net.mindengine.oculus.frontend.db.jdbc.MySimpleJdbcDaoSupport.java Source code

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Here is the source code for net.mindengine.oculus.frontend.db.jdbc.MySimpleJdbcDaoSupport.java

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/*******************************************************************************
* 2012 Ivan Shubin http://mindengine.net
* 
* This file is part of MindEngine.net Oculus Frontend.
* 
* 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 3 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 Oculus Frontend.  If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
package net.mindengine.oculus.frontend.db.jdbc;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
import org.springframework.jdbc.core.simple.SimpleJdbcDaoSupport;

/**
 * An entry point for the JDBC DAO support. This class should be a parent to all
 * DAO classes as it provides with all needed JDBC mapping activities.
 * 
 * @author Ivan Shubin
 * 
 */
public class MySimpleJdbcDaoSupport extends SimpleJdbcDaoSupport {
    protected BeanMappingFactory beanMappingFactory;
    protected Log logger = LogFactory.getLog(getClass());

    /**
     * Executes a sql query and converts the JDBC ResultSet to a list of java
     * bean objects.
     * 
     * @param sql
     *            The SQL command string
     * @param mapperClass
     *            The end-point class of a java bean
     * @param args
     *            An array of pairs of name and value for the
     *            {@link MapSqlParameterSource}
     * @return A list of mapped java bean objects.
     * @throws Exception
     */
    @SuppressWarnings("unchecked")
    public <T> List<T> query(String sql, Class<T> mapperClass, Object... args) throws Exception {
        logQuery(sql, args);
        if (args == null)
            return (List<T>) getSimpleJdbcTemplate().query(sql, beanMappingFactory.getBeanMapper(mapperClass));
        MapSqlParameterSource map = new MapSqlParameterSource();
        for (int i = 0; i < args.length; i += 2) {
            map.addValue((String) args[i], args[i + 1]);
        }
        return (List<T>) getSimpleJdbcTemplate().query(sql, beanMappingFactory.getBeanMapper(mapperClass), map);
    }

    public Long queryForLong(String sql) throws Exception {
        logQuery(sql, null);
        PreparedStatement ps = getConnection().prepareStatement(sql);
        ps.execute();
        ResultSet rs = ps.getResultSet();
        if (rs.next()) {
            return rs.getLong(1);
        }
        return null;
    }

    /**
     * Returns a collection of string values 
     * @param sql
     * @return
     * @throws Exception
     */
    public Collection<String> queryStrings(String sql) throws Exception {
        PreparedStatement ps = getConnection().prepareStatement(sql);
        logger.info(ps);

        ps.execute();
        ResultSet rs = ps.getResultSet();

        Collection<String> results = new LinkedList<String>();
        while (rs.next()) {
            results.add(rs.getString(1));
        }
        return results;
    }

    public <T> T querySingle(String sql, Class<T> mapperClass, Object... args) throws Exception {

        List<T> results = query(sql, mapperClass, args);

        if (results.size() > 0) {
            return results.get(0);
        }
        return null;
    }

    /**
     * Executes the SQL command and returns the long value of counts of entities
     * 
     * @param sql
     *            SQL command string
     * @param args
     *            An array of pairs of name and value for the
     *            {@link MapSqlParameterSource}
     * @return
     * @throws Exception
     */
    public Long count(String sql, Object... args) throws Exception {
        MapSqlParameterSource map = new MapSqlParameterSource();
        for (int i = 0; i < args.length; i += 2) {
            map.addValue((String) args[i], args[i + 1]);
        }
        return getSimpleJdbcTemplate().queryForLong(sql, map);
    }

    /**
     * Executes the SQL command for updating the entities in DB.
     * 
     * @param sql
     *            SQL command string
     * @param args
     *            An array of pairs of name and value for the
     *            {@link MapSqlParameterSource}
     * @return
     * @throws Exception
     */
    public int update(String sql, Object... args) throws Exception {
        logQuery(sql, args);
        if (args == null)
            return getSimpleJdbcTemplate().update(sql);

        MapSqlParameterSource map = new MapSqlParameterSource();
        for (int i = 0; i < args.length; i += 2) {
            map.addValue((String) args[i], args[i + 1]);
        }
        return getSimpleJdbcTemplate().update(sql, map);
    }

    public BeanMappingFactory getBeanMappingFactory() {
        return beanMappingFactory;
    }

    public void setBeanMappingFactory(BeanMappingFactory beanMappingFactory) {
        this.beanMappingFactory = beanMappingFactory;
    }

    /**
     * Used for logging the SQL command string
     * 
     * @param sql
     *            SQL command string
     * @param args
     *            An array of pairs of name and value for the
     *            {@link MapSqlParameterSource}
     */
    private void logQuery(String sql, Object[] args) {
        if (args != null) {
            for (int i = 0; i < args.length - 1; i += 2) {
                sql = sql.replace(":" + args[i], "" + args[i + 1]);
            }
        }
        logger.info(sql);
    }
}