java.io.FileNotFoundException:classpathresourceeventhoughfileexistsinsrc/main/resources

I have my XML file under the src/main/resources directory. My spring code looks like

import java.io.IOException;
import java.util.concurrent.atomic.AtomicLong;

import com.google.common.base.Charsets;
import com.google.common.io.Files;
import org.springframework.core.io.ClassPathResource;
import org.springframework.integration.xml.transformer.XsltPayloadTransformer;
import org.springframework.messaging.Message;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class BdeApplicationController {

    @GetMapping("/ping")
    @ResponseBody
    public String ping(@RequestParam(name="name", required=false, defaultValue="Stranger") String name) {
        return myFlow();
    }

    private String myFlow() {
        XsltPayloadTransformer transformer = getXsltTransformer();
        return transformer.transform(buildMessage(getXMLFileString())).toString();
    }

    private String getXMLFileString() {
        try {
            return Files.toString(new ClassPathResource("XML1.xml").getFile(), Charsets.UTF_8);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "";
    }

    private XsltPayloadTransformer getXsltTransformer() {
        return new XsltPayloadTransformer(new ClassPathResource("XSLT1.xsl"));
    }

    protected Message buildMessage(Object payload) {
        return MessageBuilder.withPayload(payload).build();
    }
}

On running this code I get the following exception: -

java.io.FileNotFoundException: class path resource [XML1.xml] cannot be resolved to absolute file path because it does not reside in the file system: jar:file:/Users/user/Documents/project/target/bde-0.0.1-SNAPSHOT.jar!/BOOT-INF/classes!/XML1.xml

Can you please suggest how can I fix this?

When you use resource.getFile() you look for the file in the file system, thats why it does't work when you runnit as a jar.

Try with a InputStream

String data = "";
ClassPathResource resource = new ClassPathResource("/XML1.xml");
try {
    byte[] dataArr = FileCopyUtils.copyToByteArray(resource.getInputStream());
    data = new String(dataArr, StandardCharsets.UTF_8);
} catch (IOException e) {
    // do whatever
}