技術雜記-改造具有監控功能的數據庫連接池阿里Druid，支持simple-jndi，kettle

　　kettle內置的jndi管理是simple-jndi，功能確實比較簡單，我需要監控kettle性能，druid確實是很不錯的選擇，但沒有提供對應的支持，我改進了druid源碼，實現了simple-jndi的接口，就可以在simple-jndi/jdbc.properties中配置druid數據源了，通過druid可以得到很多監控數據。

　　具體druid的使用請參考官方教程：https://github.com/alibaba/druid/wiki/%E9%A6%96%E9%A1%B5，相當詳細。

　　具體代碼如下：

/*
 * Copyright 1999-2101 Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.alibaba.druid.support.simplejndi;

import java.sql.SQLException;
import java.util.Properties;

import org.osjava.sj.loader.convert.Converter;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import com.alibaba.druid.support.logging.Log;
import com.alibaba.druid.support.logging.LogFactory;

/**
 * 支持simple-jndi
 * <h1>配置示例：</h1>
 * <pre>
pgDruidTest/converter=com.alibaba.druid.support.simplejndi.DruidDataSourceConverter
pgDruidTest/type=javax.sql.DataSource
pgDruidTest/driverClassName=org.postgresql.Driver
pgDruidTest/url=jdbc:postgresql://127.0.0.1:5432/kettleRep
pgDruidTest/username=postgres
pgDruidTest/password=postgres
pgDruidTest/maxActive=50
pgDruidTest/minIdle=10
pgDruidTest/initialSize=5
pgDruidTest/validationQuery=SELECT 1
pgDruidTest/maxWait=10000
pgDruidTest/removeabandoned=true
pgDruidTest/removeabandonedtimeout=60
pgDruidTest/logabandoned=false
pgDruidTest/filters=stat,config,log4j
pgDruidTest/connectionProperties=druid.log.stmt.executableSql=true
   </pre>
 * date: 2016年1月31日 下午12:54:10 
 * @author [e-mail]
 */
public class DruidDataSourceConverter implements Converter {

    private final static Log LOG = LogFactory.getLog(DruidDataSourceConverter.class);
    /**
     * 
     * @see org.osjava.sj.loader.convert.Converter#convert(java.util.Properties, java.lang.String)
     */
    @Override
    public Object convert(Properties properties, String type) {
        try {
            DruidDataSource dataSource = new DruidDataSource();
            DruidDataSourceFactory.config(dataSource, properties);
            return dataSource;
        } catch (SQLException e) {
            LOG.error("properties:"+properties, e);
        }
        return null;
    }

}

　　我已將以上改進pull requests到官方了，並已經合並，官方新版應該直接支持作為kettle的數據源配置了。