DB

package com.bjsxt.shopping.util;import java.sql.*;public class DB {public static Connection getConn() {Connection conn = null;try {Class.forName("com.mysql.jdbc.Driver");conn = DriverManager.getConnection("jdbc:mysql://localhost/shopping?user=root&password=root");} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {e.printStackTrace();}return conn;}public static PreparedStatement prepare(Connection conn, String sql) {PreparedStatement pstmt = null; try {if(conn != null) {pstmt = conn.prepareStatement(sql);}} catch (SQLException e) {e.printStackTrace();}return pstmt;}public static PreparedStatement prepare(Connection conn, String sql, int autoGenereatedKeys) {PreparedStatement pstmt = null; try {if(conn != null) {pstmt = conn.prepareStatement(sql, autoGenereatedKeys);}} catch (SQLException e) {e.printStackTrace();}return pstmt;}public static Statement getStatement(Connection conn) {Statement stmt = null; try {if(conn != null) {stmt = conn.createStatement();}} catch (SQLException e) {e.printStackTrace();}return stmt;}/*public static ResultSet getResultSet(Connection conn, String sql) {Statement stmt = getStatement(conn);ResultSet rs = getResultSet(stmt, sql);close(stmt);return rs;}*/public static ResultSet getResultSet(Statement stmt, String sql) {ResultSet rs = null;try {if(stmt != null) {rs = stmt.executeQuery(sql);}} catch (SQLException e) {e.printStackTrace();}return rs;}public static void executeUpdate(Statement stmt, String sql) {try {if(stmt != null) {stmt.executeUpdate(sql);}} catch (SQLException e) {e.printStackTrace();}}public static void close(Connection conn) {try {if(conn != null) {conn.close();conn = null;}} catch (SQLException e) {e.printStackTrace();}}public static void close(Statement stmt) {try {if(stmt != null) {stmt.close();stmt = null;}} catch (SQLException e) {e.printStackTrace();}}public static void close(ResultSet rs) {try {if(rs != null) {rs.close();rs = null;}} catch (SQLException e) {e.printStackTrace();}}}