to get hold of the FileInputStream

try this

 FileInputStream fisTargetFile = new FileInputStream(new File(HandleData.class.getClassLoader().getResource(getFile()).getFile()));

You can't access a @Value resource unless it is a property defined. It should be this way.

@Value("${stateJsonPath}")
Resource stateFile;

If you have to get the resource from a hardcoded path then use this way:

import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
//...
Resource stateFile = new ClassPathResource("state.json");