Bukkit Persistance reimplemented - no code changes required!

Comment.java

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

@Entity
@Table(name="comment")
public class Comment {
    @Id
    private int id;
    
    @ManyToOne
    private User user;
    
    private String contents;
    
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }
    public String getContents() {
        return contents;
    }
    public void setContents(String contents) {
        this.contents = contents;
    }
}

MyDatabasePlugin.java

package com.lennardf1989.mydatabaseplugin;

import java.util.ArrayList;
import java.util.List;

import org.bukkit.plugin.java.JavaPlugin;
import org.bukkit.util.config.Configuration;

import com.avaje.ebean.EbeanServer;
import com.lennardf1989.bukkitex.MyDatabase;

public class MyDatabasePlugin extends JavaPlugin {
    private static MyDatabasePlugin plugin;
    private MyDatabase database;
    
    public void onEnable() {
        try {
            //Store reference to this class
            plugin = this;
            
            //Load the configuration
            loadConfiguration();
            
            //Initialize the database
            initializeDatabase();

            //Plugin succesfully enabled
            System.out.print(String.format("[%s v%s] has been succesfully enabled!", getDescription().getName(), getDescription().getVersion()));
        }
        catch(Exception ex) {
            //Plugin failed to enable
            System.out.print(String.format("[%s v%s] could not be enabled!", getDescription().getName(), getDescription().getVersion()));

            //Print the stack trace of the actual cause
            Throwable t = ex;
            while(t != null) {
                if(t.getCause() == null) {
                    System.out.println(String.format("[%s v%s] exception:", getDescription().getName(), getDescription().getVersion()));
                    t.printStackTrace();
                }

                t = t.getCause();
            }
        }
    }

    public void onDisable() {
        System.out.println(String.format("%s version %s is disabled!", getDescription().getName(), getDescription().getVersion()));
    }

    public static MyDatabasePlugin getInstance() {
        return plugin;
    }

    private void loadConfiguration() {
        Configuration config = getConfiguration();
        
        config.setProperty("database.driver", config.getString("database.driver", "org.sqlite.JDBC"));
        config.setProperty("database.url", config.getString("database.url", "jdbc:sqlite:{DIR}{NAME}.db"));
        config.setProperty("database.username", config.getString("database.username", "root"));
        config.setProperty("database.password", config.getString("database.password", ""));
        config.setProperty("database.isolation", config.getString("database.isolation", "SERIALIZABLE"));
        config.setProperty("database.logging", config.getBoolean("database.logging", false));
        config.setProperty("database.rebuild", config.getBoolean("database.rebuild", true));
        
        config.save();
    }
    
    private void initializeDatabase() {
        Configuration config = getConfiguration();

        database = new MyDatabase(this) {
            protected java.util.List<Class<?>> getDatabaseClasses() {
                List<Class<?>> list = new ArrayList<Class<?>>();
                list.add(User.class);
                list.add(Comment.class);
        
                return list;
            };
        };
        
        database.initializeDatabase(
                config.getString("database.driver"),
                config.getString("database.url"),
                config.getString("database.username"),
                config.getString("database.password"),
                config.getString("database.isolation"),
                config.getBoolean("database.logging", false),
                config.getBoolean("database.rebuild", true)
            );
        
        config.setProperty("database.rebuild", false);
        config.save();
    }
    
    @Override
    public EbeanServer getDatabase() {
        return database.getDatabase();
    }
}

User.java

import java.util.ArrayList;
import java.util.List;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
@Table(name="user")
public class User {
    @Id
    private int id;
    
    private String name;
    
    @OneToMany(mappedBy="user", cascade=CascadeType.ALL)
    private List<Comment> comments = new ArrayList<Comment>();

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<Comment> getComments() {
        return comments;
    }

    public void setComments(List<Comment> comments) {
        this.comments = comments;
    }
}