基于c3p0的jdbc資料源工具類

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實作的一個資料源工廠類
 */
public class DataSourceFactory {

    // 儲存所有建立的DataSource，程序停止時統一銷毀
    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);

        // 連接配接池中最小連接配接數
        dataSource.setMinPoolSize(1);
        // 連接配接池中最大連接配接數
        dataSource.setMaxPoolSize(20);
        // 檢查連接配接池空閑連接配接的時間間隔，機關：秒
        dataSource.setIdleConnectionTestPeriod(60);
        // 最大空閑時間，指定時間中連接配接未被使用則會被丢棄，機關：秒
        dataSource.setMaxIdleTime(3600);
        return dataSource;
    }

    /**
     * 關閉所有資料源并清空緩存
     * 如果正在建立DataSource，closeAll将等待建立完成後執行
     */
    public static void closeAll() {
        rwLock.writeLock().lock();
        try {
            for (ComboPooledDataSource dataSource : dsPool.values()) {
                dataSource.close();
            }
            dsPool.clear();
        } finally {
            rwLock.writeLock().unlock();
        }
    }

}