如何轻松地将基于XML的配置文件加载到Java类？

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class Configuration {
    private String host;
    private int port;
    private String username;
    private String password;

    @XmlElement
    public void setHost(String host) {
        this.host = host;
    }

    @XmlElement
    public void setPort(int port) {
        this.port = port;
    }

    @XmlElement
    public void setUsername(String username) {
        this.username = username;
    }

    @XmlElement
    public void setPassword(String password) {
        this.password = password;
    }

    public String getHost() {
        return host;
    }

    public int getPort() {
        return port;
    }

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
    }
}

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import java.io.File;

public class Main {
    public static void main(String[] args) {
        try {
            File file = new File("configuration.xml");
            JAXBContext jaxbContext = JAXBContext.newInstance(Configuration.class);

            Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
            Configuration configuration = (Configuration) jaxbUnmarshaller.unmarshal(file);
            jaxbUnmarshaller.unmarshal(file);
            System.out.println(configuration.getHost());
            System.out.println(configuration.getPort());
            System.out.println(configuration.getUsername());
            System.out.println(configuration.getPassword());
        } catch (JAXBException e) {
            e.printStackTrace();
        }
    }
}