//eg1,没有使用单实例，eg2有

package cn.itcast;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

public final class JdbcUtils {

private static String url = "jdbc:mysql://localhost:/xxxx";

private static String user = "";

private static String password = "";

private JdbcUtils() {

}

static {

try {

Class.forName("com.mysql.jdbc.Driver");

} catch (ClassNotFoundException e) {

// TODO Auto-generated catch block

throw new ExceptionInInitializerError(e);

}

}

public static Connection getConnection() throws SQLException {

return DriverManager.getConnection(url, user, password);

}

public static void free(ResultSet rs, Statement st, Connection conn) {

try {

if (rs != null)

rs.close();

} catch (SQLException e) {

e.printStackTrace();

} finally {

try {

if (st != null)

st.close();

} catch (SQLException e) {

e.printStackTrace();

} finally {

if (conn != null)

try {

conn.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}

}

}