fr.calamus.common.db.core.DbCentralFactory.java Source code

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Here is the source code for fr.calamus.common.db.core.DbCentralFactory.java

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package fr.calamus.common.db.core;

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Timer;
import java.util.TimerTask;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 *
 * @author haerwynn
 */
public abstract class DbCentralFactory<T extends DbCentralFactory> implements IDbFactory<T> {

    protected static final Map<String, DbCentralFactory<?>> instances = Collections
            .synchronizedMap(new HashMap<String, DbCentralFactory<?>>());
    private static final Log log = LogFactory.getLog(DbCentralFactory.class);
    private static SimpleDateFormat frDateFormatter;
    private static SimpleDateFormat usDateFormatter;
    private static boolean instancesObserverIsLaunched = false;

    public static <T extends DbCentralFactory> T init(Class<T> factoryClass) {
        T db = null;
        try {
            db = (T) factoryClass.newInstance();
            instances.put(null, db);
        } catch (InstantiationException ex) {
            ex.printStackTrace();
        } catch (IllegalAccessException ex) {
            ex.printStackTrace();
        }
        launchInstancesObserver();
        return db;
    }

    public static SimpleDateFormat getFrDateFormatter() {
        if (frDateFormatter == null) {
            frDateFormatter = new SimpleDateFormat("dd/MM/yyyy");
        }
        return frDateFormatter;
    }

    public boolean isConnectionOk() {
        return dbAccess() != null && !dbAccess().isClosed();
    }

    public static SimpleDateFormat getUsDateFormatter() {
        if (usDateFormatter == null) {
            usDateFormatter = new SimpleDateFormat("yyyy-MM-dd");
        }
        return usDateFormatter;
    }

    public static DbCentralFactory getInstance(String id) {
        if (instances.get(null) == null) {
            throw new RuntimeException("Not inited !");
        }
        if (instances.get(id) == null || instances.get(id).isClosed()) {
            if (instances.get(id) == null) {
                log.debug("creating new instance : " + id);
                instances.put(id, newInstance());
            } else {
                log.debug("reconnecting instance : " + id);
                DbCentralFactory db = instances.get(id);
                db.reconnect();
            }
            log.debug(" " + instances.size() + " instances");
        }
        return (DbCentralFactory) instances.get(id);
    }

    public boolean isClosed() {
        return dbAccess().isClosed();
    }

    public static DbCentralFactory newInstance() {
        //return (T) ((T)getInstance()).getNewInstance();
        DbCentralFactory t = getInstance();
        return (DbCentralFactory) t.getNewInstance();
    }

    public static DbCentralFactory getInstance() {
        return getInstance(null);
    }

    public void reconnect() {
        dbAccess().reconnect();
    }

    protected abstract long cnxTimeOut();

    protected static void launchInstancesObserver() {
        if (!instancesObserverIsLaunched) {
            Timer timer = new Timer("DbFactory-instancesRemover", true);
            TimerTask task = new TimerTask() {
                @Override
                public void run() {
                    synchronized (instances) {
                        long now = System.currentTimeMillis();
                        List<String> toRemove = new ArrayList<>();
                        for (String id : instances.keySet()) {
                            DbCentralFactory db = instances.get(id);
                            if (id != null && (db == null || now > db.lastUsedTime() + db.cnxTimeOut())) {
                                toRemove.add(id);
                            }
                        }
                        for (String id : toRemove) {
                            DbCentralFactory db = instances.get(id);
                            if (db != null) {
                                db.close();
                            }
                            instances.remove(id);
                        }
                        if (toRemove.size() > 0) {
                            log.debug("removed " + toRemove.size() + " instance(s); remaining " + instances.size());
                        }
                    }
                }
            };
            timer.schedule(task, 30000, 10000);
            instancesObserverIsLaunched = true;
        }
    }

    public long lastUsedTime() {
        return dbAccess().lastUsedTime();
    }

    public void close() {
        dbAccess().close();
    }

}