基于Java web的网上订餐系统(源码+数据库).zip

package ch01.newer.restrant.utils; import java.beans.PropertyVetoException; import java.io.IOException; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.Properties; import com.mchange.v2.c3p0.ComboPooledDataSource; public class DBUtil { private static String driver = ""; private static String url = ""; private static String user = ""; private static String pwd = ""; private static Connection conn = null; private static PreparedStatement ps = null; private static ResultSet rs = null; private static ComboPooledDataSource source = null; static { init(); source = new ComboPooledDataSource(); try { source.setDriverClass(driver); source.setJdbcUrl(url); source.setUser(user); source.setPassword(pwd); source.setMaxPoolSize(100); source.setMaxIdleTime(500); source.setInitialPoolSize(20); source.setMinPoolSize(5); } catch (PropertyVetoException e) { System.out.println("创建数据库连接池错误！"); e.printStackTrace(); } } /** * 初始化数据库连接字符串 */ private static void init() { Properties p = new Properties(); try { p.load(DBUtil.class.getClassLoader().getResourceAsStream( "config.properties")); driver = p.getProperty("driver"); user = p.getProperty("user"); pwd = p.getProperty("pwd"); url = p.getProperty("url"); } catch (IOException e) { e.printStackTrace(); } } /** * 连接数据库 * * @return */ public static Connection getConnection() { try { conn = source.getConnection(); } catch (SQLException e) { System.out.println("未获得数据库连接！"); e.printStackTrace(); } return conn; } /** * 通用增删改查方法 * * @param sql * @param obj * @return */ public static boolean updateSQL(String sql, Object obj[]) { conn = getConnection(); boolean flag = false; if (sql != null || !"".equals(sql)) { try { ps = conn.prepareStatement(sql); if (obj != null) { for (int i = 0; i < obj.length; i++) { ps.setObject(i + 1, obj[i]); } } if (ps.executeUpdate() > 0) { flag = true; } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { closeAll(null, ps, conn); } } return flag; } /** * 通用查询方法 * * @param sql * @param obj * @return */ public static ResultSet querySQL(String sql, Object obj[]) { conn = getConnection(); if (sql != null || !"".equals(sql)) { try { ps = conn.prepareStatement(sql); if (obj != null) { for (int i = 0; i < obj.length; i++) { ps.setObject(i + 1, obj[i]); } } rs = ps.executeQuery(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return rs; } /** * 关闭所有连接 * * @param rs * @param ps * @param conn */ public static void closeAll(ResultSet rs, PreparedStatement ps, Connection conn) { try { if (rs != null) { rs.close(); rs = null; } if (ps != null) { ps.close(); ps = null; } if (conn != null) { conn.close(); conn = null; } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public static void main(String[] args) { new DBUtil(); System.out.println(getConnection()); } }