jsp+servlet+mysql登录注册记住密码功能

package com.sxt.utils; import java.io.IOException; import java.lang.reflect.Field; import java.lang.reflect.Method; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.List; import java.util.Properties; /** * 调用JDBC的公共类 * @author Administrator * */ public class SxtJdbcUtil { //声明一些变量存放配置信息 private static String className = ""; private static String url = ""; private static String user = ""; private static String password = ""; /** * 在类被加载的时候执行，而且只执行一次 */ static { try { //获取配置文件信息 Properties properties = new Properties(); properties.load(SxtJdbcUtil.class.getClassLoader().getResourceAsStream("sxtJdbcUtil.properties")); //开始获取配置的初始值 String datatype = properties.getProperty("datatype"); className = properties.getProperty(datatype + "Driver"); url = properties.getProperty(datatype + "Url"); user = properties.getProperty(datatype + "User"); password = properties.getProperty(datatype + "Password"); //加载驱动 Class.forName(className); } catch (IOException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } } /** * 创建一个连接 * @return */ public static Connection createConnection() { //声明一个连接 Connection connection = null; try { //获取一个连接 connection = DriverManager.getConnection(url, user, password); //将事务的自动提交关闭，每次都需要手动提交 connection.setAutoCommit(false); } catch (SQLException e) { System.err.println("创建连接失败,请检查连接参数:url[" + url + "]user[" + user + "]password[" + password + "]"); e.printStackTrace(); } return connection; } /** * 创建发送器 * @param connection * @return */ public static Statement createStatement(Connection connection) { Statement statement = null; try { statement = connection.createStatement(); } catch (SQLException e) { e.printStackTrace(); } return statement; } /** * 创建预处理发送器 * @param connection * @param sql * @return */ public static PreparedStatement createPreparedStatement(Connection connection, CharSequence sql) { PreparedStatement preparedStatement = null; try { preparedStatement = connection.prepareStatement(sql.toString()); } catch (SQLException e) { e.printStackTrace(); } return preparedStatement; } /** * 关闭连接释放资源 * @param connection * @param statement * @param resultSet */ public static void closeAll(Connection connection, Statement statement, ResultSet resultSet) { if (resultSet != null) { try { resultSet.close(); } catch (SQLException e) { e.printStackTrace(); } } if (statement != null) { try { statement.close(); } catch (SQLException e) { e.printStackTrace(); } } if (connection != null) { try { connection.close(); } catch (SQLException e) { e.printStackTrace(); } } } /** * 将结果集合里面的数据存放至对象 * @param resultSet * @param clazz */ public static <T> List<T> resultSet2List(ResultSet resultSet, Class<T> clazz) { //声明一个List List<T> list = new ArrayList<T>(); try { //获取当前类所有的属性 Field[] dfields = clazz.getDeclaredFields(); //首先遍历resultSet while (resultSet.next()) { //创建一个对象 T bean = clazz.getConstructor().newInstance(); //遍历属性 for (int i = 0; i < dfields.length; i++) { //获取属性的名字 String fieldName = dfields[i].getName(); //获取属性对应的值 Object fieldValue = resultSet.getObject(fieldName); //获取属性的set方法 String methodName = "set" + fieldName.toUpperCase().substring(0, 1) + fieldName.substring(1); //获取方法 Method setMethod = clazz.getMethod(methodName, dfields[i].getType()); //要将值设置给对象 setMethod.invoke(bean, fieldValue); } //然后将对象添加到List list.add(bean); } } catch (Exception e) { e.printStackTrace(); } return list; } /** * 将结果集合里面的数据存放至对象 * @param resultSet * @param clazz */ public static <T> T resultSet2bean(ResultSet resultSet, Class<T> clazz) { //声明一个List List<T> list = resultSet2List(resultSet, clazz); if (list != null && list.size() >= 1) { return list.get(0); } return null; } }