My code review

package imp;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import tools.ConnectionManager;

import bean.User;
import dao.UserDao;
/*
用戶操作功能類
*/
public class UserDaoImp implements UserDao {
    //數據庫鏈接函數
    public Connection con = null;
    PreparedStatement ps = null;
    public ResultSet rs = null;
    /*
    添加用戶
    */
    @Override
    public int insertUse(User user) {
        int result = 0;//結果集
        con = ConnectionManager.getConnection();
        String sql = "insert into user(uId,uName,uPassword,uPhone,uAddress,uBalance) values(?,?,?,?,?,?)";

        try {
            ps = con.prepareStatement(sql);
            ps.setString(1, user.getuId());
            ps.setString(2, user.getuName());
            ps.setString(3, user.getuPassword());
            ps.setString(4, user.getuPhone());
            ps.setString(5, user.getuAddress());
            ps.setString(6, user.getuBalance());
            result = ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return result;
    }
    /*
    檢查用戶登錄
    */
    @Override
    public User checkUser(String uid, String upassword) {
        User user = new User();
        con = ConnectionManager.getConnection();
        String sql = "select * from user where uId=? and uPassword=?";//建立在用戶名和密碼是否匹配的基礎上
        try {
            ps = con.prepareStatement(sql);
            ps.setString(1, uid);
            ps.setString(2, upassword);
            rs = ps.executeQuery();
            if (rs.next() == false) {
                user.setuId("00000000");
            } else {
                user.setuId("uId");
            }

        } catch (SQLException e) {
            e.printStackTrace();
        }
        return user;
    }
    /*
    搜索用戶信息
    */
    @Override
    public User searchUser(String uid) {
        User user = new User();
        con = ConnectionManager.getConnection();
        String sql = "select * from user where uId=?";
        try {
            ps = con.prepareStatement(sql);
            ps.setString(1, uid);
            rs = ps.executeQuery();
            while (rs.next()) {
                user.setuId(rs.getString("uId"));
                user.setuName(rs.getString("uName"));
                user.setuPassword(rs.getString("uPassword"));
                user.setuAddress(rs.getString("uAddress"));
                user.setuPhone(rs.getString("uPhone"));
                user.setuBalance(rs.getString("uBalance"));
            }

        } catch (SQLException e) {
            e.printStackTrace();
        }
        return user;
    }
    /*
    列出用戶列表信息
    */
    @Override
    public List<User> getAllUser() {
        Connection con = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        List<User> list = new ArrayList<User>();
        try {
            con = ConnectionManager.getConnection();
            ps = con.prepareStatement("select * from user");
            rs = ps.executeQuery();
            while (rs.next()) {
                User user = new User();
                user.setuId(rs.getString("uId"));
                user.setuName(rs.getString("uName"));
                user.setuAddress(rs.getString("uAddress"));
                user.setuPhone(rs.getString("uPhone"));
                user.setuBalance(rs.getString("uBalance"));
                list.add(user);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return list;
    }
    /*
    更新管理員信息
    */
    @Override
    public int updateAdmin(String uid, User user) {
        int result = 0;
        con = ConnectionManager.getConnection();
        String sql = "UPDATE user SET uName=?, uPassword=?, uPhone=?, uAddress=?, uBalance=? WHERE `uId`=?;";//通過用戶ID進行修改

        try {
            ps = con.prepareStatement(sql);
            ps.setString(1, user.getuName());
            ps.setString(2, user.getuPassword());
            ps.setString(3, user.getuPhone());
            ps.setString(4, user.getuAddress());
            ps.setString(5, user.getuBalance());
            ps.setString(6, uid);
            result = ps.executeUpdate();
            if (result != 0) {
                result = 1;
            } else {
                result = 0;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return result;
    }
    /*
    刪除用戶
    */
    @Override
    public int deleteUser(String uid) {
        int result = 0;
        con = ConnectionManager.getConnection();
        String sql = "DELETE FROM user WHERE uId=?";//通過用戶ID的索引進行刪除

        try {
            ps = con.prepareStatement(sql);
            ps.setString(1, uid);
            result = ps.executeUpdate();
            if (result != 0) {
                result = 1;
            } else {
                result = 0;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return result;
    }
    /*
    更新用戶信息
    */
    @Override
    public int updateUser(String uid, User user) {
        int result = 0;
        con = ConnectionManager.getConnection();
        String sql = "UPDATE user SET uName=?, uPassword=?, uPhone=?, uAddress=? WHERE `uId`=?;";//通過用戶ID進行更新

        try {
            ps = con.prepareStatement(sql);
            ps.setString(1, user.getuName());
            ps.setString(2, user.getuPassword());
            ps.setString(3, user.getuPhone());
            ps.setString(4, user.getuAddress());
            ps.setString(5, uid);
            result = ps.executeUpdate();
            if (result != 0) {
                result = 1;
            } else {
                result = 0;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return result;
    }
    /*
    模糊查詢
    */
    @Override
    public List fuzzySearchUser(String uname) {
        Connection con = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        List<User> list = new ArrayList<User>();
        try {
            con = ConnectionManager.getConnection();
            ps = con.prepareStatement("select * from user where uname like '%"+uname+"%'");//用uname參數執行模糊查詢
            rs = ps.executeQuery();
            while (rs.next()) {
                User user = new User();
                user.setuId(rs.getString("uId"));
                user.setuName(rs.getString("uName"));
                user.setuAddress(rs.getString("uAddress"));
                user.setuPhone(rs.getString("uPhone"));
                user.setuBalance(rs.getString("uBalance"));
                list.add(user);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return list;
    }
}

以我現在的水平看過去自己所未能發現的問題，求輕噴，如果可以，也幫我改進下我的不合理之處，不甚感謝！

1.代碼注釋不詳細，每個類都沒有明確寫出功能（基本沒有注釋，上面的注釋都是后來加上的，現在才養起這個習慣並堅持下去）
2.有些參數沒有明確指定在哪里調用，可能會出現跑偏或用錯函數的問題
3.java.util.*慎用（我覺得這不像寫代碼的，像拐賣人口的）
4.雖說只要實現了功能就好，可還是要注意順序問題，最好有明確的順序，可以更好地找到功能並對應
5.最好不要使用組合聲明，應分開並注釋這些聲明分別對應哪些指定的函數操作。
6.入行時間太少，手太生，只關注了程序是否能跑起來，並未關注程序的嚴謹性和邏輯性。