Java+JSP+Mysql实现Web用户信息管理系统

package com.sjsq.dao.impl; import com.sjsq.dao.UserDao; import com.sjsq.utils.DBUtil; import com.sjsq.vo.User; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; /** * @author shuijianshiqing * @date 2021/6/7 21:09 */ public class UserDaoImpl implements UserDao { /** * 查询所有用户 * @param sql * @param arr * @return */ @Override public List<User> selectAll(String sql, Object[] arr) { Connection con = null; PreparedStatement ps = null; ResultSet rs = null; try { // 1.连接数据库 con = DBUtil.getConnection(); // 2.预编译 ps = con.prepareStatement(sql); if (arr != null) { for (int i = 0; i < arr.length; i++) { // 传入sql的参数,向上转型,某个栏位的查询 ps.setObject(i + 1, arr[i]); } } // 3.执行sql rs = ps.executeQuery(); // 4.保存查询出来的数据到list List<User> userList = new ArrayList<>(); while (rs.next()) { User user = new User(); user.setUserId(rs.getInt("userId")); user.setUserAge(rs.getString("userAge")); user.setUserPN(rs.getString("userPN")); user.setUserJianjie(rs.getString("userJianjie")); user.setUserNum(rs.getString("userNum")); user.setUserPhone(rs.getString("userPhone")); user.setUserTime(rs.getString("userTime")); user.setUserName(rs.getNString("userName")); user.setUserPwd(rs.getNString("userPwd")); userList.add(user); } return userList; } catch (Exception e) { e.printStackTrace(); } finally { // 关闭链接，避免数据库连接过多 DBUtil.close(con, ps, rs); } return null; } /** * 通过userId查询用户 * @param userId * @return */ @Override public User selectUser(Integer userId) { Connection con = null; PreparedStatement ps = null; ResultSet rs = null; try { // 1.连接数据库 con = DBUtil.getConnection(); // 2.预编译 String sql = "select * from userinfo where userId = ?"; ps = con.prepareStatement(sql); ps.setInt(1,userId); // 3.执行sql rs = ps.executeQuery(); while (rs.next()){ User user = new User(); user.setUserId(rs.getInt("userId")); user.setUserAge(rs.getString("userAge")); user.setUserPN(rs.getString("userPN")); user.setUserJianjie(rs.getString("userJianjie")); user.setUserNum(rs.getString("userNum")); user.setUserPhone(rs.getString("userPhone")); user.setUserTime(rs.getString("userTime")); user.setUserName(rs.getNString("userName")); user.setUserPwd(rs.getNString("userPwd")); return user; } } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); }finally { // 关闭资源，避免出现异常 DBUtil.close(con,ps,rs); } return null; } /** * 新增用户 * @param user * @return */ @Override public boolean addUser(User user) { String sql = "insert into userinfo values (?,?,?,?,?,?,?,?,?)"; List<Object> list = new ArrayList<Object>(); list.add(user.getUserId()); list.add(user.getUserAge()); list.add(user.getUserPN()); list.add(user.getUserJianjie()); list.add(user.getUserNum()); list.add(user.getUserPhone()); list.add(user.getUserTime()); list.add(user.getUserName()); list.add(user.getUserPwd()); boolean flag = DBUtil.addUpdateDelete(sql,list.toArray()); if(flag){ return true; }else { return false; } } /** * 更新用户 * @param user * @return */ @Override public boolean updateUser(User user) { String sql = "update userinfo set userAge=?,userPN=?,userJianjie=?,userNum=?,userPhone=?,userTime=?,userName=?,userPwd=? where userId=?"; List<Object> list = new ArrayList<Object>(); list.add(user.getUserAge()); list.add(user.getUserPN()); list.add(user.getUserJianjie()); list.add(user.getUserNum()); list.add(user.getUserPhone()); list.add(user.getUserTime()); list.add(user.getUserName()); list.add(user.getUserPwd()); list.add(user.getUserId()); boolean flag = DBUtil.addUpdateDelete(sql,list.toArray()); if(flag){ return true; }else { return false; } } /** * 删除用户 * @param userId * @return */ @Override public boolean deleteUser(Integer userId) { String sql = "delete from userinfo where userId=?"; List<Object> list = new ArrayList<Object>(); list.add(userId); boolean flag = DBUtil.addUpdateDelete(sql,list.toArray()); if(flag){ return true; }else { return false; } } }