hellomanager.java

来自「Java的面向对象数据库系统的源代码」· Java 代码 · 共 42 行

package cli;

import db.Hello;
import db.HelloImpl;
import org.ozoneDB.ExternalDatabase;
import org.ozoneDB.OzoneInterface;
import web.HelloServlet;

public class HelloManager {

    private static Hello hello;
    private static ExternalDatabase db;

    public static void main(String[] args) {
        try {
            buildObject();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**  makes sure there is a Hello object in Ozone
     *  we keep it extremely simple to show the idea, things could be
     *  easily parameterized.
     */
    private static void buildObject() throws Exception {
        System.out.println("Trying to connect to ozone...");
        db = ExternalDatabase.openDatabase("ozonedb:remote://localhost:3333");
        System.out.println("....Connected to ozone");
        db.reloadClasses();
        System.out.println("....Classes reloaded");
        hello = (Hello) db.objectForName(HelloServlet.OBJ_NAME);
        if (hello == null) {
            System.out.println("Storing new Hello object");
            hello = (Hello) db.createObject(HelloImpl.class.getName(), OzoneInterface.Public, HelloServlet.OBJ_NAME);
        } else {
            System.out.println("Found existing Hello object");
        }
        System.out.println("db.Hello has the following greeting: " + hello.getGreeting());
        db.close();
    }
}