基于c3p0的jdbc数据源工具类

import com.mchange.v2.c3p0.ComboPooledDataSource;

import java.beans.PropertyVetoException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * c3p0实现的一个数据源工厂类
 */
public class DataSourceFactory {

    // 保存所有创建的DataSource，进程停止时统一销毁
    private static final Map<String, ComboPooledDataSource> dsPool = new ConcurrentHashMap<>();

    static synchronized ComboPooledDataSource getDataSource(String driver, String url, String user, String pass) {
        String dataSourceKey = driver + "_" + url + "_" + user;
        ComboPooledDataSource dataSource = dsPool.get(dataSourceKey);
        if (dataSource == null) {
            dataSource = makeDataSource(driver, url, user, pass);
            dsPool.put(dataSourceKey, dataSource);
        }
        return dataSource;
    }

    private static ComboPooledDataSource makeDataSource(String driver, String url, String user, String pass) {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();

        try {
            dataSource.setDriverClass(driver);
            System.out.println("JDBC Driver Class load completion:" + driver);
        } catch (PropertyVetoException e) {
        	System.out.println("JDBC Driver Class ["+driver+"] is not Found!");
            throw new RuntimeException("Please check your application.conf!", e);
        }
        dataSource.setJdbcUrl(url);
        dataSource.setUser(user);
        dataSource.setPassword(pass);

        // 连接池中最小连接数
        dataSource.setMinPoolSize(1);
        // 连接池中最大连接数
        dataSource.setMaxPoolSize(20);
        // 检查连接池空闲连接的时间间隔，单位：秒
        dataSource.setIdleConnectionTestPeriod(60);
        // 最大空闲时间，指定时间中连接未被使用则会被丢弃，单位：秒
        dataSource.setMaxIdleTime(3600);
        return dataSource;
    }

    /**
     * 关闭所有数据源并清空缓存
     * 如果正在创建DataSource，closeAll将等待创建完成后执行
     */
    public static void closeAll() {
        rwLock.writeLock().lock();
        try {
            for (ComboPooledDataSource dataSource : dsPool.values()) {
                dataSource.close();
            }
            dsPool.clear();
        } finally {
            rwLock.writeLock().unlock();
        }
    }

}