opa.DatabaseResourceBundle.java Source code

Introduction

Here is the source code for opa.DatabaseResourceBundle.java

Source

/* 
 * Copyright (C) 2009 Chris Longtin
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * 
 * This class will retrieve messages from the database instead of a message
 * resource file.
 */
package opa;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.ResourceBundle;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * @author Chris Longtin
 * @email chris.longtin@gmail.com
 * 
 */
public class DatabaseResourceBundle extends ResourceBundle {

    private final static Log log = LogFactory.getLog(DatabaseResourceBundle.class);

    Integer langId;
    String jndiJdbc;

    private Connection connection;

    public DatabaseResourceBundle(String jndiJdbc, Integer langId) {
        setLangId(langId);
        setJndiJdbc(jndiJdbc);
    }

    public void init() {
        releaseConnection(connection);
        connection = createConnection();
    }

    public void destroy() {
        releaseConnection(connection);
    }

    @Override
    public Enumeration<String> getKeys() {
        String sql = "SELECT phrase FROM phrases WHERE lang_id = " + langId;

        ArrayList<String> values = new ArrayList<String>();

        try {
            ResultSet rs = getConnection().createStatement().executeQuery(sql);

            if (rs.next())
                values.add("phrase");

            rs.close();

        } catch (Exception e) {
            log.error(e, e);
        }

        return Collections.enumeration(values);
    }

    @Override
    protected Object handleGetObject(String key) {
        String sql = "SELECT phrase FROM phrases WHERE phrase_id = " + key + " AND lang_id = " + langId;

        String value = null;

        try {
            ResultSet rs = getConnection().createStatement().executeQuery(sql);

            if (rs.next())
                value = rs.getString("phrase");

            rs.close();

        } catch (Exception e) {
            log.error(e, e);
        }

        return value;
    }

    /**
     * Return a database connection. null if one cannot be achieved.
     * 
     * @return
     */
    private Connection createConnection() {
        try {
            Context ctx = new InitialContext();
            DataSource ds = (DataSource) ctx.lookup("java:comp/env/" + jndiJdbc);
            return ds.getConnection();
        } catch (NamingException e) {
            log.error("java:comp/env/" + jndiJdbc + " not found!", e);
        } catch (SQLException e) {
            log.error(e, e);
        }

        return null;
    }

    /**
     * Try and release the given database connection.
     * 
     * @param conn
     *            true if successful or if it was already closed/null, false if
     *            the close operation failed.
     * @return
     */
    private boolean releaseConnection(Connection conn) {
        try {
            if (conn != null && !conn.isClosed()) {
                conn.close();
            }

            return true;
        } catch (SQLException e) {
            return false;
        }
    }

    public Integer getLangId() {
        return langId;
    }

    public void setLangId(Integer langId) {
        this.langId = langId;
    }

    public String getJndiJdbc() {
        return jndiJdbc;
    }

    public void setJndiJdbc(String jndiJdbc) {
        this.jndiJdbc = jndiJdbc;
    }

    public Connection getConnection() {
        return connection;
    }

    public void setConnection(Connection connection) {
        this.connection = connection;
    }
}