单例模式-饿汉式创建数据库连接详解编程语言

package com.jake.utils; 
 
import java.beans.PropertyVetoException; 
import java.sql.Connection; 
import java.sql.ResultSet; 
import java.sql.SQLException; 
import java.sql.Statement; 
 
import javax.sql.DataSource; 
 
import com.mchange.v2.c3p0.ComboPooledDataSource; 
 
public class C3P0Util {
    
 
	private static ComboPooledDataSource dataSource; 
	 
	static{
    
		 //从C3P0连接池中获取连接对象 
		dataSource = new ComboPooledDataSource(); 
	} 
	 
	/** 
	 * 获得连接对象 
	 * @return 
	 * @throws SQLException 
	 * @throws PropertyVetoException 
	 */ 
	public static Connection getConnection() throws SQLException, PropertyVetoException{
    
		 return dataSource.getConnection(); 
	} 
	 
	public static void close(ResultSet resultSet,Statement statement,Connection connection) throws SQLException{
    
		if (resultSet != null) {
    
			resultSet.close(); 
		} 
		if (statement != null) {
    
			statement.close(); 
		} 
		if (connection != null) {
    
			connection.close(); 
		} 
	} 
	 
	/** 
	 * 获得连接池对象 
	 * @return 
	 */ 
	public static DataSource getDataSource(){
    
		return dataSource; 
	} 
	 
}