【java】兴唐第三十一节课之自己写的DBUtil

package com.zzxtit.common.util;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.sql.DataSource;

import com.alibaba.druid.pool.DruidDataSource;

/**
 * 
 * 
 * @author zzxt
 *
 */
public class DBUtil {

	private final static String DB_USERNAME = "root";
	private final static String DB_PASSWD = "root";
	private final static String DB_DRIVER = "com.mysql.jdbc.Driver";
	private final static String DB_URL = "jdbc:mysql://localhost:3306/test";
	
	private static DruidDataSource dds = null;
	
	static {
		dds = new DruidDataSource();
		dds.setUsername("root");
		dds.setPassword("root");
		dds.setUrl("jdbc:mysql://localhost:3306/test");
		dds.setDriverClassName("com.mysql.jdbc.Driver");
		dds.setInitialSize(5);//表示当连接池初始化后，在池中最少的链接数
		dds.setMaxActive(20);
	}
	
	/**
	 * 返回数据库链接
	 * @return
	 */
	public static Connection getDBConn() {
		try {
			return dds.getConnection();
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return null;
	}
	
	/**
	 * 
	 * @return
	 */
	public static DataSource getDS() {
		return dds;
	}
	
	public static void close(Connection conn) {
		try {
			if(conn != null) {
				conn.close();
			}
		}catch(SQLException e) {
			e.printStackTrace();
		}
	}
	
	public static void close(Statement stat) {
		try {
			if(stat != null) {
				stat.close();
			}
		}catch(SQLException e) {
			e.printStackTrace();
		}
	}
	
	public static void close(ResultSet rs) {
		try {
			if(rs != null) {
				rs.close();
			}
		}catch(SQLException e) {
			e.printStackTrace();
		}
	}
	
	public static void close(Connection conn, Statement stat, ResultSet rs) {
		close(rs);
		close(stat);
		close(conn);
	}
	
	public static void close(Connection conn, Statement stat) {
		close(stat);
		close(conn);
	}
}

注：

程序中有个方法返回了连接池，目的是以防将来要对连接池进行操作